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 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

High-energy electromagnetic waves

JAMB UTME - Physics - 2018 | Green Bridge CBT

Question 1 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 2 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 3 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 4 Report

For what values of F and ? will the forces shown in the diagram below be in equilibrium.

60N and 60

^{o}

60N and 30

^{o}

20?3 N and 60

^{o}

20?3N and 30

^{o}

Answer Details

Resolve vertically, 40cos? = 20, ? = 60

^{o}

Resolve horizontally, f = 40sin? = 40sin60

^{o}

= 40(

\frac{\sqrt{3}}{2}

)
= 20?3 N

Read lesson note on Equilibrium Of Forces (WAEC)

Equilibrium Of Forces

View Answer

Question 5 Report

Electrical power is transmitted at a high voltage rather than a low voltage because the amount of energy loss is due to

Heat dissipation

Production of eddy currents

Excessive current discharge

Excessive voltage discharge

View Answer

Question 6 Report

Shadows and eclipses result from the

refraction of light

reflection of light

defraction of light

rectilinear propagation of light

Answer Details

The rectilinear propagation of light means that light travels in straight lines as a wave. This can be observed in the well-defined shadows formed when an object blocks a light source and through the use of a pinhole camera.
According to Sudipa Sarkar, the formation of shadows with sharp edges demonstrates the rectilinear propagation of light, i.e. The fact that light travels in straight line. When an opaque obstacle is placed between a source of light and a screen, a shadow of the obstacle is formed on the screen. The kind of shadow depends on the size of the source of light. If it is a point source (light from a small hole), the shadow obtained is a region of total darkness, called umbra.
If an extended source of light, e.g. a bulb, is used, the umbra is surrounded by a region of partial darkness, called penumbra. The moon is seen because it reflects the sun's light. An eclipse of the moon (lunar eclipse) occurs when the earth comes between the sun and the moon and prevents some of the light from the sun from reaching the moon. In other words, the earth casts its shadow on the moon. The solar eclipse occurs when the moon comes between the sun and the earth.

Read lesson note on Reflection Of Light At Plane And Curved Surfaces (JAMB)

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

Read lesson note on Types Of Waves (WAEC)

Reflection Of Light At Plane And Curved Surfaces

Properties Of Waves: Reflection, Refraction, Diffraction

Types Of Waves

View Answer

Question 7 Report

An electric heating coil rated at 1KW is used to heat 2kg of water for 2 minutes. The initial water temperature is 30\(^{o}\)C. Taking the specific heat of the water as 4,000Jkg\(^{-1}\) and neglecting that of the container, the final water temperature is

15.0

^{o}

C

45.0

^{o}

C

52.5

^{o}

C

25.0

^{o}

C

Quantity Of Heat

View Answer

Question 8 Report

Calculate the effective capacitance of the circuit in the diagram given

4μf

3μf

2μf

1μf

View Answer

Question 9 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 10 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 11 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

View Answer

Question 12 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

Question 13 Report

A man walks 1km due east and then 1 km due north. His displacement is

√2km N 45°E

1km N 30°E

1km N 15°E

√2km N 60°E

Scalars And Vectors

Position, Distance And Displacement

View Answer

Question 14 Report

Which of the following has the lowest internal resistance when new?

Leclanche cell

Daniell cell

Torch battery

Accumulator

Answer Details

Among the given options, the Accumulator has the lowest internal resistance when new. Internal resistance is the resistance that a battery or cell provides to the flow of electric current within itself. Lower internal resistance means that the battery can supply more current to an external circuit without losing much of its own energy as heat. An Accumulator, also known as a rechargeable battery, is designed to be charged and discharged multiple times. It has a relatively low internal resistance when new, meaning it can provide a higher current than the other cells listed while wasting less energy internally as heat. A Leclanche cell and Daniell cell are primary cells, meaning they are designed to be used once and discarded. They have higher internal resistance compared to the accumulator, which limits their ability to supply high currents. A Torch battery, also known as a dry cell, is also a primary cell and has a higher internal resistance than the accumulator. It is commonly used in small electronic devices and has a longer shelf life than Leclanche and Daniell cells. In summary, an Accumulator has the lowest internal resistance when new, which makes it an ideal choice for applications requiring high current delivery such as electric vehicles, power tools, and renewable energy systems.

Read lesson note on Current Electricity (JAMB)

Read lesson note on Electric Cells (JAMB)

Read lesson note on Gravitational Field (JAMB)

Current Electricity

Electric Cells

Gravitational Field

View Answer

Question 15 Report

Which of the following phenomena is the practical evidence for the existence of the continual motion of molecules.

Transitional Motion

Rotational Motion

Brownian Motion

Oscillatory Motion

Thermal Expansion

Structure Of Matter And Kinetic Theory

View Answer

Question 16 Report

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

temperature of its surroundings

temperature of the body

difference in temperature between the body and its surroundings

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

Heat Energy

View Answer

Question 17 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 18 Report

The tendency of a body to remain at rest when a force is applied to it is called.

Impulse

Momentum

Inertia

Friction

Scalars And Vectors

Equilibrium Of Forces

View Answer

Question 19 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 20 Report

The friction which exist between two layers of liquid in relative motion is called

Capillary

Surface

Viscosity

Cohesion

Friction

Properties Of Waves: Reflection, Refraction, Diffraction

View Answer

Question 21 Report

In the diagram shown, If the south-poles of two magnets stroke a steel bar, the polarities at T and V will respectively be

north and south

south and south

north and north

south and north

Magnets And Magnetic Fields

View Answer

Question 22 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 23 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 24 Report

Which of the following obeys Ohm's law?

all metals

diode only

all electrolytes

glass

Electrostatics

View Answer

Question 25 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 26 Report

If the focal length of a camera is 20cm, the distance from the film at which the lens must be set to produce a sharp image of 100cm away is

17cm

20cm

25cm

100cm

Answer Details

F = 20cm
V = 100cm
U = ?

\frac{1}{U}

+

\frac{1}{V}

=

\frac{1}{F}

\frac{1}{20}

+

\frac{1}{100}

=

\frac{1}{F}

\frac{5 + 1}{100}

=

\frac{1}{F}

F =

\frac{100}{6}

= 16.7cm
= 17cm

Read lesson note on Vapours (JAMB)

Vapours

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Question 27 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 28 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 29 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 30 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 31 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 32 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 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

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 35 Report

The electrochemical equivalent of silver is 0.0012g/C. If 36.0g of silver is to be deposited by electrolysis on a surface by passing a steady current for 5mins, the current must be?

6000A

100A

10A

1A