Which of the following does NOT describe the Image formed by a plane minor?

Same distance from mirror as object

Which of the following is true of an electrical charge?

Positive charge means deficit electrons

Negative charge means excess of electrons

electric current means movement of electrons

The time rate of loss of heat by a body is proportional to the

difference in temperature between the body and its surroundings

temperature of its surroundings

difference in temperature between the body and its surroundings

ratio of the temperature of the body to that of its surroundings

The photo cell works on the principle of the

Emission of electron by incident radiation

Emission of protons by incident radiation

Electrical appliances in homes are normally earthed so that

a person touching the appliances is safe from electric shock

both the a.c. and d.c. sources can be used

the appliances are maintained at a higher pd than the earth

the appliances are maintained at a lower pd than the earth

Which of the following best describes the energy changes which take place when a steam engine drives a generator which lights a lamp?

heat ----> Kinetic ----> Electricity ----> Heat and Light

heat ----> Light----> Sound ----> Kinetic

Kinetic ----> Light ----> Heat ----> Electricity

heat ----> Kinetic ----> Electricity ----> Heat and Light

electricity ----> Kinetic ----> Heat ----> Light

JAMB UTME - Physics - 2018 | Green Bridge CBT

Question 1 Report

A lens of focal length 15cm forms on erect image which is three times the size of the object. The distance between the object and the image is ___.

10cm

20cm

30cm

40cm

Optical Instruments

View Answer

Question 2 Report

A pulley system has three pulleys in the fixed block and two in the movable block and if the pulley has an efficiency of 72%, the mechanical advantage of the system is?

36.0

7.2

5.0

3.6

View Answer

Question 3 Report

In homes, electrical appliances and lamps are connected in parallel because

less current will be used

less voltage will be used

parallel connection does not heat up the wires

series connection uses high voltage

Electrostatics

View Answer

Question 4 Report

Convex mirrors are used as driving mirrors because images formed are

erect, Virtual and diminished

erect, real and diminished

erect, virtual and magnified

inverted, virtual and diminished

Simple A.C. Circuits

View Answer

Question 5 Report

A narrow beam of white light can be split up into different colours by a glass prism. The correct explanation is that

white light Is an electromagnetic wave

the prism has all the colours of the white light

different colours of white light travel with different speeds in glass

white light has undergone total Internal reflection in the prism

Answer Details

The correct explanation for why a narrow beam of white light can be split up into different colors by a glass prism is that different colors of white light travel with different speeds in glass. White light is made up of different colors with different wavelengths, ranging from violet to red. When a narrow beam of white light passes through a glass prism, the different colors refract at slightly different angles due to the fact that their wavelengths are different. This causes the different colors to spread out and form a spectrum. The amount of refraction that occurs depends on the speed of light in the medium. Different colors of light have different speeds in glass due to the fact that their wavelengths are different. This means that they will refract at different angles as they pass through the glass prism, causing them to spread out. So, the correct explanation for why a narrow beam of white light can be split up into different colors by a glass prism is that different colors of white light travel with different speeds in glass. Therefore, is the correct explanation. is incorrect because it describes what white light is made up of, but does not explain how it is split up into colors by a prism. is incorrect because a prism does not have all the colors of white light, but rather it separates the colors that are already present in white light. is incorrect because total internal reflection occurs when light is completely reflected back into the same medium, which is not what happens when white light is split up by a prism.

Read lesson note on Electromagnetic Waves: Types Of Radiation In Electromagnetic Spectrum (WAEC)

Electromagnetic Waves: Types Of Radiation In Electromagnetic Spectrum

View Answer

Question 6 Report

Natural radioactivity consists of the emission of

α- particles and β-rays

α- particles and X-rays

α- particles, β - rays and g-rays

γ- rays and X-rays

Electromagnetic Field (Part 2)

Temperature And Its Measurement

View Answer

Question 7 Report

What is the resultant resistance of the circuit in the image shown?

8Ω

11Ω

4Ω

3.6Ω

Capacitors

View Answer

Question 8 Report

A body of mass 100g moving with a velocity if 10ms-1 collides with a wall. If after collision it moves with a velocity of 2.0ms−1 in the opposite direction, calculate the change in momentum.

0.8Ns

1.2Ns

12.0Ns

80.0Ns

Answer Details

Momentum = Mass x Velocity
Change in Momentum = Mass x (change in velocity)
Change in Momentum = Mass x (v - u)
Mass = 100g = 0.1kg
U = 2ms

^{- 1}

V = 10ms

^{- 1}

Change in momentum = m (v − u)
= 0.1 (10 − 2)
= 0.1 (8)
= 0.8Ns

Read lesson note on Motion (JAMB)

Motion

View Answer

Question 9 Report

What type of reaction is represented by the following scheme?

\( {}_{1}^{2}X + {}_{1}^{2}Y \longrightarrow {}_{2}^{3}Z + {}_{1}^{0}n + \text{energy} \)

fusion reaction

fission reaction

Chain reaction

radioactive decay

View Answer

Question 10 Report

The energy needed to move a unit positive charge around a complete electric circuit is called the

electromotive force

electric potential difference

electric energy

kinetic energy

Heat Energy

Properties Of Waves: Reflection, Refraction, Diffraction

Introductory Electronics

View Answer

Question 11 Report

A 20kg mass is to be pulled up a slope inclined at 300 to the horizontal. If efficiency of the plane is 75%. The force required to pull the load up the plane is J [g=10ms\(^{-2}\)]

87N

73.5N

133.3N

533.2N

Gravitational Field

View Answer

Question 12 Report

What effort will a machine of efficiency 90% apply to a load of 180N if its efforts arm is twice as long as its load arm?

100N

90N

80N

120N

Simple Machines

View Answer

Question 13 Report

If the fraction of the atoms of a radioactive material left after 120years is \( \frac{1}{64} \), what is the half-life of the material? \( \frac{1}{64} \)

20 years

10 years

2 years

24 years

Work, Energy And Power

View Answer

Question 14 Report

An object moves in a circular path of radius 0.5m with a speed of \(1ms^{-1}\). What is its angular velocity?

8rads

^{- 1}

4rads

^{- 1}

1rads

^{- 1}

2rads

^{- 1}

Motion

Speed And Velocity

View Answer

Question 15 Report

In the diagram given the hanging mass m2 is adjusted until m1 is on the verge of sliding. The coefficient of static

m₁

m₂

m₁	g
m₂

m₂

m₁

m₂	g
m₁

Answer Details

I think the correct option is C (

\frac{m_{2}}{m_{1}}

). The coefficient of friction is a ratio of two forces and hence g will cancel out.

Read lesson note on Liquids At Rest (JAMB)

Liquids At Rest

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Question 16 Report

A positively charged rod X is brought near an uncharged metal sphere Y and is then touched by a finger with X still in place. When the finger is removed, the result is that Y has

no charge and a zero potential

a positive charge and a zero potential

a negative charge and a positive potential

a negative charge and a negative potential

Electrostatics

View Answer

Question 17 Report

The density of 400cm3 of palm oil was 0.9gcm-3 before frying. If the density of the oil was 0.6gcm-3 after frying, assuming no loss of oil due to spilling, its new volume was?

1360cm

^{3}

600cm

^{3}

240cm

^{3}

8000m

^{3}

View Answer

Question 18 Report

Cathode rays are

High-energy electromagnetic waves

protons

neutrons

streams of electrons

Electric Field

Electromagnetic Field (Part 2)

View Answer

Question 19 Report

A 40W instrument has a resistance 90 Ohms. On what voltage should it be operated normally

60V

150V

225V

360V

Current Electricity

Simple A.C Circuits

View Answer

Question 20 Report

Calculate the effective capacitance of the circuit in the diagram given

4μf

3μf

2μf

1μf

View Answer

Question 21 Report

Which of the following may be used to explain a mirage?

I. Layers of air near the road surface have varying refractive indices in hot weather

II. Road surfaces sometimes become good reflectors in hot weather

III. Light from the sky can be reflected upwards after coming close to the road surface.

I and III only

II and III only

II only

I, II and III

Reflection Of Light At Plane And Curved Surfaces

View Answer

Question 22 Report

What flows to the earth by connecting the conductor to the earth?

Electrons

Ion

Neutron

Proton

Electrostatics

View Answer

Question 23 Report

The pitch of an acoustic device can be increased by

decreasing the loudness

increasing the intensity

increasing the frequency

decreasing the intensity

Current Electricity

Sound Waves

View Answer

Question 24 Report

In the diagram given if the atmospheric pressure is 760mm, the pressure in the chamber G Is

660mm

890mm

690mm

860mm

Pressure

View Answer

Question 25 Report

The linear expansivity of brass is \(2 \times 10^{-5}\,\text{C}^{-1}\). If the volume of a piece of brass is 15.00cm at 0°C, what is the volume at 100°C

16.03cm

^{3}

15.09cm

^{3}

16.00cm

^{3}

15.03cm

^{3}

Thermal Expansion

View Answer

Question 26 Report

A boy receives the echo of his clap reflected by a nearby hill 0.8s later. If the speed of sound in air is 3.40ms\(^{-1}\), how far is he from the hill?

66m

136m

264m

528m

View Answer

Question 27 Report

The diagram shown represents a block-and-tackle pulley system on which an effort of W Newtons supports a load of 120.0N. If the efficiency of the machine is 40, then the value of W is?

28.0

48.0N

233.0N

50.0N

Answer Details

Let the total number of pulleys used in both the blocks be

n

.
In a block-and-tackle pulley system, the velocity ratio is equal to n.
Efficiency =

\frac{MA}{VR} \times 100 %

MA = \frac{L}{E}, VR = n

Efficiency =

\frac{L}{E} \times \frac{1}{n} \times 100 %

E = \frac{L}{Eff. \times n} \times 100 %

E = \frac{120 N}{40 % \times 6} \times 100 %

E = 50 N

Read lesson note on Simple Machines (JAMB)

Simple Machines

View Answer

Question 28 Report

Temperature is the property of a body which is proportional to the ____.

total kinetic energy of its molecules

average kinetic energy of its molecules

average speed of its molecules

maximum speed of its molecules

Temperature And Its Measurement

View Answer

Question 29 Report

Palm oil from a bottle flows out more easily after it has been heated because the

Molecules are given energy during the heating

Friction between oil layers is reduced

Oil molecules force each other out

Adhesion between the oil molecules and those of the bottle is increased

Thermal Expansion

Structure Of Matter And Kinetic Theory

View Answer

Question 30 Report

The differences observed in solids, liquids and gases may be accounted for by

their relative masses

their melting points

the spacing and forces acting between the molecules

the different molecules in each of them

Thermal Expansion

Structure Of Matter And Kinetic Theory

View Answer

Question 31 Report

Which of the following phenomena cannot be explained by the molecular theory of matter?

Conduction

Convection

Expansion

Radiation

Thermal Expansion

View Answer

Question 32 Report

A lead bullet of mass 0.05 kg is fired with a velocity of 200 ms into a lead block of mass 0.95 kg. Given that the lead block can move freely. the final kinetic energy after impact is

100J

150J

50J

200J

View Answer

Question 33 Report

A solid cube of side 50cm and mass 75kg floats in a liquid with \( \frac{1}{3} \) of its height above the liquid surface. The relative density of the liquid is?

0.33

0.50

0.67

0.90

Answer Details

Volume of liquid displaced
=

\frac{2}{3}

(0.5)

^{3}

Mass of liquid displaced = mass of floating cube = 75kg
Density of liquid =

\frac{m a s s}{v o l u m e}

=

\frac{75}{(\frac{7}{3 (0.5)})}

× 3
= 0.9 × 103kgm

^{- 3}

R.D of liquid =

\frac{(0.9)}{(1.0)}

× 103
= 0.9

View Answer

Question 34 Report

Which of the following is not a product of nuclear fusion?

X – ray

Y –ray

α – particles

neutron

Magnetic Field (Part 2)

Electromagnetic Field (Part 2)

View Answer

Question 35 Report

A solid weighs 45N and 15N respectively in air and water. Determine the relative density of the solid

0.33

0.50

1.50

3.00

Answer Details

The relative density of a substance is defined as the ratio of its density to the density of a reference substance, usually water at 4 degrees Celsius. In this problem, we can use the principle of buoyancy to determine the density of the solid. When an object is submerged in a fluid, it experiences an upward force called the buoyant force, which is equal to the weight of the fluid displaced by the object. If the object is less dense than the fluid, it will float, and if it is more dense, it will sink. We are given that the solid weighs 15 N in water, which means it displaces 15 N of water. The weight of the water displaced is equal to the buoyant force on the solid, which is equal to the weight of the solid when it is completely submerged in water. Therefore, the weight of the solid when it is completely submerged in water is 15 N. We are also given that the weight of the solid in air is 45 N. The difference between the weight of the solid in air and water is equal to the weight of the water displaced, which is 30 N. This means that the volume of water displaced by the solid is 30/9.8 = 3.06 L (since the density of water is 1000 kg/m^3 or 9.8 N/L). The relative density of the solid is equal to its density divided by the density of water. We can find the density of the solid by dividing its weight in air by its volume: Density of solid = Weight of solid in air / Volume of solid Density of solid = 45 N / (45 N - 15 N) [since weight of displaced water is 15N] Density of solid = 45 N / 30 N Density of solid = 1.5 N/L Therefore, the relative density of the solid is: Relative density = Density of solid / Density of water Relative density = 1.5 N/L / 1000 N/L Relative density = 0.0015 So the answer is 0.33 (rounded to two decimal places).

Read lesson note on Equilibrium Of Forces (JAMB)

Read lesson note on Scalars And Vectors (JAMB)

Equilibrium Of Forces

Scalars And Vectors

View Answer

Question 36 Report

Which of the following is an essential physical property of the wires uses for making fuses ?

Low density

Hypothermal conductivity

Low electrical resistivity

Low melting point

Gravitational Field

Electrostatics

View Answer

Question 37 Report

Which of the following is the dimension of pressure

ML

^{- 1}

T

^{- 2}

MLT

^{- 2}

ML

^{2}

T

^{3}

ML

^{- 3}

View Answer

Question 38 Report

Which of the following statements are TRUE of isotopes?

I. Isotopes of an element have the same chemical properties because they have the same number of electrons

II. Isotopes of elements are normally separated using physical properties

III. Isotopes of an element have the same number of protons in their nuclei

I and II only

I and III only

II and III only

I, II and III

Structure Of The Atom (Nigeria Only)

View Answer

Question 39 Report

The product of force and time is?

Impulse

Momentum

Inertia

Friction

Work, Energy And Power

View Answer

Question 40 Report

In a series R-L-C circuit at resonance, the voltages across the resistor and the inductor are 30V and 40V respectively. What is the voltage across the capacitor?

30V

70V

50V

40V

View Answer






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