JAMB Physics Previous Year Questions: 2022 | Physics for JAMB PDF Download

Q1: Which of the following is a derived unit?
(a) Kilogram
(b) Metre
(c) Newton
(d) Second
Ans: (c)
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).

Q2: If a bar magnet is divided into two pieces, which of the following statement is correct?
(a) two new magnets are created
(b) the magnetic field of each separate piece becomes stronger
(c) the electric field is created
(d) the bar magnet is demagnetized
Ans: (a)
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.

Q3:Consider the wave equation y = 5mm sin [1cm⁻¹x - 60s⁻¹t]. The wave number is?
(a) 0.1 cm ^{− 1} 
(b) 10cm ^{− 1} 
(c) 1.0cm ^{− 1} 
(d) 2cm ^{− 1}
Ans: (c)
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 = 2?/?.

Q4: 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?
(a) 15 cm
(b) 70 cm
(c) 40 cm
(d) 50 cm
Ans: (a)

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

Image distance(Di) = 15cm

Q5: 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?
(a) the magnet is moved towards the stationary solenoid
(b) there is no relative motion
(c) the magnet is moved away from the stationary solenoid
(d) the solenoid is moved away from the stationary magnet
Ans: (b)
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.

Q6: Why do tyres have treads?
(a) increase weight of tyres
(b) increase friction
(c) increase its longevity
(d) look good
Ans: (b)
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.

Q7: A car starts from rest and covers a distance of 40 m in 10 s. Calculate the magnitude of its acceleration.
(a) 3.20 ms⁻² 
(b) 0.25 ms⁻² 
(c) 0.80 ms⁻² 
(d) 4.00 ms⁻²
Ans: (c)


Q8: The relationship between the coefficient of linear expansion α and volumetric expansion (γ) is______
(a) γ = α⁻³
(b)  γ = α
(c)  3 α
(d)  γ = α³ 
Ans: (c)
volumetric expansion (?) = 3 x linear expansion

Q9: Which of the following is not a consequence of hydrogen bubbles covering the copper plate of a primary cell?
(a) formation of hydrogen bubbles on the electrode
(b) increase in the resistance of the cell
(c) local action
(d) polarization
Ans: (c)
Local action defect caused by the impurities present in zinc rod.

Q10: A cell whose internal resistance is 0.55Ω delivers a current of 4 A to an external resistor. What is the lost voltage of the cell?
(a) 4.00 V
(b) 2.20 V
(c) 0.15 V
(d) 8.00 V
Ans: (b)
Lost voltage = I x R
= 4 x 0.55
= 2.2V

Q11: Which of the following liquid is a poor conductor of electricity?
(a) Distilled water
(b)Tap water
(c) Sea water
(d) Drinking water
Ans: (a)
Distilled water is free from electrolytes; it does not contain any salts, minerals or acids and hence doesn't have any conducting substance in it. In other words, it is a poor conductor of electricity.

Q12: An isotope has an initial activity of 120 Bq. 6 days later its activity is 15 Bq. What is half-life?
(a) 3 days
(b) 2 days
(c) 1 day
(d) 4 days
Ans: (b)
the amount left undecayed = A
the initial amount = A₀
the number of half-lives that passed in a period of time = t:

n = 3
6days/3 = 2 days

Q13: In order to remove the error of parallax when taking measurements with a metre rule, the eye should be focused___
(a) slantingly towards the right on the markings
(b) slantingly towards the left on the markings
(c) vertically downwards on the markings
(d) vertically upwards on the markings
Ans: (c)
Parallax is the apparent shift in the position of an object when viewed from different angles. When using a meter rule to take measurements, parallax can introduce errors if the eye is not focused correctly. To minimize parallax, the eye should be focused vertically downwards on the markings of the meter rule. This means that the eye should be directly above the point being measured, looking straight down onto the markings. By aligning the eye vertically with the markings, any potential parallax error is reduced, resulting in more accurate measurements.

Q14: An athlete standing waist-deep in a swimming pool appears to have short legs because of the light__?
(a) diffraction
(b) refraction
(c) reflection
(d) interference
Ans: (b)
Because the refractive index of water is greater than that of air the athlete's legs appear to be short while standing in the pool due to refraction.

Q15: A tuning fork that has a frequency of 312Hz emits a wave which has a wavelength of 1.10 m. Find the velocity of sound.
(a) 312.0 ms⁻¹ 
(b) 110.0 ms⁻¹ 
(c) 343.2 ms⁻¹ 
(d) 686.4 ms⁻¹
Ans: (c)
v = f ?
v = 312 x 1.10
= 343.2m/s

Q16: When the plate surface area of a capacitor increases, ___?
(a) the voltage can withstand increase
(b) the capacitance decreases
(c) the capacitance is unaffected
(d) the capacitance increases
Ans: (d)
As the surface area of the plates increases, capacitance increases because larger plates provide greater capacity to store electric charge.

Q17: An electromagnetic relay is a device used for?
(a) reading the magnitude of magnetic flux
(b) controlling another circuit carrying larger current
(c) turning in sports
(d) storing magnetic field
Ans: (b)
An electromagnetic relay is an electrically operated switch that uses a magnet to turn the switch on or off.

Q18: According to kinetic molecular model in gases,
(a) the particles are closely packed together; they occupy minimum space are usually arranged in a regular pattern
(b) the particles vibrate about fixed positions and are held together by the strong intermolecular bonds between them
(c) the molecules are very far apart and occupy all the spaces made available to them
(d) the particles occur in clusters with molecules slightly further apart
Ans: (c)
According to the kinetic molecular model in gases, gas particles are in constant motion and exhibit perfectly elastic collisions.
The main postulates of the theory are:
(1) the particles in a gas are in constant, random motion
(2) the combined volume of the particles is negligible
(3) the particles exert no forces on one another
(4) any collisions between the particles are completely elastic
(5) the average kinetic energy of the particles is proportional to the temperature in kelvins

Q19: A current of 0.5 A flows through a resistor when connected to a 40 V battery. How much energy is dispatched in 2 minutes?
(a) 2400 J
(b) 9600 J
(c) 1500 J
(d) 1200 J
Ans: (a)
Energy = power x time
Power = voltage x current.
Energy = voltage x current x time
Energy = 40 x 0.5 x 60 x 2
= 2,400j

Q20: For a pear-shaped conductor shown, the concentration of charge on the outside is highest at?
(a) X
(b) Z
(c) Y
(d) K
Ans: (a)
Electrons tend to concentrate on the location with more curvature, that is, sharp edges.

Q21: The vapour pressure___?
(a) increases non-linearly with measuring temperature
(b) increases linearly with increasing temperature
(c) decreases linearly with increasing temperature
(d) decreases non-linearly ith measuring temperature
Ans: (a)
According to Clausius–Clapeyron relation, the vapour pressure of any substance increases non-linearly with temperature.

Q22: The potential energy in an elastic string of force constant k, which has an extension X is?
(a) kX
(b) KX²
(c) ½KX² 
(d) ½K
Ans: (c)
Elastic potential energy[Ee]

Q23: A reservoir is filled with liquid of density 2000 kgm⁻¹. Calculate the depth at which the pressure in the liquid will be equal to 9100 Nm⁻² (g = 10 ms⁻²)
(a) 0.262 m
(b) 0.664 m
(c) 0.819 m
(d) 0.455 m
Ans: (d)
Let:
pressure = p
depth/height = h
density = d
gravity = g
p = hdg

h = 0.455m

Q24: Water is not a good thermometric liquid because it___?
(a) expands unevenly between 0 ºC and 4 ºC
(b) maintains fixed density
(c) has low freezing point
(d) wets glass
Ans: (d)
Because water wets glass, has a higher freezing point and lower boiling point than many other liquids, low thermal expansivity, high specific capacity, and high vapour pressure.

Q25: Which of these is a second-class lever?
(a) sugar tongs
(b) claw hammer
(c) plier
(d) wheelbarrow
Ans: (d)
Examples of second-class levers:

• bottle opener
• wheelbarrow
• an oar

Examples of first-class levers:

• weighing balance
• pliers
• claw hammer
• scissors
• crowbar

Q26: In the formation of sea breeze, the wind blows from?
(a) sky to land
(b) sea to sky
(c) land to sea
(d) sea to land
Ans: (d)
The formation of a sea breeze is a local wind pattern that occurs during the day near coastal areas. It is caused by the temperature difference between the land and the adjacent body of water, typically the sea. During the day, the land heats up more quickly than the water, leading to a temperature gradient between the two.

Q27: Which component of the fibre-optic connector has a provision of entry for the fibre along with the fixation to connector housing?
(a) couplers
(b) cable
(c) ferrule
(d) connector housing
Ans: (a)
Fibre optic couplers are used to split the input signals into two or more outputs, they are called splitters in this case. On the other hand, some types of couplers can be used to combine two or more inputs into one single output, they are called combiners in this case.

Q28: The most suitable instrument to view the sun is ___
(a) helioscope
(b) telescope
(c) stroboscope
(d) sun meter
Ans: (a)
A helioscope is an instrument for viewing the Sun without harming the eye. It is used for observing the sun and sunspots. The helioscope was first used by Benedetto Castelli and later refined by Galileo Galilei.

Q29: The eclipse of the moon occurs when?
(a) the moon reflects the rays from the sun to the earth
(b) the moon comes exactly between the earth and the sun
(c) the earth comes exactly between the moon and the sun
(d) the sun comes exactly between the earth and the moon
Ans: (c)
Lunar eclipses occur when Earth is positioned between the Moon and Sun and the Earth's shadow is cast on the surface of the Moon.

Q30: The gravitational pull on the moon is 1/6 that of the earth. If a body weighs 6.0 N on the moon, what will be its weight on the earth?
(a) 6.0 N
(b) 5.0 N
(c) 12.0 N
(d) 36.0 N
Ans: (d)
A body would weigh six times less on the moon than it weighs on Earth. In other words, the body would weigh six times more on the earth than it weighs on the moon.
Hence,
 = 6.0N on the moon
x = 6 * 6
x = 36

Q31: The amount of energy required to change a kilogram of ice block into the water without a change in temperature is?
(a) specific latent heat of fusion of ice
(b) specific heat capacity of ice
(c) heat capacity of ice
(d) specific heat of vaporization of ice
Ans: (a)
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.

Q32: Which expression gives the magnetic flux?
(a) qVB sinθ
(b)
(c) BA cos θ
(d)
Ans: (c)
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 ? or ?B, with the SI unit Weber
B = ?/A
Where:
B is magnetic flux density in teslas (T)
? is magnetic flux in webers (Wb)
A is area in square meters (m²).

Q33: The graph of pressure (P) against the reciprocal of the volume (I/V) in Boyles's law is a___?
(a) hyperbola
(b) parabola
(c) curve
(d) straight line
Ans: (d)
The graph of pressure (P) against the reciprocal of the volume (I/V) is a straight line passing through the origin.

Q34: What is the quantity of heat required to convert 20 g of ice at 0 ºC to water at the same temperature? (Specific latent heat of ice = 336 Jg⁻¹)
(a) 7.06 x 10³ J
(b) 5.38 x 10³ J
(c) 6.72 x 10³ J
(d) 1.35 x 10
Ans: (c)
Quantity of heat = mass * specific latent heat
⇒ 20 * 336
Quantity of heat = 6720j
= 6.72 x 10³J

Q35: A train of mass 1600kg attains a speed of 25ms⁻¹ in 20 seconds. The power developed in the engine is?
(a) 2.5 KW
(b) 80 KW
(c) 25 KW
(d) 50 KW
Ans: (d)
Let:
force = f
mass = m
acceleration = a
velocity = v
time = t


Q36: The main factor which affects the speed of sound wave is the?
(a) properties of the medium
(b) amplitude of the sound wave
(c) intensity of the sound wave
(d) loudness of the sound wave
Ans: (a)
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.

Q37: A semiconductor is formed by?
(a) co-ordinate bonds
(b) electrovalent bonds
(c) a substance free of bonds
(d) covalent bonds
Ans: (d)
Semiconductors are generally formed from silicon, germanium, or other pure elements, by adding impurities to the element.

Q38: Which of the following is a scalar quantity?
(a) weight
(b) momentum
(c) potential energy
(d) displacement
Ans: (c)
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

Q39: The mercury column in the barometer at natural atmospheric pressure has a height of?
(a) 0.76 cm at see level
(b) 760 cm at sea level
(c) 7.6 cm at sea level
(d) 76 cm at sea level
Ans: (d)
A standard mercury barometer measures atmospheric pressure by the height of a column of mercury that it supports. At sea level under normal atmospheric conditions, the average height of the mercury column is approximately 76 cm (or 760 mm). This value is also known as one standard atmosphere (atm) of pressure.

Q40: If an object just begins to slide on a surface inclined at 30º to the horizontal,the coefficient of friction is?
(a) ?3
(b) ?3/2
(c) 1/?2
(d) 1/?3
Ans: (d)
A body sliding down a plane inclined at 30º to the horizontal has coefficient of friction = tan 30º