The angular dispersion of a prism depends on

The angle of incidence as well as the index of refraction

The thickness of the prism only

The momentum of a car moving at a constant speed in a circular track

can be zero depending on its position in the track

can be both positive and negative

can be zero depending on its position in the track

Ripple in a power supply unit is caused by

using an alternating current source

The mass of a nucleus is the

total number of its proton and neutrons

total number of its protons and electrons

Which of these is observed when air is pumped out of a discharge tube without lowering its pressure

the conductivity of the air increases

the conductivity of the air decreases

Aluminium is sometimes used as the leaf of an electroscope because it

can be converted into thin sheets

The pin-hole camera produces a less sharply defined image when the

screen is further from the pin-hole

object is further from the pin-hole

An alternating current can induce voltage because it has

weaker magnetic field than direct current

JAMB UTME - Physics - 2019 | Green Bridge CBT

Question 1 Report

A body moves in SHM between two point 20m on the straight line Joining the points. If the angular speed of the body is 5 rad/s. Calculate its speed when it is 6m from the center of the motion.

20 m/s

30 m/s

40 m/s

50 m/s

Answer Details

From two parts 20m apart
a = 10m, x = 6m, A = 5
V = ω

\sqrt{A^{2} - X^{2}}

= 5

\sqrt{10^{2} - 6^{2}}

= 40m/s

Read lesson note on Simple Harmonic Motion (WAEC)

Simple Harmonic Motion

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Question 2 Report

A mass of 0.5kg is whirled in a vertical circle of radius 2m at a steady rate of 2 rev/s. Calculate the centripetal force

164N

160N

158N

172N

Answer Details

The centripetal force is the force that acts towards the center and keeps an object moving in a circular path. To calculate the centripetal force, we can use the following formula: f = m * v^2 / r where: - f = centripetal force - m = mass of the object (0.5 kg) - v = velocity of the object (2 rev/s * 2 * pi m/rev = 12.57 m/s) - r = radius of the circle (2 m) Plugging in the values, we get: f = 0.5 kg * 12.57 m/s^2 / 2 m f = 31.43 N Rounding to the nearest whole number, the centripetal force is 31 N. So, the closest answer from the options is 160N.

Read lesson note on Temperature And Its Measurement (JAMB)

Read lesson note on Speed And Velocity (WAEC)

Read lesson note on Equilibrium Of Forces (WAEC)

Temperature And Its Measurement

Speed And Velocity

Equilibrium Of Forces

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Question 3 Report

Calculate the velocity ratio of a screw jack of pitch 0.2cm if the length of the tommy bar is 23cm

230

π

23

π

70

π

140

π

Answer Details

P = 0.2cm, L = r = 23cm

VR

=

2?rP

=

2?LP

=

2?×230.2

=

230?

Read lesson note on Simple Machines (JAMB)

Simple Machines

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Question 4 Report

The diagram above represents the stress-strain graph of a loaded wire. Which of these statements is correct?

At J, the wire becomes plastic

J is the yield point

L is the elastic limit

At K, the wire breaks

Answer Details

- I is the elastic limit
- the end of the constant part J is the yield point
- L is the break point.

Read lesson note on Elasticity (JAMB)

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Elasticity

Measurements And Units

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Question 5 Report

If a body moves with a constant speed and at the same time undergoes an acceleration, its motion is said to be

circular

oscillatory

rectilinear

rotational

Answer Details

If a body moves with a constant speed and at the same time undergoes an acceleration, its motion is said to be rectilinear. When an object moves with constant speed, it means that it covers the same distance in equal time intervals. On the other hand, acceleration is the rate of change of velocity with time. If an object undergoes acceleration, its velocity changes with time. Therefore, if a body moves with constant speed and undergoes an acceleration, it means that its direction of motion changes while it covers equal distances in equal time intervals. This type of motion is called rectilinear motion, where the object moves in a straight line, but its velocity changes due to the acceleration. In contrast, circular motion is when an object moves in a circular path with a constant speed, while oscillatory motion is when an object moves back and forth around a fixed point. Rotational motion is when an object rotates around an axis. None of these descriptions fit the scenario of a body moving with constant speed and undergoing acceleration, so the answer is rectilinear motion.

Read lesson note on Motion (JAMB)

Motion

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Question 6 Report

Electrons were discovered by

Dalton

James Charwick

J.J. Thompson

Niels Bohr

Answer Details

Electrons were discovered by J.J. Thompson. In the late 19th century, he performed a series of experiments using cathode ray tubes, which are glass tubes containing low-pressure gas and electrodes. By applying high voltage, he observed a beam of negatively charged particles traveling from the negative electrode to the positive electrode. He concluded that these particles, which he called "corpuscles," were fundamental units of negative charge and later were renamed electrons. This discovery led to the development of the modern understanding of atomic structure and the electron's role in it.

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Structure Of The Atom (Nigeria Only)

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Question 7 Report

A train has an initial velocity of 44m/s and an acceleration of -4m/s$^{2}$. Calculate its velocity after 10 seconds

10m/s

6m/s

8m/s

4m/s

Answer Details

The velocity of the train after 10 seconds can be calculated using the formula: v = u + at where v is the final velocity, u is the initial velocity, a is the acceleration, and t is the time. Substituting the given values, we get: v = 44 m/s + (-4 m/s^2) x 10 s v = 44 m/s - 40 m/s v = 4 m/s Therefore, the velocity of the train after 10 seconds is 4m/s. Answer option D is correct. Explanation: The train has an initial velocity of 44 m/s and an acceleration of -4 m/s^2. The negative sign indicates that the acceleration is in the opposite direction to the initial velocity, which means that the train is slowing down. After 10 seconds, the train's velocity decreases by 40 m/s (4 m/s^2 x 10 s) to reach a final velocity of 4 m/s.

Read lesson note on Motion (JAMB)

Motion

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Question 8 Report

If the time of flight is 96seconds, calculate the horizontal range through the point of projection.

84400m

69000m

61440m

24000m

Answer Details

Time of flight, T = 96s
R = (Ucosθ) *time* T = 640 × 96 = 61,440m

Read lesson note on Motion (JAMB)

Motion

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Question 9 Report

A supply of 400V is connected across capacitors of 3μf and 6μf in series. Calculate the charge

8 x 10

^{- 4}

C

4 x 10

^{- 2}

C

8 x 10

^{- 3}

C

4 x 10

^{- 8}

C

Answer Details

C

_{T}

=

C

_{1}

× C

_{2}

C

_{1}

+ C

_{2}

=	3 × 63 + 6

= $\frac{18}{9}$ = 2μf
Q = CV
⇒ 2 × 10 $^{- 6}$ × 400
⇒ 800 × 10 $^{- 6}$ C = 8 × 10 $^{- 4}$ C

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Capacitors

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Question 10 Report

A boy pushes a 500kg box along a floor with a force of 2000N. If the velocity of the box is uniform, the co-efficient of friction between the box and the floor is

1

0.8

0.65

0.4

Answer Details

The coefficient of friction is a measure of the amount of friction between two surfaces. It is represented by the symbol "μ" and is a dimensionless quantity. The coefficient of friction between two surfaces depends on the nature of the surfaces in contact and the force pressing them together. In this problem, the boy is pushing the box with a force of 2000N. If the box is moving with a uniform velocity, then the force of friction acting on the box is equal and opposite to the pushing force applied by the boy. We can calculate the force of friction using the formula: frictional force = coefficient of friction x normal force where the normal force is the force exerted by the floor on the box in a direction perpendicular to the floor. Since the box is not moving up or down, the normal force is equal to the weight of the box. The weight of the box can be calculated using the formula: weight = mass x gravity where mass is the mass of the box and gravity is the acceleration due to gravity (9.8 m/s^2). So, the weight of the box is: weight = 500 kg x 9.8 m/s^2 = 4900 N The force of friction is equal to the pushing force of 2000N, so we can set these two equal to each other and solve for the coefficient of friction: frictional force = 2000N coefficient of friction x normal force = 2000N coefficient of friction x 4900N = 2000N coefficient of friction = 2000N / 4900N = 0.408 So, the coefficient of friction between the box and the floor is approximately 0.4. Therefore, the correct answer is 0.4.

Read lesson note on Equilibrium Of Forces (WAEC)

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Equilibrium Of Forces

Measurements And Units

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Question 11 Report

- angle of dip is zero at the magnetic equator
- angle of variation is the same as angle of declination.

angle of variation is zero

magnetic declination is 90

angle of dip is zero

horizontal component at the Earth's field is zero

Answer Details

- angle of dip is zero at the magnetic equator
- angle of variation is the same as angle of declination.

Read lesson note on Magnetic Field (Part 2) (WAEC)

Read lesson note on Electric Field (WAEC)

Magnetic Field (Part 2)

Electric Field

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Question 12 Report

The pitch of a screw jack is 0.45cm and the arm is 60cm long. If the efficiency of the Jack is 75/π %, calculate the mechanical advantage.

400

300

200

150

Answer Details

P = 0.45cm, L = 60cm, Eff = 75/π%

VR

(Screw

system)

=

2πrP

=

2πLP

M.A

=

Eff% × VR100

=

75π

×

1100

×

2π × 600.45

=

75 × 800300

=

200

Read lesson note on Simple Machines (JAMB)

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Simple Machines

Measurements And Units

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Question 13 Report

The conductivity of gases at low pressure can be termed as

I. hot cathode emission

II. thermo ionic emission

III. cold cathode emission

IV. Field emission

I and II

II and III

III and IV

IV and V

Answer Details

As conduction of gases is at low pressure and high voltage, called field or cold cathode emission.

Read lesson note on Properties Of Waves: Reflection, Refraction, Diffraction (WAEC)

Properties Of Waves: Reflection, Refraction, Diffraction

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Question 14 Report

A coil X is moved quickly away from the end Y of a stationary metal bar and a current then flows in X as shown above.

Then

the bar is not a magnet

Y is a north pole

Y is a South pole

Y repels coil X

Answer Details

N - S magnet is moved towards a coil production clockwise direction of current in the coil.
- This is the same as a coil moved away from S-N (Y - North pole)

Read lesson note on Electromagnetic Field (Part 2) (WAEC)

Read lesson note on Electromagnetic Field (Part 1) (WAEC)

Electromagnetic Field (Part 2)

Electromagnetic Field (Part 1)

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Question 15 Report

A safety precaution designed to prolong the life of a lead acid accumulator is

By topping up the cells with concentrated acid

The use of naked flame when charging the battery

Keeping the specific gravity of the electrolyte within specified range

By connecting wires to the terminals directly when testing the level of charging

Answer Details

- Topping is done with distilled water
- Naked flame should be avoided when charging the battery
- Direct connection of wires to the terminals should be avoided.

View Answer

Question 16 Report

If the attraction of the sun is suddenly ceased, the earth would continue to move in a straight line making a tangent with the original orbit. This statement is derived from Neutron's

First law of motion

Second law of motion

Third law of motion

Law of universal gravitation

Answer Details

The correct answer is the First law of motion. The First law of motion, also known as the law of inertia, states that an object will remain at rest or in uniform motion in a straight line unless acted upon by an external force. In this case, the earth is moving in its orbit around the sun because of the force of gravity between the two objects. If the force of gravity suddenly ceased, the earth would no longer be acted upon by an external force and would continue to move in a straight line, making a tangent with its original orbit. This idea is attributed to Sir Isaac Newton, who developed the laws of motion and the law of universal gravitation. However, the specific statement mentioned in the question is derived from the First law of motion.

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Newton’s Laws Of Motion

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Question 17 Report

A metal rod has a length of 100cm at $200^\circ C$. At what temperature will its length be 99.4cm. If the linear expansivity of the material of the rod is $2 \times 10^{-5}C^{-1}$

200

^{o}

C

300

^{o}

C

100

^{o}

C

-100

^{o}

C

Answer Details

The linear expansivity of a material describes how its length changes with temperature. If the linear expansivity is given as 2 × 10^-5/°C, this means that for every 1°C change in temperature, the length of the material will change by 2 × 10^-5 times its original length. Given that the rod has a length of 100 cm at 200°C, we can use this information to find its length at a different temperature. If we let L be the length of the rod at temperature T, we can write the relationship as follows: L = 100 cm * (1 + 2 × 10^-5 * (T - 200°C)) To find the temperature at which the rod will have a length of 99.4 cm, we can set L equal to 99.4 cm and solve for T: 99.4 cm = 100 cm * (1 + 2 × 10^-5 * (T - 200°C)) 99.4 cm / 100 cm = 1 + 2 × 10^-5 * (T - 200°C) 0.994 = 1 + 2 × 10^-5 * (T - 200°C) -0.006 = 2 × 10^-5 * (T - 200°C) -0.006 / 2 × 10^-5 = T - 200°C -0.006 / (2 × 10^-5) = T - 200°C -0.006 / (2 × 10^-5) + 200°C = T So the temperature at which the rod will have a length of 99.4 cm is approximately equal to -0.006 / (2 × 10^-5) + 200°C, or -100°C. Therefore, the answer is -100°C.

Read lesson note on Thermal Expansion (JAMB)

Read lesson note on Temperature And Its Measurement (JAMB)

Thermal Expansion

Temperature And Its Measurement

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Question 18 Report

Gases conduct electricity under

high pressure and high voltage

low pressure and low voltage

normal pressure and low voltage

low pressure and high voltage

Answer Details

Gases conduct electricity under low pressure and high voltage

Read lesson note on Gas Laws (JAMB)

Gas Laws

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Question 19 Report

A vibrator causes water ripples to travel across the surface of a tank. The wave travels 50cm in 2s and the distance between successive crests is 5cm. Calculate the frequency of the vibrator

5Hz

6Hz

5.2Hz

25Hz

Answer Details

The frequency of the vibrator can be calculated using the formula: frequency = speed / wavelength where speed is the speed of the wave, and wavelength is the distance between successive crests. In this case, we are given that the wave travels 50cm in 2s, which means the speed of the wave is: speed = distance / time = 50cm / 2s = 25cm/s We are also given that the distance between successive crests is 5cm, which is the wavelength. Therefore, the frequency of the vibrator is: frequency = speed / wavelength = 25cm/s / 5cm = 5Hz So the correct answer is 5Hz.

Read lesson note on Motion (WAEC)

Motion

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Question 20 Report

If a body moves with a constant speed and at the same time undergoes an acceleration, its motion is said to be

oscillation

circular

rotational

rectilinear

Answer Details

If a body moves with a constant speed but at the same time undergoes an acceleration, its motion is called rectilinear motion. This means that the body moves in a straight line and its speed changes at a constant rate, causing an acceleration. It is different from oscillation, circular and rotational motions which involve changes in direction, as well as changes in speed.

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Rectilinear Acceleration

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Question 21 Report

Heat may be transferred by conduction, convention and radiation. By which of these methods does heat travel through vacuum?

Conduction only

Convection only

Radiation only

All these methods

Answer Details

Heat can be transferred by conduction, convection, and radiation. Conduction is the transfer of heat through a material by the movement of heat-carrying particles, such as atoms or molecules, from one part of the material to another. This method of heat transfer is not possible in a vacuum, as there are no particles present to carry heat. Convection is the transfer of heat by the movement of a fluid, such as air or water. This method of heat transfer is also not possible in a vacuum, as there are no fluids present to carry heat. Radiation is the transfer of heat through electromagnetic waves, such as light or infrared radiation. This method of heat transfer does not require any material or fluid medium, and can therefore occur in a vacuum. Therefore, the answer is "Radiation only".

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Heat Transfer

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Question 22 Report

A body was slightly displaced from its equilibrium position. Which one of the following is a condition for its stable equilibrium

an increase in the kinetic energy of the body

an increase in the potential energy of the body

an increase in the height of the body

Answer Details

The condition for stable equilibrium of a body that has been slightly displaced from its equilibrium position is "an increase in the potential energy of the body." When an object is at its equilibrium position, it has a minimum potential energy. When the object is displaced from its equilibrium position, it has a higher potential energy. For the object to be in stable equilibrium, it must be able to return to its equilibrium position after it has been displaced. If the potential energy of the object increases as it is displaced, it means that the equilibrium position is a point of stable equilibrium. This is because the object will experience a restoring force that will push it back towards its equilibrium position, as the potential energy decreases. Therefore, an increase in potential energy is a condition for a body to be in stable equilibrium after it has been slightly displaced from its equilibrium position. An increase in kinetic energy or height does not necessarily indicate stability, as it depends on the specific situation and other factors at play.

Read lesson note on Newton’s Laws Of Motion (WAEC)

Read lesson note on Scalars And Vectors (JAMB)

Read lesson note on Equilibrium Of Forces (WAEC)

Newton’s Laws Of Motion

Scalars And Vectors

Equilibrium Of Forces

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Question 23 Report

Which of the following statements is/are correct for a freely falling body?

I. the total is entirely kinetic

II. the ratio of potential energy to kinetic energy is constant

III. the sum of potential and kinetic energy is constant

I only

II only

III only

I and III only

Answer Details

The correct answer is "III only". A freely falling body is one that is falling under the influence of gravity and experiences no other force or constraint. In this situation, the total energy of the body is conserved, meaning that the sum of its potential and kinetic energy remains constant. The potential energy of a body is directly proportional to its height above the ground, and its kinetic energy is directly proportional to its velocity. As the body falls, its potential energy decreases and its kinetic energy increases, but the total energy remains constant. Statement III is correct because the sum of potential and kinetic energy is indeed constant for a freely falling body. Statement I is incorrect because the body has both potential and kinetic energy, so the total energy is not entirely kinetic. Statement II is incorrect because the ratio of potential energy to kinetic energy is not constant for a freely falling body, as both are changing as the body falls.

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Work, Energy And Power

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Question 24 Report

Neutrons were discovered by

Faraday

Dalton

James Chadwick

Rutherford

Answer Details

Neutrons were discovered by James Chadwick. In 1932, he conducted an experiment in which he bombarded a thin sheet of beryllium with alpha particles. He observed that a new type of radiation was emitted that was not affected by electric or magnetic fields. He concluded that this radiation was composed of particles that were neutral and had a mass similar to that of a proton. He called these particles "neutrons," and his discovery revolutionized our understanding of atomic structure and led to the development of nuclear energy.

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Structure Of The Atom (Nigeria Only)

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Question 25 Report

A microscope is focused on a mark on a table, when the mark is covered by a plate of glass 2m thick, the microscope has to be raised 0.67cm for the mark to be once more in focus. Calculate the refractive index.

1.52

1.68

2.58

1.82

Answer Details

R = th = 2cm, d = 0.67cm

n

=

RA

=

RR.d

=

22-0.67

=

1.52

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Refraction Of Light Through Plane And Curved Surfaces

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Question 26 Report

A single force which produces the same effect as a set of forces acting together at a point is known as the

component

equilibrant

resultant

resistant

Answer Details

The single force which produces the same effect as a set of forces acting together at a point is known as the "resultant". In other words, the resultant is the net force that results from combining all the individual forces acting on an object. It represents the combined effect of all the forces acting on the object and is the force that would produce the same motion as the original set of forces acting together. Therefore, when solving problems in physics, it is often useful to find the resultant force in order to determine the overall effect of multiple forces on an object.

Read lesson note on Scalars And Vectors (WAEC)

Read lesson note on Simple A.C Circuits (JAMB)

Read lesson note on Equilibrium Of Forces (WAEC)

Scalars And Vectors

Simple A.C Circuits

Equilibrium Of Forces

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Question 27 Report

A ray of light passes through the centre of curvature of a concave mirror and strikes the mirror. At what angle is the ray reflected?

180

^{o}

90

^{o}

0

^{o}

60

^{o}

Answer Details

When a light ray passes through the center of curvature of a concave mirror and strikes the mirror, the reflected ray will be reflected back on itself, creating an angle of 0 degrees. Therefore, the correct answer is 0o.

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Question 28 Report

The resultant capacitance in the figure above is

0.4μf

0.8μf

1.8μf

4.5μf

Answer Details

For the parallel arrangement = 2 + 4 = 6μf

For

the

series

arrangement

=

1C

_{T}

=

12

+

13

+

16

+

14

1C

_{T}

=

1512

C

_{T}

=

1215

=

0.8μf

Read lesson note on Capacitors (JAMB)

Capacitors

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Question 29 Report

Which of the following readings cannot be determined with a meter rule?

2.56cm

2.25cm

2.50cm

2.05cm

Answer Details

Meter rule has a reading accuracy of 0.5mm or 0.05cm, thus measurement is M ± 0.05cm i.e 2.00, 2.05, 2.50, 2.55 etc.
The reading that cannot be read is 2.56cm.

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Measurements And Units

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Question 30 Report

When two objects A and B are supplied with the same quantity of heat, the temperature change in A is obtained to be twice that of B. The mass of P is half that of Q. The ratio of the specific heat capacity of A to B is

1 : 4

4 : 1

1 : 1

2 : 1

Answer Details

θA = 2θ $_{B}$ ,

m

_{A}

=

12

m

_{B}

H = MCθ
m $_{A}$ c $_{A}$ θ $_{A}$ = m $_{B}$ c $_{B}$ θ $_{B}$
( 1/2 m $_{B}$ )C $_{A}$ (2θ $_{B}$ ) = m $_{B}$ c $_{B}$ θ $_{B}$

C

_{A}

C

_{B}

=

11

⇒ 1 : 1

Read lesson note on Temperature And Its Measurement (JAMB)

Temperature And Its Measurement

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Question 31 Report

Which of the following bodies, each with centre of gravity G, lying on a horizontal table, is/are in unstable equilibrium?

II only

III only

I and IV only

II and III only

Answer Details

- I and II are in neutral equilibrium. They will roll continuously on the table
- III is a body with high centre of gravity (unstable)
- IV is a body with high centre of gravity (stable)

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Equilibrium Of Forces

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Question 32 Report

The part of the human eye that does similar work as the diaphragm of a camera lens is the

Ciliary muscles

Pupil

Iris

Retina

Answer Details

The part of the human eye that does similar work as the diaphragm of a camera lens is the iris. The iris is the colored part of the eye and is responsible for controlling the amount of light that enters the eye. Just like the diaphragm in a camera lens, the iris can adjust its size to allow more or less light into the eye. This helps to regulate the amount of light reaching the retina, which is responsible for sensing light and transmitting the image to the brain.

Read lesson note on Structure Of The Atom (Nigeria Only) (WAEC)

Structure Of The Atom (Nigeria Only)

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Question 33 Report

A rectangular solid black has length 10cm, breadth 5cm and height 2cm. If it lies on a horizontal surface, and has density $100\text{kg/m}^3$, calculate the pressure it exerts on the surface.

200 N/m

^{2}

100 N/m

^{2}

400 N/m

^{2}

Answer Details

To calculate the pressure that the rectangular solid exerts on the surface, we need to use the formula for pressure: Pressure = Force / Area In this case, the force is the weight of the rectangular solid, which we can calculate using the formula: Weight = Mass x Gravity The mass of the rectangular solid can be calculated using its density and volume: Mass = Density x Volume The volume of the rectangular solid is simply its length x breadth x height: Volume = Length x Breadth x Height = 10 cm x 5 cm x 2 cm = 100 cm3 We need to convert this volume to cubic meters to use the density given in kg/m3: Volume = 100 cm3 = 0.0001 m3 Now we can calculate the mass: Mass = Density x Volume = 100 kg/m3 x 0.0001 m3 = 0.01 kg The gravity is the acceleration due to gravity, which we can assume to be 9.81 m/s2. Therefore, the weight is: Weight = Mass x Gravity = 0.01 kg x 9.81 m/s2 = 0.0981 N Now we can use this weight to calculate the pressure on the surface. The surface area in contact with the rectangular solid is simply its length x breadth: Area = Length x Breadth = 10 cm x 5 cm = 50 cm2 We need to convert this area to square meters: Area = 50 cm2 = 0.005 m2 Therefore, the pressure is: Pressure = Force / Area = 0.0981 N / 0.005 m2 = 19.62 N/m2 We can convert this to units of N/cm2 or N/mm2 if desired. This is equivalent to: Pressure = 0.1962 N/cm2 = 0.0001962 N/mm2 So the pressure that the rectangular solid exerts on the surface is 19.62 N/m2, which is approximately 20 N/m2. Therefore, the answer is 200 N/m2.

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Pressure

Measurements And Units

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Question 34 Report

The limiting frictional force between two surfaces depends on

I. the normal reaction between the surfaces

II. the area of surface in contact

III. the relative velocity between the surfaces

IV. the nature of the surfaces

I only

II only

III only

I and IV only

Answer Details

- Friction depends on the nature of the surfaces in contact
- Solid friction is independent of the area of the surfaces in contact and the relative velocity between the surfaces.

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Friction

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Question 35 Report

Efficiency of conduction in liquids and gases compared to solids is

less efficient than solid

more efficient than solids

equally efficient to solids

efficiently may vary

Answer Details

The efficiency of conduction in liquids and gases compared to solids is generally less efficient. This means that solids are better conductors of heat and electricity than liquids and gases. This is because the particles in solids are closely packed and are tightly bound to one another, allowing heat and electricity to flow easily through the material. On the other hand, the particles in liquids and gases are more spread out and less tightly bound, making it more difficult for heat and electricity to flow through these materials. However, it is important to note that the efficiency of conduction can vary depending on the specific liquid or gas and the specific solid being compared. Some liquids and gases may have properties that make them better conductors than certain solids, but this is not a general rule.

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Question 36 Report

Which of the following statement about the electromagnet shown above is correct?

when the current flows from A to B, the end A will be in north pole

when the current flows from A to B, the end A will be south pole

when the current flows from A to B, the end B will be north pole

none of the above

Answer Details

A - B = S - N.
Also, starting end of the current is south while terminating end is North.

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Electric Field

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Question 37 Report

The equilibrium position of objects in any field corresponds to situation of

equipotential energy

maximum potential energy

minimum potential energy

maximum kinetic energy

Answer Details

The equilibrium position of an object in any field corresponds to the situation of minimum potential energy. This means that at the equilibrium position, the object has the lowest possible potential energy within the field. In other words, the forces acting on the object are balanced, and the object is not being pushed or pulled in any direction. Therefore, the object will remain at rest at the equilibrium position unless it is acted upon by an external force. Of the options given, the correct answer is "minimum potential energy".

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Read lesson note on Measurements And Units (JAMB)

Gravitational Field

Measurements And Units

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Question 38 Report

The Earth's magnetic equator passes through Jos in Nigeria. At Jos, the

angle of variation is zero

magnetic declination is 90

angle of dip is zero

horizontal component at the Earth's field is zero

Answer Details

The Earth has a magnetic field that is generated by the movement of molten iron in its core. The magnetic field has different properties at different locations on the Earth's surface. The magnetic equator is an imaginary line on the Earth's surface where the inclination or tilt of the Earth's magnetic field is zero, meaning that the magnetic field lines are parallel to the Earth's surface. At Jos, Nigeria, the Earth's magnetic equator passes through, which means that the angle of inclination or dip of the Earth's magnetic field is zero. Therefore, the correct answer is that the angle of dip is zero. This means that a magnetic needle suspended by a thread or placed on a horizontal surface would remain horizontal and not point downwards or upwards, as it would at other locations on the Earth's surface. This makes Jos an important location for studying the Earth's magnetic field and for conducting experiments related to magnetism.

Read lesson note on Electromagnetic Field (Part 2) (WAEC)

Electromagnetic Field (Part 2)

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Question 39 Report

The mass of water vapour in a given volume of air is 0.05g at 20°C, while the mass of water vapour required to saturate it at the same temperature is 0.15g. Calculate the relative humidity of the air.

3.33%

5.55%

33.33%

55.55%

Answer Details

Relative humidity is a measure of how much water vapor the air is holding compared to the maximum amount it could hold at a given temperature. It is expressed as a percentage. To calculate the relative humidity of the air in this problem, we need to use the formula: Relative humidity = (mass of water vapor in air / mass of water vapor required for saturation) x 100% We are given that the mass of water vapor in the air is 0.05g and the mass of water vapor required for saturation at the same temperature is 0.15g. Plugging these values into the formula, we get: Relative humidity = (0.05 / 0.15) x 100% = 33.33% Therefore, the relative humidity of the air is 33.33%. So the answer is 33.33%.

Read lesson note on Quantity Of Heat (JAMB)

Quantity Of Heat

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Question 40 Report

Three resistors with resistance 200Ω, 500Ω and 1kΩ are connected in series. A 6v battery is connected to either end of the combination. Calculate the potential difference between the ends of 200Ω resistance.

0.71V

0.7V

0.82V

0.8V

Answer Details

To calculate the potential difference between the ends of the 200Ω resistance, we need to use Ohm's Law, which states that the potential difference (V) across a resistor is equal to the current (I) flowing through the resistor multiplied by the resistance (R) of the resistor. First, we need to find the total resistance of the series combination of resistors. We add up the individual resistances: Total resistance = 200Ω + 500Ω + 1kΩ = 1.7kΩ Next, we can use Ohm's Law to find the current flowing through the circuit. We know that the battery voltage is 6V, and the total resistance is 1.7kΩ: I = V / R = 6V / 1.7kΩ = 0.0035A Now we can use Ohm's Law again to find the potential difference across the 200Ω resistor: V = IR = 0.0035A * 200Ω = 0.7V Therefore, the potential difference between the ends of the 200Ω resistance is 0.7V. The correct answer is option B.

Read lesson note on Current Electricity (JAMB)

Current Electricity

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