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.
0.1μF
0.3μF
1.0μF
0.5μF
Correct answer is A
1/C = 1/0.3 + 1/0.5 + 1/0.2 = 10.3333
=> C = 1 / 10.3333 = 0.09677
≅ 0.1μF
∴ C = 0.1μF
Electrical appliances at home are normally earthed so that?
the appliances are maintained at a lower p.d than the earth
both the a.c and d.c sources can be used
a person touching the appliances is safe from electric shock
the appliances are maintained at a higher p.d than the earth
Correct answer is C
Earthing is used to protect you from an electric shock. It does this by providing a path (a protective conductor) for a fault current to flow to earth. It also causes the protective device (either a circuit-breaker or fuse) to switch off the electric current to the circuit that has the fault.
1.00 x 1020
2.56 x 10-18
2.56 x -17
1.00 x 1017
Correct answer is D
Current (I) = q/t → q = i x t
= 16 x 10-3 x 1
= 1.6 x 10-2C
But 1.6 x 10-19C = I electronic charge
1 coulomb = 1 / (1.6x10-19)
∴ 1.6 x 10-2 coulombs = 1 / (1.6x10-19) x 1.6x10-2 / 1
= 1.0 x 10-2 x 1019
= 1.0 x 1017
The instrument used for securing a large number of similar charges by induction is called
electrophorus
capacitor
proof-plane
electroscope
Correct answer is A
No explanation has been provided for this answer.
9.6J
2.4J
12.0J
7.2J
Correct answer is B
Energy stored = Ivt = current x back e.m.f x time
= 2 x 3 x 0.4
= 2.4J