2016 - JAMB Physics Past Questions and Answers - page 3
21
A metre rule is pivoted at its mid-point with a vertical force of 10N hanging from the distance 30cm from the mid-point. At what distance must a 15N force hang to balance the ruler horizontally?
A
30cm
B
10cm
C
20cm
D
25m
correct option: c
Clockwise moment = Anti-clockwise moment
10 x 30 = 15 x X
X = 20cm
Users' Answers & Comments10 x 30 = 15 x X
X = 20cm
22
A projectile is fired from the ground level with a velocity of 300ms-1 at an angle of a 30o to the horizontal.
Calculate the time taken to reach the maximum height?
[g = 10ms-2]
Calculate the time taken to reach the maximum height?
[g = 10ms-2]
A
30s
B
20s
C
25s
D
15s
correct option: d
t = \(\frac{u sin\theta}{g}\) = \(\frac{300 \text {sin} 30}{10}\) = 15s
Users' Answers & Comments23
A train with an initial velocity of 20ms-1 is subjected to a uniform deceleration of 2ms-2. The time required to bring the train to a complete halt is
A
40s
B
10s
C
20s
D
5s
24
Which of the following electromagnetic waves has the shortest wavelength?
A
Visible Light
B
Ultraviolet rays
C
Infrared rays
D
Gamma rays
correct option: d
Users' Answers & Comments25
A radioactive isotope has a decay constant of 10-6s-1.
Calculate its half - life?
Calculate its half - life?
A
5.93 x 106s
B
6.93 x 107s
C
6.93 x 109s
D
5.93 x 107s
correct option: b
t1/2 = \(\frac{0.693}{\gamma}\) = \(\frac{0.693}{10^-6}\)
= 6.93 x 107
Users' Answers & Comments= 6.93 x 107
26
Which of the following waves is both transverse and mechanical?
A
Water waves
B
Radio waves
C
Sound waves
D
X-rays
correct option: a
Users' Answers & Comments27
Calculate the temperature of 6 moles of an ideal gas at a pressure of 7.6 x 106Nm-2 with a volume of 10-3m3.
[R = 8.3jmol-1K-1]
[R = 8.3jmol-1K-1]
A
201oC
B
126oC
C
153oC
D
185oC
correct option: c
T = \(\frac{PV}{nR}\) = \(\frac{7.6 x 10^6 x 10^-3}{6 x 8.3}\)
= 153oC
Users' Answers & Comments= 153oC
28
The relative density of a liquid is the ratio of the
A
Mass of water to the mass of an equal volume of liquid
B
Upthrust in the liquid to the upthrust in water
C
Density of water to the density of the liquid
D
Upthrust in water to the upthrust in the liquid
correct option: b
Users' Answers & Comments29
What will happen to the pressure of a gas if its temperature is reduced to -273oC?
A
It will decrease
B
it will drop to zero
C
It will increase
D
It will remain constant
correct option: b
Users' Answers & Comments30
Which of the following does Not use magnetic effect of current to function?
A
Lead acid accumulator
B
An electric bell
C
A moving coil galvanometer
D
A telephone receiver
correct option: a
Users' Answers & Comments