JAMB Physics Past Questions & Answers - Page 8

W =  mg  = 220 x 9.8 = 2156 N

⇒Sin 38º = \(\frac{2156}{T_1}\)

⇒ \(T_1\) =    \(\frac{2156}{Sin 38}\)

⇒ \(T_1\) =     3502 N

Cos 38º =  \(\frac{T_2}{T_1}\)

⇒ \(T_2\)  =   3502 x Cos 38º

⇒ \(T_2\) =   2760 N

;    \(T_1\) =   3502 N,  \(T_2\) = 2760 N.

Electrical conduction of gas is applied in:
(i) The identification of gases
(ii) Lighting/fluorescent tubes
(iii) Advertising industry/Neon signs
(iv) Cathode ray oscilloscope/T.V. tubes

Diffraction is the bending of waves around the corners of an obstacle or through an aperture.

A body sliding down a plane inclined at 30o to the horizontal,

Has coefficient of friction = tan 30º  or \(\frac{1}{√3}\)

The height of the mercury column serves as an indicator of atmospheric pressure. At sea level and at a temperature of 0° Celsius (C), the height of the mercury column is approximately 30 inches, or 76 centimeters. This represents a pressure of approximately 14.7 psia. The 30-inch column is used as a reference standard.

Examples of scalar quantities are mass, energy, distance, charge, volume, time, speed, and the magnitude of physical vectors in general

It's generally created using silicon, germanium, or other pure elements.

Semiconductors are created by adding impurities to the element.

The conductance or inductance of the element depends on the type and intensity of the added impurities.

The electrons surrounding each atom in a semiconductor are part of a covalent bond

Factors Affecting The Speed of Sound

• The Density of Medium: Sound requires a medium to travel. The density of the medium is among the factors which affect the speed of sound. ...
• The Temperature of The Medium: Higher the temperature, the higher is the speed of sound in the medium.

where force = f, mass = m, acceleration = a, velocity = v, time = t

Force = m * a → m * \(\frac{Δv}{t}\) 

Power = f * v

P = m * \(\frac{v}{t}\)  * v = m * \(\frac{v^2}{t}\) 

p =  \(\frac{1600 * 25^2}{20}\) 

p = 50,000 or 50 KW

quantity of heat = mass * Specific latent heat → 20 * 336 

quantity of heat = 6720j or  6.72 x 10\(^{3}\)J