2006 - WAEC Physics Past Questions and Answers - page 3
The silvered surface in a vacuum flask reduces heat loos due to
How long will it take to heat 3kg of water from 28oC to 88oC in an electric kettle taking 6a from a 220V supply? [specific heat capacity of water = 4180 J kg-1K-1]
The amount of energy required to change a kilogram of ice in water without a change in temperature is
A quantity of steam at 100oC condenses to water at the same temperature by releasing 6.9 x 104J of energy. Calculate the mass of the condensed steam. [specific latent heat of vaporization of eater = 2.3 x 106 J kg-1]
The temperature of a liquid falls after some of it has evaporated because
The S.I units of frequency, period and amplitude of a wave are respectively
a note of frequency 2000Hz has a velocity of 400 ms-1. calculate the wavelength of the note
The eclipse of the moon occurs when the
Which of the following observations cannot be explained using the rectilinear propagation of light?
The distance between the successive crests of a wave travelling at 20ms-1 is 25cm. Calculate the frequency of the wave