Processing math: 100%
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.

2,876.

A certain radioisotope of 23592U emits four alpha particles and three beta particles. The mass number and the atomic number of the resulting elements respectively are

A.

219 and 87

B.

84 and 223

C.

223 and 87

D.

219 and 81

Correct answer is A

23592U 4(42α) + 3(01e) + bay

a + (4 + 2) + (3x - 1) = 92 a = 87

b + (4 x 4) + (3 x 0) = 235 b = 219

baY = 21987Y

2,877.

If two parallel conductors carry currents flowing in the same direction, the conducts will

A.

attract each other

B.

repel each other

C.

both move in the same direction

D.

have no effect on each other

Correct answer is A

No explanation has been provided for this answer.

2,879.

Two capacitors R1 = 4Ω and R2 = 5Ω are connected in parallel across a potential difference. If P1 and P2 represent power dissipated in R 1 and R2 respectively, then the ratio P1 : P2 is

A.

4 : 5

B.

5 : 4

C.

16 : 25

D.

25 : 16

Correct answer is B

P1 = V21R1 and P2 = V22R2

P1R1 = P2R2

4P1 = 5P2

p1p2 = 54

= 5 : 4

2,880.

A capacitor 8μF is charged to a potential difference of 100V. The energy stored by the capacitor is

A.

1.0 x 104J

B.

8.0 x 10J

C.

1.25 x 10J

D.

4.0 x 10-2J

Correct answer is D

Energy = 12CV2

= 12 x 8 x 10-6 x (100)2