2021 JAMB Physics Past Questions CBT

A body of mass 10 kg rests on a rough inclined plane whose angle of tilt is variable, this is gradually increased until the body starts to slide down the plane at 30^o. The coefficient of limiting friction between the body and the plane is

An inclined plane which makes an angle of 30º with the horizontal has a velocity ratio of

What is the length of the liquid column in a barometer tube that would support an atmospheric pressure of 102000 Nm^-2 if the density of the liquid is 2600 kgm^-3? [g = 10 ms^-2]

40 m³ of liquid P is mixed with 60 m³ of another liquid Q. If the densities of P and Q are 1.00 kg/m³ and 1.6 kg/m³ respectively, what is the density of the mixture?

The resistances of a platinum wire at the ice and steam points are 0.75 ohm and 1.05 ohm respectively. Determine the temperature at which the resistance of the wire is 0.90 ohm.

Which of the following statements supports the assumption that light travels in straight lines?

If an object is placed in front of two mirrors inclined at 90º,  how many images will be formed?

An object 3.0 cm high is placed 60.0 cm from a converging lens whose focal length is 20.0 cm. Calculate the size of the image formed.

A pool of water appears to be 1.0 m deep when viewed vertically from above. If the refractive index of water is 1.33, what is the actual depth of the pool?

A ray of light is incident at an angle of 30° on the top surface of a parallel-sided glass block of refractive index 1.5. The ray finally emerges from the lower surface. What is the angular deviation of the emergent ray?

Four lenses are being considered for use as a microscope objective. Which of the following focal lengths is most suitable?

A heavy object is suspended from a string and lowered into water so that it is completely submerged. The object appears lighter because

Which of the following is a derived unit?

Two objects, one having three times the mass of the other, are dropped at the same time from a tall building. When they are above the ground, the two objects will have the same

Which of the following is in a neutral equilibrium?

A ball is thrown vertically into the air with an initial velocity u. What is the greatest height reached?

Which of the following assumptions is made in a simple pendulum experiment? The

Mercury is suitable as a barometric fluid because it

Which of the following properties makes metals ideal for cooking utensils?

A gas occupies a volume of 300 cm³ at a temperature of 27º C. What is its volume at 54ºC, when the pressure is constant?

When two objects, P and Q, are supplied with the same quantity of heat, the temperature change in P is observed to be twice that of Q. If the masses of P and Q are the same, the ratio of the specific heat capacity of P to Q is

Which of the following is true of sound?

A piece of wood of mass 40 g and uniform cross-sectional area of 2 cm floats upright in water. The length of the wood immersed is

The pressure on the gas of a constant gas thermometer at the ice point is 325 mm of mercury and at the steam point, 875 mm of mercury. Find the temperature when the pressure of the gas is 490 mm of mercury.

A column of air 10.0 cm long is trapped in a tube at 27º C. What is the length of the column at 100º C?

A mass of gas at 7º C and 70 cm of mercury has a volume of 1200 cm³. Determine its volume at 27º C and pressure of 75 cm of mercury

An electric heater is used to melt a block of ice, mass 1.5 kg. If the heater is powered by a 12 V battery and a current of 20 A flows through the coil, calculate the time taken to melt the block of ice at 0°C.

[specific latent heat of fusion of ice = 336 × 10³ Jkg^-1]

From the kinetic theory of gases, temperature is a

A boy timed 30 oscillations of a certain pendulum thrice and obtained 1 min. 10 s, 1 min. 12 s and 1 min 7 s, respectively. The mean period of oscillation of the pendulum is

Which of the following is TRUE of light and sound waves?

The image in a pin-hole camera is

When a plane mirror at which a ray is incident is rotated through an angle θ, the reflected ray will be rotated through

A trough 12.0 cm deep is filled with water of refractive index \(\frac{4}{3}\). By how much would a coin at the bottom of the trough appear to be displaced when viewed vertically from above the water surface?

In a ray diagram for a thin converging lens, a ray that is not parallel to the optic axis but passes through the optic centre will

Which of the following correctly describes the image of an object, 4 cm from a diverging lens of focal length -12 cm?

Two tuning forks of frequencies 256 Hz and 260Hz are sounded close to each other. What is the frequency of the beats produced?

A boy sits in a train moving with uniform speed on a straight track. If from his outstretched palm he gently tosses a coin vertically upwards, the coin will fall

A body starts from rest and moves with uniform acceleration of 6ms^-2. What distance does it cover in the third second?

A stone Q is thrown with velocity ‘u’ at an angle of 75º to the horizontal. Another stone, R is thrown with the same velocity ‘u’ but at an angle of 15º to the horizontal. The ranges covered by the stones will be

A man weighing 800 N climbs a flight of stairs to a height of 15 m in 12.5 s. What is the man’s average power output?