JAMB 2021: PHYSICS REPEATED QUESTIONS AND ANSWERS JAMB

 

1 the velocity ratio of an inclined plane is
CORRECT ANSWER = 1/sinQ

2 where must an object be placed in front of the concave mirror so that the image will formed between the centre of curvature and the focus
CORRECT ANSWER = beyond the centre

3 optical instruments do NOT employ the principle of linear magnification in their operations rather they use
CORRECT ANSWER = angular magnification

4 the force of attraction between two masses m1 and m2 separated at a distance 2r is given as
CORRECT ANSWER = Gm1 m2/4r2

5 the condition for resonance to occur in an R-L-C serves circuit is
CORRECT ANSWER = W0 = 1/Lc

5 the condition for resonance to occur in an R-L-C serves circuit is
CORRECT ANSWER = W0 = 1/Lc

6 calculate the work done if a force of 10N applied at an angle of 30 0 to the horizontal moves the body through a distance of 0.05m
CORRECT ANSWER = 0.25 {3 J

7 the expression for electric potential (V) is
CORRECT ANSWER = (q / 4Er)

8 the expression for electric potential (V) is
CORRECT ANSWER = (q / 4Er)

9 a solid weighs 10.5N in air and weighs 5.5N when immersed in a liquid of density 900kgm-3, calculate the volume of the solid
CORRECT ANSWER = 5.56 x 10 -4 m 3

9 a solid weighs 10.5N in air and weighs 5.5N when immersed in a liquid of density 900kgm-3, calculate the volume of the solid

CORRECT ANSWER = 5.56 x 10 -4 m 3
10  during dispersion, colours of light
CORRECT ANSWER = travel at different speeds

11 cobvert 180 0F to 0C
CORRECT ANSWER = 82 0C

12 the bean balance is used to measure
CORRECT ANSWER = mass

13 the diagram above represents four identical beaker of water with some droplet of a blue colour pigment. Which of them will have a faster rate of diffusion?
CORRECT ANSWER = beaker IV

14 the diagram above represents four identical beaker of water with some droplet of a blue colour pigment. Which of them will have a faster rate of diffusion?
CORRECT ANSWER = beaker IV

15 a thick glass tumbler cracks when hot water is pour into it because of
CORRECT ANSWER = uneven expansion

16 the point M in the diagram above is in stable equilibrium with
CORRECT ANSWER = minimum potention energy

17 the charge stored by a 5F capacitor connected to a potential difference of 40V is
CORRECT ANSWER = 200C

18 the dissociation of salt solution and acids into ions is known as
CORRECT ANSWER = electroysis

19 the resultant of two parallel forces acting in the same direction applied to a block of wood will be
CORRECT ANSWER = maximum

20  from the above the induced e.m.f depends on
CORRECT ANSWER = I, II and III

21 how much current does a 120W light bulb draw when connected to a voltage of 240?
CORRECT ANSWER = 0.5A

22 from the above diagram the effective resistance between P and Q is
CORRECT ANSWER = 4.33n

23 a semi-conductor with equal numver of holes and electron is known as
CORRECT ANSWER = intrinsic semi-conductor

24 which of the following is CORRECT about the motion of a simple pendulum?
CORRECT ANSWER = potention energy is maximum at the extremes

25 in the vibration of stretched strings, the frequency F and the tension T are related by
CORRECT ANSWER = f & square root T)

26 from the diagram above, the pressure acting on the trapped air is
CORRECT ANSWER = H mmHg

27 light energy E is expressed as
CORRECT ANSWER = E = hf

28 the ejection of electron from the surface of a
CORRECT ANSWER = thermianic emission

29 where does refraction take place?
CORRECT ANSWER = at the boundary between

30 ten 6V cells connected in parallel will give an effective e.m.f of
CORRECT ANSWER = 6V

231vavpour is said to be saturated when
CORRECT ANSWER = in a dynamic equilibrium

31 a wire carries a current of 3.0A with a magnetic field 2.0T at an angle of 30 0. calculate the force on a segment of wire 0.5m
CORRECT ANSWER = 1.5N

32 which method of heat transfer is electro-mamgnetic in nature?
CORRECT ANSWER = radiation

33 a light of 6.22eV is incident on a cadmium surface. If a stopping voltage of 2.15eV is required to reduce the photocurrent to zero, calculate the work function of cadmium
CORRECT ANSWER =

34 from the digram above, calculate F
CORRECT ANSWER = 60.00N

35 which of the folowing exhibits a wave motion?
CORRECT ANSWER = a plucked stretched s tring

36 a stone weighs W1 Newton in air W2 Newton in water. The relative density of the stone is
CORRECT ANSWER = W1/(W1-W2)

37 why do pressure pots cook food faster than other conventional pots?
CORRECT ANSWER = its higher pressure

38 a spring of length 0.06m is acted upon by a force of 2N creating an extension of 0.02m. What would be the length when the applied force is increased by 8N?
CORRECT ANSWER = 0.14m

39 when a bar magnet is suspended freely in the earth’s magnetic field, it will point to
CORRECT ANSWER = north – south direction

40 the point where a ball moving in a viscous liquid start to move with uniform velocity is
CORRECT ANSWER = terminal velocity