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.
80.0W
40.0W
10.0W
0.1W
Correct answer is A
Power input = 3KW = 3000W
Voltage = 1.5KV = 1500V
Current (I) = P/V = 3000/1500 = 2Amps.
∴ Power loss in the cables = I2R
= 2 x 2 x 20
= 80W
∆x ∆Px ≥ h
∆x ∆Px = 0
∆x ∆Px < h
∆x ∆Px = ∞
Correct answer is A
No explanation has been provided for this answer.
A gas would serve as an electrical conductor under
reduced pressure and high current
increased magnetic field
reduced pressure and reduced potential
exposure to visible light
Correct answer is A
In general, gases conduct electricity under reduced pressure and high voltage/potential.
But from Ohms Law, current is directly proportional to voltage. Thus high current presupposes high voltage.
9.0 x 10-13J
9.0 x 10-12J
9.0 x 10-11J
9.0 x 10-10J
Correct answer is A
In thermonuclear reactions,
Energy = ∆mC2
∆m = Change in Mass
C = Speed of light
∴ 5.02 x 10-27 - 5.01 x 10-27 x [3 x 108]2
0.01 x 10-27 x 9 x 1016
E = 9.0 x 10-13J
in a pure semiconductor, the number of electrons in the conduction band is
less than the number of holes in the valence band
equal to the number of holes in the valence band
greater than the number of holes in the valence band
twice the number of holes in the valence band
Correct answer is B
No explanation has been provided for this answer.