NCERT Class 11 Physics Multiple Choice Questions(MCQs) & Answers
21 The electric potential V at any point O (x, y, z all in metres) in space is given by V = 4x² volt. The electric field at the point (1 m, 0, 2 m) in volt/metre is
Answer: 8 along negative x-axis
22 If a unit positive charge is taken from one point to another over an equipotential surface, then
Answer: no work is done.
23 A hollow metal sphere of radius 5 cm is charged so that the potential on its surface is 10 V. The potential at the centre of the sphere is
Answer: 10 V
24 The electrostatic force between the metal plates of an isolated parallel plate capacitor C having a charge Q and area A, is
Answer: independent of the distance between the plates.
25 A charged particle is moving in a cyclotron, what effect on the radius of path of this charged particle will occur when the frequency of the ratio frequency field is doubled?
Answer: It will remain unchanged.
26 Two a-particles have the ratio of their velocities as 3 : 2 on entering the field. If they move in different circular paths, then the ratio of the radii of their paths is
Answer: 3 : 2
27 A charged particle is moving on circular path with velocity v in a uniform magnetic field B, if the velocity of the charged particle is doubled and strength of magnetic field is halved, then radius becomes
Answer: 4 times
28 Which one of the following is correct statement about magnetic forces?
Answer: Magnetic forces do not obey Newton’s third law.
29 In an inertial frame of reference, the magnetic force on a moving charged particle is Its value in another inertial frame of reference will be
Answer: changed due to change in velocity of charged particle
30 Curie law xT = constant, relating magnetic susceptibility (x) and absolute temperature (T) of magnetic substance is obeyed by
Answer: paramagnetic substances.