Physics Past Questions and Answers

If negative charges are induced on an electroscope and a positively charged rod is brought near the cap of the electroscope, the leaves will

A Close up
B Become positively charged
C Become negatively charged
D Open further

Question 1447:

An electric lamp marked 240v, 60 W is left to operate for an hour. How much energy is generated by the filament?

A 3.86 x 105J
B 3.56 x 105J
C 1.80 x 104J
D 2.16 x 105J

Question 1448:

A band of 500 rectangular loops of wire of area 20 cm by 20 cm, encloses a region of magnetic field which charges from 1.0T to 0.4T within 5 seconds, calculate the induced e.m.f.

A 5.60 v
B 24.00 v
C 0.24 v
D 2.40 v

Question 1449:

Cancerous cells can be destroyed by

A Ultraviolet rays
B Alpha particules
C X - rays
D Infrared rays

Question 1450:

If the decay constant of a radioactive substance is 0.231s1, the half-life is?

A 3.00 s
B 0.12 s
C 0.33 s
D 1.50 s