2022 - JAMB Physics Past Questions and Answers - page 1

A derived unit is a unit of measurement in the International System of Units (SI) that is derived from one or more of the seven base units.

Examples of derived units:

• Velocity (m/s)
• Density kg/m3
• Force (Newton)
• Pressure (Pascal)
• Energy (Joule)
• Power (Watt)

We can derive other units from the independent units. The independent units are called Fundamental Units (or Base Units).

Examples of fundamental units are Mass in kilogram (kg); Electric Current, ampere (A); Temperature, kelvin (K); Amount of Substance, mole (Mol).

When a bar magnet is cut into two, the newly cut faces will become the new north or south poles of the smaller pieces. Hence, the two cut pieces will have their own north and south poles. 

The angular wave number k is used to express the number of radians in a unit of distance.

Angular wave number is inversely proportional to the wavelength; hence the formula: k = 2π/λ.

M → \(\frac{Hi}{Ho}\) = \(\frac{Di}{Do}\)

Where:
M = magnification
H = height of the image
Ho = height of the object
Do = distance from the object to the lens
Di = distance from the lens to the in-focus projected image

But Di = \(\frac{Hi * Do}{Ho}\) → \(\frac{20 * 30}{40}\)
Image distance(Di) = 15cm

No relative motion because when both the coil and the magnet are stationary there is no change in the magnetic flux hence, no current is induced in the coil.

Regular tires have treads which provide your tires with the ability to grip the road thereby enhancing traction. The tread also helps the vehicle to accelerate or decelerate, as well as to brake reliably.

S = ut + \(\frac{1}{2}\)at\(^2\)
40 = 0 x 10 + \(\frac{1}{2}\)a x 10\(^2\)
50a = 40
a = \(\frac{40}{50}\)
a = 0.8m/s\(^2\)

 volumetric expansion (γ) = 3 x linear expansion

Local action defect caused by the impurities present in zinc rod.

Lost voltage = I x R
= 4 x 0.55
= 2.2V