Physics Past Questions and Answers

A man stands 4m in front of a plane mirror. If the mirror is moved 1m towards the man, the distance between him and his new image is?

A 3m
B 5m
C 6m
D 10m

Question 4127:

The temperature gradient across a copper rod of thickness 0.02m, maintained at two temperature junctions of 20º and 80ºC respectively is?

A 3.0 x 10\(^{2}\)km\(^{-1}\)
B 3.0 x 10\(^{3}\)km\(^{-1}\)
C 5.0 x 10\(^{3}\)km\(^{-1}\)
D 3.0 x 10\(^{4}\)km\(^{-1}\)

Question 4128:

Calculate the mass of ice that would melt when 2kg of copper is quickly transferred from boiling water to a block of ice without heat loss (specific heat capacity of copper = 400Jkg\(^{1}\)k\(^{-1}\), latent heat of fusion of ice = 3.3 x 10\(^{5}\)Jkg\(^{-1}\))

A \(\frac{8}{33}\)kg
B \(\frac{3.3}{80}\)kg
C \(\frac{80}{33}\)kg
D \(\frac{3.3}{8}\)kg

Question 4129:

The equation of a wave traveling along the positive x-direction is given by; y = 0.25 x 10\(^{-3}\) sin (500t - 0.025x). Determine the angular velocity of the wave motion.

A 0.25 x 10\(^{-3}\)rads\(^{-1}\)
B 0.25 x 10\(^{-1}\)rads\(^{-1}\)
C 5.00 x 10\(^{2}\)rads\(^{-1}\)
D 2.50 x 10\(^{3}\)rads\(^{-1}\)

Question 4130:

If a sound wave goes from a cold air region to a hot air region, its wavelength will?

A Increase
B Decrease
C Decrease then increase
D Remain constant