Physics Past Questions and Answers

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

A 1200cm³
B 1378cm³
C 4320cm³
D 4629cm³

Question 12:

An electric heater is used to melt a block of ice of mass 1.5kg. If the heater is powered by a 12V battery and a current of 20A flows through the coil, calculate the time taken to melt the block of ice at 0^oC. [specific latent heat of fusion of ice = 336 x 10³Jkg^-1]

A 76.0min
B 35.0min
C 21.0min
D 2.9min

Question 13:

From the kinetic theory of gases, temperature is a

A Form of energy and is proportional to the total kinetic energy of the molecules
B Form of energy and is proportional to the average kinetic energy of the molecules
C Physical property and is proportional to the total kinetic energy of the molecules
D Physical property and is proportional to the average kinetic energy of the molecules

Question 14:

A vibrator of frequency 60Hz is used in generating transverse stationary waves in a long thin wire, If the average distance between successive nodes on the wire is 45cm, find the speed of the transverse waves in the wire.

A 27ms^-1
B 54ms^-1
C 90ms^-1
D 108ms^-1

Question 15:

When the tension in a sonometer wire is doubled, the ratio of the new frequency to the initial frequency is

A \(\frac{1}{\sqrt2}\)
B \(\frac{1}{2}\)
C \(\sqrt2\)
D 2