2011 - JAMB Physics Past Questions and Answers - page 2

Efficiency = ( \frac{\text{work output}}{\text{work input}} \times \frac{100}{1} )

= 40 = ( \frac{20 \times 10 }{x} \times \frac{100}{1} )

= 500J

Pressure in liquid is independent of cross sectional area of the container/ liquid

∴ the correct options are I & II

grease is more viscous than the rest of the liquids

Sound is the only mechanical wave among the rest which are electromagnetic waves.

r - rays has the highest frequency followed by X - rays, ultraviolet ray, visible light intra - red and the least is radio weaves

Dull, black surface are good emitters or absorbers of energy

The earth radiate heat to the atmosphere at night thereby lowering the temperature of the ground

V = (2X)/t

330 = (2 x 4.95 x 10³)/t

t = (9.9. x 10³/330 = (9900)/330 = (90)/3

= 30 secs

Regelation means refreezing a phenomenon whereby melted ice free from increased pressure refreezed when they are released from the pressure.

Heat supplied = Heat gained Pt = MCDθ

30 x 5 x 60 = c x 10

where c = mc which is the heat capacity

c = (30 x 5 x60)/10 = 900 JKg^-1