Physics Past Questions and Answers

Which of the following electromagnetic waves is least energetic?

A Infra-red rays
B X-rays
C Ultra-violet rays
D Gamma rays

Question 1647:

Steel is more suitable for permanent magnet than iron because the former

A Is easily demagnetized by shaing vigorously
B Is an alloy of many metals
C Is easily magnetized by alternating current through one cycle
D Retains magnetism more than iron

Question 1648:

Four cells each of e.m.f 1.5V and internal resistance of 4Î© are connected in parallel. What is the effective e.m.f. and internal resistance of the combination?

A 6.0V, 16Î©
B 6.0V, 1Ω
C 1.5V, 4Î©
D 1.5V, 1Î©

Question 1649:

A 3000W electric cooker is to be used on a 200V mains circuit. Which of the fuses below can be used safely with the cooker?

A 2A
B 5A
C 10A
D 20A

Question 1650:

A galvanometer has a resistance of 5Î©. By using a shunt wire of resistance 0.05Î©, the galvanometer could be converted to an ammeter capable of reading 2Amp. What is the current through the galvanometer?

A 2mA
B 10mA
C 20mA
D 25mA