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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 = X/t 330 = ( 4.95 x 10^3)/t t = (4.95 x 10^3/330 = = 15 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

The specific latent heat of vaporization of steam is 2.1 x 106JKg-1 while the energy required to raise the temperature of a unit mass of water from 0^\circc to 100^\circc = C x Dt = 4200 x 100 = 420000 = 4.2 x 105 JKg-1 ∴ steam possesses greater heat energy per unit mass

No expanded working has been attached for this question yet. The verified answer is Option D.

Eclipse of the sun occurs when the moon which is opaque objects between the sun and the earth

Steel is not easily magnetized and dismagnetized

Hot wire ammeter is used because the heat affect of A C is same as that of DC