2022 - JAMB Physics Past Questions and Answers - page 1
Which of the following is a derived unit?
Kilogram
Metre
Newton
Second
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).
If a bar magnet is divided into two pieces, which of the following statement is correct?
two new magnets are created
the magnetic field of each separate piece becomes stronger
the electric field is created
the bar magnet is demagnetized
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.
Consider the wave equation y = 5mm sin [1cm\(^{-1}\)x - 60s\(^{-1}\)t]. The wave number is?
0.1 cm\(^{-1}\)
10cm\(^{-1}\)
1.0cm\(^{-1}\)
2cm\(^{-1}\)
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.
An object 40 cm high is 30cm from the pinhole camera. If the height of the image formed is 20 cm. What is the distance of the image from the pin height?
15 cm
70 cm
40 cm
50 cm
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
A bar magnet is placed near and lying along the axis of a solenoid connected to a galvanometer. The pointer of the galvanometer shows no deflection when?
the magnet is moved towards the stationary solenoid
there is no relative motion
the magnet is moved away from the stationary solenoid
the solenoid is moved away from the stationary magnet
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.
Why do tyres have treads?
increase weight of tyres
increase friction
increase its longevity
look good
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.
A car starts from rest and covers a distance of 40 m in 10 s. Calculate the magnitude of its acceleration.
3.20 ms\(^{-2}\)
0.25 ms\(^{-2}\)
0.80 ms\(^{-2}\)
4.00 ms\(^{-2}\)
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\(^2\)
The relationship between the coefficient of linear expansion \(\alpha\) and volumetric expansion (\(\gamma\)) is-----------------
\(\gamma\) = \(\alpha ^{-3}\)
\(\gamma\) = \(\alpha\)
3\(\alpha\)
\(\gamma\) = \(\alpha ^{3}\)
Which of the following is not a consequence of hydrogen bubbles covering the copper plate of a primary cell?
formation of hydrogen bubbles on the electrode
increase in the resistance of the cell
local action
polarization
Local action defect caused by the impurities present in zinc rod.
A cell whose internal resistance is 0.55\(\Omega\) delivers a current of 4 A to an external resistor. What is the lost voltage of the cell?
4.00 V
2.20 V
0.15 V
8.00 V