Physics Past Questions and Answers

When a pure semiconductor is heated, its resistance

A Increases
B Decreases
C Remains the same
D Increases and then decreases

Question 37:

I. for current amplification.
II. for voltage stabilization.
III. for power amplification.
IV. as a switch.
which of the above are the uses of transistor?

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

Question 38:

The dimension of electromotive force are `

A ML²T^-3I^-1
B ML²T^-3I^-2
C M²LT^-2I^-1
D M²L²T^-1I^-1

Question 39:

The resultant of two forces 12N and 5N is 13N. What is the angle between the two forces?

A 0^o
B 45^o
C 90^o
D 180^o

Question 40:

A force F required to keep a 5 kg mass moving round a cycle of radius 3.5 m at a speed of 7 ms^-1. What is the speed, if the force is tripled?

A 4.0 ms^-1
B 6.6 ms^-1
C 12.1 ms^-1
D 21.0 ms^-1