2015 - JAMB Physics Past Questions and Answers - page 3

A radio waves is an electromagnetic waves which travels with a constant velocity of 3 × 10⁸m/s

( \theta1 = 35°C T1 = 273 + θ = 73 + 35 = 308k P1 = 5 )atm

d1 = 0.600g/ litre

θ₂ = 350°C, T2 = 2 + 3 + θ

= 273 + 350 = 623k, d2 = ?

P2 = 7atm

T a P a 1/d = TPK/d (where k is a constant)

Tp1 ÷ d1 = T1P2 ÷ d2, [(308 × 5) ÷ 0.600]

= (623 × 7) ÷ d2

d2 = (623 × 7 ×0.600) ÷ (308 × 5)

= 2616.6 ÷ 1540

= 1.69g / litresd2 = 1.69g / litres

∴ d2 = 1.70g / litres (Approx.)

The vibrating particles behave like a spiral spring with a series of compression region and space–out region.

Work (w) = Force (f) × Distance (d)

Note: f = ma = mass × acceleration

= mass ×acceleration ×distance

= kg ×ms^–2 × m

= kg m2 5^–2

(Note: the dimension of kg = M, M = L & S = T)

Work = ML2 T–2 = Ma Lb Tc

i.e. Ma Lb Tc = as 1, b = 2, c = –2

The value of a, band c = 1, 2, –2

Magnetic relay device :is the device that controls a circuit (i.e one circuit )if a current in the second circuit is large or dangerous

Conduction, conveying of heat or electricity through a material medium is required

Calorimeter is an apparatuses used for measuring the heat (Q) generated or absorbed by change of phase (state) or other physical change

Lodestone is a natural magnet it points approximate at N – S when suspended freely

Infrared rays are easily detected by special photographic films and it can be used for taking picture in haze

From S = ut + ½gt²

u = 0ms^-1

50 = (0 × t) + ½(10)(t²)

50 = 5.0t²

t² =50/5

t = √10

t = 3.2sec