Physics Questions and Answers
If you want to learn more about the nature and properties of matter and energy or you're simply preparing for a Physics exam, these Physics past questions and answers are ideal for you.
If you want to learn more about the nature and properties of matter and energy or you're simply preparing for a Physics exam, these Physics past questions and answers are ideal for you.
20 %
40 %
50 %
60 %
Correct answer is C
Efficiency = M.A/V.R X 100/1 M.A = Load/Effort = 500/250
= 2
V.R. = radius of wheel/radius of axle = 0.4/0.1 = 4.
therefore Efficiency = 2/4 x 100/1 = 50 %
3 : 5
4 : 5
7 : 10
13 : 10
Correct answer is B
Wt. in air = 0.25 N
Wt.in water = 0.15 N
therefore lost in wt. in water = Upthrust in water
= 0.25 - 0.15
= 0.10 N.
Wt. in paraffin oil = 0.17 N.
.. loss in wt.in oil = upthrust in the oil
Ratio upthrust in oil to upthrust in water
= 0.18/0.10 = 8/10 = 4/5 Or 4 : 5
The magnetic force on a charged particle moving with velocity v is
proportional to both the magnitude of the charge and the velocity v
independent of the magnitude of the charge
proportional to the velocity v only
proportional to the magnitude of the charge only
Correct answer is A
The magnetic force on a charge is given by
F = qVB Sinθ,
thus the force is proportional to both the magnitude by the charge (q) and the velocity (V)
(i/e F α qV)
I/16 H
I/8 H
I/64 H
I/32 H
Correct answer is D
Resonant, frequency in an a.c. circuit is given by F = I/2π√LC
therefore 200 * 103 = I/2 * π√l * 20 * 10-12
therefore (2.0 * 105)2 = I/4 * π2 * L * 20 * 10-12
THEREFORE L = I/4.0 * 1010 * 4 * 10 * 20 * 10-12
(if π2 = 10)
= I/16 * 1011 * 2.0 * 10-11
Therefore L = I/32 H
Energy losses through eddy currents are reduced by using
low resistance wires
insulated soft iron wires
few turns of wires
high resistance wires
Correct answer is B
No explanation has been provided for this answer.