JAMB - Physics (2023)

1
The property of wave shown in the diagram above is?

Απάντηση
(A)
Diffraction
2
Which of the following statements regarding the application of electrical conduction via gases is/are correct?
Electrical conduction in gas is applied in:
(i) The identification of gases
(ii) Lighting/fluorescent tubes
(iii) Photocells
(iv) Cathode ray oscilloscope/T.V. tubes

Απάντηση
(B)
(i), (ii) and (iv) only
3
Find the tension in the two cords shown in the figure above. Neglect the mass of the cords, and assume that the angle is 38° and the mass m is 220 kg

[Take g = 9.8 ms-2]
Απάντηση
(C)
\(T_1\)= 3502 N, \(T_2\)= 2760 N
4
A missile is launched with a speed of 75 ms-1 at an angle of 22° above the surface of a warship. Find the horizontal range achieved by the missile. Ignore the effects of air resistance.

[Take g = 10 ms-2]
Απάντηση
(C)
391 m
5
On a particular hot day, the temperature is 40°C and the partial pressure of water vapor in the air is 38.8 mmHg. What is the relative humidity?

Απάντηση
(A)
70
6
Calculate the absolute pressure at the bottom of a lake at a depth of 32.8 m. Assume the density of the water is 1 x 10^3 kgm-3 and the air above is at a pressure of 101.3 kPa.

[Take g = 9.8 ms-2]
Απάντηση
(A)
422.7
7
The terminals of a battery of emf 24.0 V and internal resistance of 1.0 Ω is connected to an external resistor 5.0 Ω. Find the terminal p.d.
Απάντηση
(D)
20.0V
8
A lorry accelerates uniformly in a straight line with acceleration of \(4ms^-2\) and covers a distance of 250 m in a time interval of 10 s. How far will it travel in the next 10 s?
Απάντηση
(A)
650
9
The half life of a radioactive material is 12 days. Calculate the decay constant.
Απάντηση
(D)
0.05775 \(day^{-1}\)
10
The number of holes in an intrinsic semiconductor
Απάντηση
(C)
is equal to the number of free electrons
11
Name the type of equilibrium for each position of the ball
Απάντηση
(D)
A - unstable, B - stable, C - neutral
12
Rainbow formation is as a result of the combination of which of the following phenomena?
(i) Reflection
(ii) Dispersion
(iii) Total internal reflection
(iv) Refraction
Απάντηση
(C)
(ii), (iii) and (iv) only
13
The surface temperature of a swimming pool on a warm day is 25ºC and the temperature at the bottom is 15ºC. If the swimming pool has a surface area of 620 \(m^2\) and a depth of 1.5m. Find the rate at which energy is transferred by conduction from the surface to the bottom of the swimming pool.

[Thermal conductivity of water (k) = 0.6071 Wm-1K-1]
Απάντηση
(A)
2.5kw
14
Which process is responsible for production of energy in stars?
Απάντηση
(C)
Nuclear fusion
15
How much net work is required to accelerate a 1200 kg car from 10\(ms^{-1}\) to 15\(ms^{-1}\)
Απάντηση
(C)
7.5×\(10^4 j\)
16
A wire of radius 0.2 mm is extended by 0.5% of its length when supported by a load of 1.5 kg. Determine the Young's modulus for the material of the wire.

[Take g = 10 ms\(^{-2}\)]
Απάντηση
(A)
\(2.4×10^{10}(Nm^{-2})\)
17
A man swung an object of mass 2 kg in a circular path with a rope 1.2 m long. If the object was swung at 120 rev/min, find the tension in the rope.
Απάντηση
(D)
379
18
A 200 kg load is raised using a 110 m long lever as shown in the diagram above. The load is 10m from the pivot P. If the efficiency of the the lever is 80%, find the effort E required to lift the load.

[Take g = 10ms-2]
Απάντηση
(A)
250
19
An air bubble of radius 4.5 cm initially at a depth of 12 m below the water surface rises to the surface. If the atmospheric pressure is equal to 10.34 m of water, the radius of the bubble just before it reaches the water surface is
Απάντηση
(D)
5.82 cm
20
A parallel plate capacitor separated by an air gap is made of \(0.8m^2\) tin plates and 20 mm apart. It is connected to 120 V battery. What is the charge on each plate?

Take \(ε_o\) = \(8.85×10^-12 Fm^-1\)
Απάντηση
(B)
42.5nC
21
What is the amount of heat required to raise the temperature of a 0.02 kg of ice cube from \(-10^oC\) to \(10^oC\) ?

[specific latent heat of fusion of ice = 3.34 x \(10^5\) \(Jkg^-1\), Specific heat capacity of water = 4200 \(Jkg^-1\) \(k^-1\)

Specific heat capacity of ice = 2100 \(Jkg^-1\) \(k^-1\)
Απάντηση
(D)
7940 J
22
Which of the following thermometers measures temperature from the thermal radiation emitted by objects?
Απάντηση
(A)
Pyrometer thermometer
23
A 400 N box is being pushed across a level floor at a constant speed by a force P of 100 N at an angle of 30.0° to the horizontal, as shown in the the diagram below. What is the coefficient of kinetic friction between the box and the floor?

Απάντηση
(A)
0.19
24
Light of wavelength 589 nm in vacuum passes through a piece of fused quartz of index of refraction n = 1.458. What is the frequency of the light in fused quartz?

[Speed of light c = \(3.00×10^8 ms^{-1}\)]
Απάντηση
(B)
\(5.09×10^{14}\) Hz
25
A simple pendulum, has a period of 5.77 seconds. When the pendulum is shortened by 3 m, the period is 4.60 seconds. Calculate the new length of the pendulum
Απάντηση
(A)
5.23 m
26
Three forces with magnitudes 16 N, 12 N and 21 N are shown in the diagram below. Determine the magnitude of their resultant force and angle with the x-axis
Απάντηση
(B)
8.71N,61°
27
A travelling wave of amplitude 0.80 m has a frequency of 16 Hz and a wave speed of 20 \(ms-1\)

Calculate the wave number of the wave.
Απάντηση
(C)
5
28
The near point of a patient's eye is 50.0 cm. What power (in diopters) must a corrective lens have to enable the eye to see clearly an object 25.0 cm away?
Απάντηση
(A)
2 diopters
29
Which of the following is/are not true about the heat capacity of a substance?
(i) It is an intensive property
(ii) Its S.I unit is \(jK-1\)
(iii) It is an extensive property
(iv) Its S.I unit is \(jkg-1\)
Απάντηση
(C)
(i) and (iv) only
30
The pinhole camera works on
Απάντηση
(B)
the principle of the rectilinear propagation of light
31
A step-down transformer is used on a 2.2 kV line to deliver 110 V. How many turns are on the primary windings if the secondary has 25 turns?
Απάντηση
(D)
500
32
A block of mass 0.5 kg is suspended at the 40 cm mark of a light metre rule AB that is pivoted at point E, the 90 cm mark, and is kept at equilibrium by a string attached at point D, the 60 cm mark, as shown in the figure above. Find the tension T in the string.

[Take g = \(10 ms-2\) ]
Απάντηση
(A)
16.67N
33
A 35 kΩ is connected in series with a resistance of 40 kΩ. What resistance R must be connected in parallel with the combination so that the equivalent resistance is equal to 25 kΩ?
Απάντηση
(B)
37.5 kΩ
34
A piano wire 50 cm long has a total mass of 10 g and its stretched with a tension of 800 N. Find the frequency of the wire when it sounds its third overtone note.
Απάντηση
(A)
800 Hz
35
An object is placed 35 cm away from a convex mirror with a focal length of magnitude 15 cm. What is the location of the image?
Απάντηση
(B)
10.5 cm behind the mirror
36
A relative density bottle has a mass of 19 g when empty. When it is completely filled with water, its mass is 66 g. What will be its mass if completely filled with alcohol of relative density 0.8?
Απάντηση
(D)
56.6 g
37
How much work is done against the gravitational force on a 3.0 kg object when it is carried from the ground floor to the roof of a building, a vertical climb of 240 m?
Απάντηση
(A)
7.2 kJ
38
A beam of light travelling in water is incident on a glass which is immersed in the water. The incident beam makes an angle of \(40^o\) with the normal. Calculate the angle of refraction in the glass.

[Refractive index of water = 1.33, Refractive index of glass = 1.5]
Απάντηση
(D)
\(34.75^o\)
39
An open-tube mercury manometer is used to measure the pressure in a gas tank. When the atmospheric pressure is 101,325 \(P_a\), what is the absolute pressure in \(P_a\) in the tank if the height of the mercury in the open tube is 25 cm higher. density of mercury = \(13600kg/m^3, g = 9.8m/s^2\)
Απάντηση
(D)
134,645 Pa
40
The sensitivity of a thermometer is
Απάντηση
(D)
the smallest temperature change that can be detected or measured
41
The diagram above illustrates the penetrating power of some types of radiation. X, Y and Z are likely
Απάντηση
(C)
X = γ-ray; Y = α-particle; Z = β-particle
42
An explosion occurs at an altitude of 312 m above the ground. If the air temperature is -10.00°C, how long does it take the sound to reach the ground?

[velocity of sound at \(0^oC\) = 331 ms-1]
Απάντηση
(B)
0.96s
43
A charge of \(4.6 × 10^{-5}\)C is placed in an electric field of intensity \(3.2 × 10^4\) \(Vm^{-1}\). What is the force acting on the electron?
Απάντηση
(A)
1.5 N
44
The branch of physics that deals with the motion of objects and the forces acting on them is called:
Απάντηση
(C)
Mechanics
45
The working of the beam balance is based on the principle of
Απάντηση
(A)
moments
46
Which of the following is a type of incandescent light source?
Απάντηση
(C)
Tungsten filament lamp
47
From the diagram above, if the potential differences across the resistor, capacitor, and inductor are 30V, 120V, and 60V, respectively, the effective potential difference is
Απάντηση
(B)
67
48
When light of a certain frequency is incident on a metal surface, no photoelectrons are emitted. If the frequency of the light is increased, what happens to the stopping potential?
Απάντηση
(D)
The stopping potential increases.
49
Which of the following is NOT a limitation of experimental measurements?
Απάντηση
(B)
Instrument resolution
50
Which of the following liquids has the highest surface tension?
Απάντηση
(C)
Mercury
51
What is the name of the model of the atom that describes electrons as orbiting the nucleus in specific energy levels?
Απάντηση
(A)
Bohr model
52
The electrolyte used in the Nickel-Iron (NiFe) accumulator is
Απάντηση
(C)
potassium hydroxide solution
53
Which of the following materials is a good insulator?
Απάντηση
(C)
Rubber
54
A generator manufacturing company accidentally made an AC generator instead of a DC generator. To fix this error,
Απάντηση
(D)
the slip rings should be replaced with split rings
55
Which of the following is NOT an example of elementary modern physics?
Απάντηση
(A)
Classical mechanics
56
Which of the following is an example of a couple?
Απάντηση
(A)
All of the above.
57
A positively charged particle is placed near a negatively charged particle. What is the direction of the electric force between the two particles?
Απάντηση
(D)
The electric force is directed from the positive particle to the negative particle.
58
When a water droplet is placed on a freshly cut piece of wood, it spreads out to form a thin layer because the wood is
Απάντηση
(D)
adhesive to water
59
Which of the following statements is correct about the angle of dip at various points on Earth?
Απάντηση
(A)
The angle of dip is zero at the equator and 90 degrees at the magnetic poles.
60
In the diagram above, if the south poles of two magnets stroke a steel bar, the polarities at X and Y will respectively be
Απάντηση
(C)
north and north