2022 - JAMB Physics Past Questions and Answers - page 4

Specific latent heat of fusion of a substance is the quantity of heat required to convert the unit mass of the substance from the solid to the liquid state without a change in temperature.

Magnetic flux is a measurement of the total magnetic field which passes through a given area. 

Mathematically, it is the surface integral of the normal component of the magnetic field (B) passing through that surface.

Magnetic force is often denoted Φ or ΦB, with the SI unit Weber

B = Φ/A

Where:
B is magnetic flux density in teslas (T)
Φ is magnetic flux in webers (Wb)
A is area in square meters (m2).

The graph of pressure (P) against the reciprocal of the volume (I/V) is a straight line passing through the origin.

Quantity of heat = mass * specific latent heat 

=> 20 * 336 

Quantity of heat = 6720j

= 6.72 x 10\(^{3}\)J

Let:
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

Factors affecting the speed of sound include:

• Nature of material/medium: Sound travels faster in liquids than in gases and faster in solids than in liquids.
• The density of the 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 the speed of sound in the medium.

Semiconductors are generally formed from silicon, germanium, or other pure elements, by adding impurities to the element.

Vector quantities have magnitude and direction. Scalar quantities have only a magnitude.

Examples of vector quantities:

• weight
• displacement
• acceleration
• force
• momentum

Examples of scalar quantities:

• distance
• mass
• speed
• energy
• time
• volume

A body sliding down a plane inclined at 30º to the horizontal has coefficient of friction = tan 30º 

=> \(\frac{1}{√3}\)