Physics Past Questions and Answers

High Tension(H.T.) transmission means

A To transmit a given amount of power, the tension in the conducting wire must be high
B Heat is not lost when current is passed through a conductor
C Heat is gained when a given power is transmitted
D A big transformer is required to transmit power
E Trasmission of power at low current and high voltage

Question 32:

The best material for the core of the primary and secondary coils of an induction coil is

A Copper, because it has a good conductor of electricity
B Steel, because it becomes magnetic and retains its magnetism for a long time
C Rubber, because it is a good insulator and the user is prevented from shock
D Soft iron, because it becomes magnetic but easily loses its magnetism
E Glass, because it is transparent

Question 33:

Which of the following radiations cannot be deflected by a magnetic field?

A \(\alpha\)
B \(\beta\)
C \(\gamma\)
D \(\beta\) and \(\gamma\)
E None of them

Question 34:

Which of the following elements is the best absorber of X-rays?

A Hydrogen
B Oxygen
C Calcium
D Copper
E Lead

Question 35:

a calorimeter of thermal capacity 80j contains 20g of water at 25^oC. Water at 100^oC is added so that the final temperature of the set-ups is 50^oC. The amount of water added is (Heat capacity of water = 4.18J/g/^oC)

A 20g
B 25g
C 45g
D 50g
E 100g