Physics 1997 Jamb Past Questions and Answers

Question 21 :

• JAMB 1997

A heating coil rated at 100W is used to boil off 0.5kg of boiling water. The time taken to boil off the water is [specific latent heat of vaporization of water = 2.3 x 10⁶Jkg^-1]

A. 1.15 x 10⁹ s
B. 1.15 x 10⁷ s
C. 1.15 x 10⁵ s
D. 1.15 x 10⁴ s

Question 22 :

• JAMB 1997

A mass of a liquid at 30^oC is mixed with a mass of the same liquid at 70^oC and the temperature of the mixture is 45^oC. Find the ratio of the mass of the cold liquid to the mass of the other liquid.

A. 3 : 5
B. 5 : 3
C. 3 : 7
D. 7 : 3

Question 23 :

• JAMB 1997

What happens when a gas expands at constant temperature?

A. Its pressure decreases
B. The total momentum of its molecules remains constant
C. Its pressure decreases and the total momentum of its moleculees remains constant
D. Its pressure decreses and the total kinetic energy of its molecule decreases

Question 24 :

• JAMB 1997

Ripples on water and light waves are similar because both

A. Have the same frequency
B. Can be refracted and diffracted
C. Are longitudinal waves
D. Have the same velocity

Question 25 :

• JAMB 1997

Under constant tension and constant mass per unit length, the note produced by a plucked string is 500Hz when the length of the string is 0.90m. At what length is the frequency 150Hz?

A. 3m
B. 4m
C. 5m
D. 6m