The work done by friction is__________________?
(A) positive
(B) negative
(C) zero
(D) none of these
When arrow is released form its bow, its energy is transformed from _____________________?
(A) heat energy to K.E
(B) elastic P.E to K.E
(C) elemical energy to elastic P.E
(D) K.E to elastic P.
If moon radius is 1600 km and g on its surface is 1.6 ms-2 then the escape velocity on the moon is ___________________?
(A) 1600 ms-1
(B) 50.6 ms-1
(C) 71.6 ms-1
(D) 2263ms-1
The escape velocity form the earth surface in km S-1 is____________________?
(A) 4.2 km S-1
(B) 7.5 km S-1
(C) 9.5 km S-1
(D) 1.1 km S-1
The consumption of energy by a 60 watt bulb in 2 sec is_________________?
(A) 120 J
(B) 60 J
(C) 30 J
(D) 0.02 J
Which of the following is not conservative force_________________?
(A) friction
(B) electric
(C) gravitational
(D) magnetic
If velocity is doubled then__________________?
(A) momentum increases 4 times and K.E increases 2 times
(B) momentum and K.E. remain same
(C) momentum increases 2 times and K.E increases constant
(D) momentum increases 2 times and K.E increases 4 time
Work done by the force of friction is____________________?
(A) always positive
(B) always negative
(C) positive only for small frictional force
(D) positive only for large frictional force
The source of geothermal energy is___________________?
(A) decay of radioactive element in the earth
(B) compression of material in the earth
(C) residual lost of the earth
(D) all as said in A – B and C
The escape velocity of a body in gravitational field of earth is independent of__________________?
(A) its mass
(B) the angle at which it is thrown
(C) both its mass and the angle at which it is thrown
(D) gravitational field of earth