Polytechnic TRB Physics Model Question Paper with Answer Keys - 4

Question: 16

The function of heavy water in a nuclear reactor is to

(A) Cool down the reaction

(B) Stop the nuclear reaction

(C) Slow down the speed of neutrons

(D) Increase the speed of neutrons

Question: 17

The image form by an object of a compound microscope is

(A) real and enlarged

(B) real and diminish

(C) virtual and enlarged

(D) virtual and diminish

Question: 18

The boiling point of mercury is

(A) 100 K

(B) 200 K

(C) 357 K

(D) 400 K

Question: 19

When a body is taken from the earth to the moon

(A) its weight remains unchanged

(B) it becomes completely weightless

(C) its weight decreases

(D) its weight increases

Question: 20

When a bar magnet is cut into two equal halves, the pole strength of each piece

(A) remains the same

(B) becomes double

(C) becomes half

(D) becomes zero