Physics Past Questions and Answers

Six dry cells each of e.m.f. 2.0 and internal resistance of 1.0\(\Omega\) are connected in parallel across a load of 3.0\(\Omega\). Calculate the effective current in the circuit.

A 0.63A
B 0.50A
C 0.31A
D 0.22A

Question 1497:

Two similar cells are used to light two similar lamps as illustrated in the diagrams above. In which of the circuit diagrams are the lamps brightest?

Question 1498:

A 120\(\Omega\) resistor dissipates 8 kJ of heat in 20s. Calculate the current through the resistor

A 5.8A
B 6.9A
C 30.0A
D 33.3A

Question 1499:

The magnetic relay is a device used for

A Timing in sports
B Storing magnetic field
C Readin the magnitude of magnetic flux
D Controlling another circuit carrying larger current

Question 1500:

the core of a transformer is usually laminated in order to

A Reduce magnetic leakage
B Reduce eddy current
C Prevent vibration of the transformer
D Make magnetic reversal in the core much easier