Physics questions and answers

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.

816.

What must be connected between the points P and Q to establish a steady current through the incomplete circuit diagram given?

A.

Fuse

B.

ammeter

C.

Cell

D.

voltmeter

Correct answer is C

No explanation has been provided for this answer.

817.

The angle which the direction of the earth magnetic field makes with the horizontal at a palace is know as.

A.

angle of contact

B.

angle of dip

C.

angle of declination

D.

magnetic meridian

Correct answer is B

No explanation has been provided for this answer.

818.

The mass of the earth is 6.0 x 1024kg and that of the moon is 7.0 x 1022kg. If the distance between them is 4.0 x 108m, calculate the force of attraction between them. [G = 6.7 x 10-11Nm2kg-2]

A.

1.8 x 105N

B.

1.8 x 1010N

C.

1.8 x 1015N

D.

1.8 x 1020N

Correct answer is D

F = \(\frac{GM_1M_2}{12^2}\)

F = 6.7 x 10-11x

F = \(\frac{M_1M_2}{R^2}\)

F = \(\frac{6.7 \times 10^{-11} \times 6.0 \times 10^{24} \times 7.0 \times 10^{22}}{(4 \times 10^8)^2}\)

= 1.8 x 1020N

820.

A wire of cross-sectional area 0.60mm2 has a restivity of 7.2 x 10-7 \(\Omega\). Calculate the length of wire that will have a resistance of 3\(\Omega\).

A.

0.25m

B.

2.50m

C.

3.60m

D.

36.00

Correct answer is B

R = \(\frac{PL}{A}\)

C = \(\frac{RA}{P}\)

C = \(\frac{0.60 \times 10^{-6} \times 3}{7.2 \times 10^{-7}}\)

C = 2.50m