Physics Quiz

How much ice will a 3 KW heater melt in one minute, given the latent heat of fusion of water is approximately 300 KJ/Kg?

• 1.7 Kg

• 0.6 Kg

• 6 x 10^-4 Kg

When viewing an image of an object reflected in a concave mirror, the image:

• size depends on the position of the object

• is never laterally inverted

• is always in focus

With respect to reflected light on a plane mirror. If the angle between the incident ray and the normal is doubled, the angle between the reflected ray and the normal:

• is halved

• is doubled

• remains the same

Fibre optics utilise the phenomina of total internal:

• defraction

• reflection

• refraction

The effect of loss of depth when looking at a submerged object is due to:

• reflection

• refraction

• fluid viscosity

Parallel rays of light passing through a concave lens will:

• diverge and produce a focus before the lens

• be converged by the lens and produce a focus on the other side

• diverge and produce a real image

If the period of a sine wave is 25 milliseconds, the frequency is:

• 40 kHz

• 40 Hz

• 25 kHz

A sound wave of travelling at a velocity of 450 m/s has a wavelength of 0.25 m. The frequency of the sound wave will be:

• 1,800 Hz

• 112.5 Hz

• 2,250 Hz

The speed of sound travelling through water, compared to air will travel:

• faster

• slower

• at the same speed, but the amplitude will increase