Physics 2014 JAMB Past Questions

1. What is the least possible error encountered when taking measurement with a meter rule?

A. 0.1mm
B. 1.0mm
C. 0.5mm
D. 0.2mm

Correct Answer: Option C

2. A quantity which requires magnitude and direction to be specified is

A. Temperature
B. Distance
C. Displacement
D. Mass

Correct Answer: Option C

Explanation

Displacement is a vector quantity

3. I Electrical potential, II Torque, III Kinetic Energy, IV Momentum. Which of the quantities listed are vectors?

A. II and IV
B. I and II
C. I and III
D. II and III

Correct Answer: Option A

4. Which type of motion do the wheels of a moving car undergo?

A. Vibratory and translational motion
B. Random and translational motion
C. Rotational mand oscillatory motion
D. Translational and rotational motion

Correct Answer: Option D

Explanation

The tyre in motion makes a rotation and it translates in a straight line alongside. if the wheels is turned it continued further in a translational straight line through rotational motion.

5. A car accelerates uniformly from rest at 3ms^-2. its velocity after traveling a distance of 24m is

A. 12ms^-1
B. 144ms^-1
C. 72ms^-1
D. 36ms

Correct Answer: Option A

Explanation

V² = U² x 2ax
V² = 0 x 2(3)(24)
V² = 144
V =

\sqrt{144}

V = 12ms^-1

6. Calculate the escape velocity of a satellite launched from the earth's surface if the radius of the earth is 6.4x10⁶m

A. 25.3kms^-1
B. 4.2kms^-1
C. 4.0kms^-1
D. 11.3kms^-1

Correct Answer: Option D

Explanation

V_escape =

\sqrt{2 g R}

V_escape =

\sqrt{2 \times 10 \times 6.4 \times 10^{6}}

V_escape =

\sqrt{128000000}

V_escape = 11313.7085mS^-1
V_escape = 11.313kmS^-1

7. An object of weight 80kg on earth is taken to a planet where acceleration due to gravity is one-third of its value on earth. The weight of the object on the planet is

A. 48N
B. 12N
C. 27N
D. 36N

Correct Answer: Option C

8. One of the conditions necessary for an object to be in equilibrium when acted upon by a number of parallel forces is that the vector sum of the forces is

A. Average
B. Zero
C. Negative
D. Positive

Correct Answer: Option D

Explanation

Conditions for non-parallel coplanar forces

9. What happens when three coplanar non-parallel forces are in equilibrium?

A. Their lines of action are parallel.
B. They are represented in magnitude only
C. They are represented in direction only
D. Their lines of action meet at a point

Correct Answer: Option D

Explanation

Conditions for non-parallel coplanar forces

10. An object of mass 20kg is released from a height of 10m above the ground level. The kinetic energy of the object just before it hits the ground is

A. 200J
B. 4000J
C. 2000J
D. 500J

Correct Answer: Option C

Explanation

Kinetic Energy = mgh
= 20 x 10 x 10 J
= 2000J

11. The energy in the nucleus of atoms produce heat which can be used to generate

A. Kinetic energy
B. Mechanical energy
C. Electrical energy
D. Potential energy

Correct Answer: Option A

12. A machine whose efficiency is 75% is used to lift a load of 1000N. Calculate the effort put in to the machine if it has a Velocity ratio of 4.

A. 343.32N
B. 233.33N
C. 333.33N
D. 334.33N

Correct Answer: Option C

Explanation

\frac{M A}{V R} \times \frac{100}{1} = e f f i c i e n c y

\frac{L}{E} \frac{1}{V R} \times \frac{100}{1} = 75

\frac{1000}{E} \frac{1}{4} \times \frac{100}{1} = 75

E = \frac{250 \times 100}{75}

E = 333.3N

13. A wheel and an axle is used to raise a load whose weight is 800N when an effort of 250N is applied. If the radii of the wheel and axle are 800mm and 200mm respectively, the efficiency of the machine is

A. 90%
B. 80%
C. 85%
D. 87%

Correct Answer: Option B

Explanation

VR = 800/200 = 4

E f f i c i e n c y = \frac{M A}{V R} \times \frac{100}{1}

E f f i c i e n c y = \frac{L}{E} \times \frac{1}{V R} \times \frac{100}{1}

E f f i c i e n c y = \frac{800}{250} \times \frac{1}{4} \times \frac{100}{1}

= 78.74%
= 80%

14. A force of 500N¹ is applied to a steel wire of cross-sectional area 0.2m², The tensile stress is

A. 2.5x10⁴Nm^-2
B. 1.0x10²Nm^-2
C. 1.0x10³Nm^-2
D. 2.5x10³Nm^-2

Correct Answer: Option D

Explanation

S t r e s s = \frac{F o r c e}{A r e a}

S t r e s s = \frac{500}{0.2} = 2500

= 2.5 x 10³Nm^-3

15. The small droplets of water that form on the grass in the early hours of the morning is

A. Fog
B. Haul
C. Mist
D. Dew

Correct Answer: Option D

16. What is the equivalent of 20K in Celsius scale?

A. -253^oC
B. -293^oC
C. 68^oC
D. 36^oC

Correct Answer: Option A

Explanation

= (20 - 273)°C
= -253°C

17. The equation P^aV^bT^c= constant reduces to Charles Law if

A. a=1, b=1and c=0
B. a=1, b=0 and c=-1
C. a=0, b=1 and c=1
D. a=0, b=1 and c=-1

Correct Answer: Option D

Explanation

if a=0, b=1 and c=-1 then
P⁰V¹T^-1 = V/T (Charles Law)

18. The quantity of heat needed to raise the temperature of a body by 1K is the body's

A. Heat capacity
B. Internal energy
C. Specific heat capacity
D. Latent heat of fusion

Correct Answer: Option A

19. The melting point of a substance is equivalent to its

A. Vapour Pressure
B. Solidification Temperature
C. Liquidification Temperature
D. Solidification Pressures

Correct Answer: Option B

20. The temperature at which the water vapour present in the air is just sufficient to saturate air is

A. Boiling point
B. Ice point
C. Saturation point
D. Dew point

Correct Answer: Option D

21 Heat transfer by convection in a liquid is due to the

A. Latent heat of vaporization of the liquid
B. Increased vibration of the molecules of the liquid about theit mean position
C. Variation of density of the liquid
D. Expansion of the liquid as it is heated

Correct Answer: Option D

Explanation

Liquids and gases expand when they are heated. The liquid or gas in hot areas is less dense than the liquid or gas in cold areas, so it rises into the cold areas.

22.The distance between two successive crests of a wave is 15cm and the velocity 300ms^-1. Calculate the frequency.

A. 2.0x10²Hz
B. 4.5x10³Hz
C. 2.0x10³Hz
D. 4.5x10²Hz

Correct Answer: Option C

Explanation

Wavelength = 15cm = 0.15m

Velocity = 300m/s

V = fx

F = V/Wavelength

F = 300/0.15 Hertz

F = 2 x 10³Hz

23. A boy receives the echo of his clap reflected by a nearby hill 0.8s later. How far is he from the hill?

A. 528m
B. 66m
C. 136m
D. 264m

Correct Answer: Option C

Explanation

Time for echo both ways = 0.8
Therefore time for echo in 1 way = 0.8/2 = 0.4

Distance = Speed x time

Distance = 340 x 0.4

Distance = 136m

24. An object is placed 10m from a pinhole camera of length 25cm. Calculate the linear magnification.

A. 2.5x10²
B. 2.5x10^-2
C. 2.5x10^-1
D. 2.5x10¹

Correct Answer: Option B

Explanation

Linear Magnification = \frac{Length of Camera}{Distance of the Object}

Linear Magnification = \frac{25}{1000}

Linear Magnification = 2.5 \times 10^{- 2}

25. The focal length of a concave mirror is 2.0cm. If an object is placed 8.0cm from it, the image is at

A. 2.7m
B. 2.0m
C. 2.3m
D. 2.5m

Correct Answer: Option A

Explanation

\frac{1}{U} + \frac{1}{V} = \frac{1}{f}

\frac{1}{8} + \frac{1}{V} = \frac{1}{2}

V = \frac{8}{3}

V = 2.7 c m