Post Utme Physics Past Questions and Answers

Question 151:

A parachute attains terminal velocity when ____________

A. Its density is equal to the density of air
B. The Viscous force of air and up thrust completely counteract its weight
C. It expands as a result of reduced external pressure
D. The viscous force of the air is equal to the sum of the weight and upthrust

Question 152:

An electrical heater is used to melt a block of ice, mass \(1.5 \mathrm{~kg}\), If the heater is powered by a \(12 \mathrm{~V}\) battery, and a current of \(20 \mathrm{~A}\) flows through the coil, calculate the time taken to melt the block of ice at \(0^{\circ} \mathrm{C}\). (specific latent heat of fusion of ice \(=336 \times 10^{3} \mathrm{~J} / \mathrm{kg}\) )

A. \(76.0 \min\)
B. \(35.0 \mathrm{~min}\)
C. \(21.0 \mathrm{mn}\)
D. \(2.9 \min\)

Question 153:

\(200 \mathrm{~g}\) of water at \(90^{\circ} \mathrm{C}\) is mixed with same quantity of water at \(30^{\circ} \mathrm{C}\).

What is the final temperature?

A. \(50^{\circ} \mathrm{C}\)
B. \(60^{\circ} \mathrm{C}\)
C. \(70^{\circ} \mathrm{C}\)
D. \(80^{\circ} \mathrm{C}\)

Question 154:

The equation \(P^{x} V^{y} T^{z}=\) constant is Charles law when ____________

A. \(x=1, y=1, z=1\)
B. \(x=0, y=1, z=1\)
C. \(x=1, y=0, z=1\)
D. \(x=0, y=1, z=1\)

Question 155:

For short-sighted person, light rays from a point on a very distant object is focused ____________

A. In front of the retina
B. Behind the-retina
C. Behind the retina by a diverging lens
D. In front of the, retina a distance \(2 F\) from the lens