2011 - JAMB Physics Past Questions and Answers - page 3

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°c to 100°c = C x Dt = 4200 x 100 = 420000 = 4.2 x 10⁵ JKg^-1

∴ steam possesses greater heat energy per unit mass

Total energy in parred connection is equal to emt of one cell, = 2v but total internal resistance is given by

(1)/r = (1)/r₁ + (1)/r₂ + (1)/r₃ = (1)/2 + (1)/2 + (1)/2 = (3)/2

∴ r = (2)/3 = 0.67Ω

presbyopia is loss of accommodation

Correct Answer: Option E

        The colour which an object presents to the eye is the colour of light it reflects. Red rose flower will therefore absorb any other colour and reflect red. Therefore when viewed in blue light, it has no colur to reflect and will therefore appear black. Although mixture of red light and blue light = magenta . NO correct option.

Dielectric constant = (c)/c_° = (60)/20 = 3

Correct Answer: Option E

        V = - 50, U = 25CM<br />

(1)/r = (1)/v + (1)/u = (1)/-50 + (1)/25 = (1 + 2)/50 = (1)/50 f = +50cm = +0.5m

p = (1)/r = (1)/0.5 = (10)/5 = 2 diopters

The power of a lens is the reciprocal of the focal length in meters. it is expressed in diopters.

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