Physics Past Questions and Answers

²³₁₁Na + Proton â†’ ^p_qX + alpha particle
What are the values of p and q respectively in the equation above?

A 10 and 20
B 12 and 24
C 20 and 10
D 24 and 12

Question 37:

A semiconductor diode is used in rectifying alternating current into direct current mainly because it

A Allows current to flow in either direction
B Is non-linear
C Offers a high input resistance
D Allows current to flow only in one direction

Question 38:

if âˆ†x is the uncertainty in the measurement of the position of a particle along the x-axis and âˆ†P_x is the uncertainty in the measurement of the linear momentum along the x-axis, then the uncertainty principle relation is given as

A âˆ†x âˆ†P_x â‰¥ h
B ∆x ∆P_x = 0
C âˆ†x âˆ†P_x < h
D âˆ†x âˆ†P_x = âˆž

Question 39:

When a ship sails from salt water into fresh water, the fraction of its volume above the water surface will

A Increase
B Decrease
C Remain the same
D Increase then decrease

Question 40:

I. Its velocity is constant
II. No work is done on the body
III. It has constant acceleration directed away from the centre
IV. The centripetal force is directed towards the centre
Which combination of the above is true of a body moving with constant speed in a circular track?

A II and IV
B I and IV
C II and III
D I and III