(A) There will be no effect on the motion of electron
(B) The electron speed will increase but the direction will not change
(C) The electron speed will decrease but the direction will not change
(D) The electron speed will remain the same but it will move in a circle
Tag: Physics Mcq Questions and Answers
A long solenoid as 20 turns/cm. The current necessary to produce a magnetic field of 20 millitesla inside the solenoid is approximately:
(A) 1 A
(B) 2 A
(C) 4 A
(D) A
In a moving coil galvanometer the current i is related to the deflection 𝜽 as:
(A) i ∝ 𝜃
(B) i ∝ 𝑡𝑎𝑛 𝜃
(C) i ∝ 𝜃2
(D) i ∝ √𝜃
Two free parallel wires carrying currents in opposite directions:
(A) do not effect each other
(B) attract each other
(C) repel each other
(D) get rotated to be perpendicular to each other
The strength of e magnetic field due to a long straight conductor is:
(A) the same everywhere around the conductor
(B) inversely proportional to the distance from the conductor
(C) inversely proportional to the square of the distance from the conductor
(D) inversely proportional to the cube of the distance from the conductor
A moving charge produces:
(A) an electric field only
(B) a magnetic field only
(C) both electric and magnetic fields
(D) neither electric or a magnetic field
An electron is moving in a circle of radius r in a uniform magnetic field B. Suddenly he field is reduced to B/2. The radius of the circle now becomes:
(A) r/2
(B) r/4
(C) 2r
(D) 4r
Which of the following does not affect the motion of a moving electron?
(A) Electric field applied in the direction of motion
(B) Magnetic field applied I the direction of motion
(C) Electric field applied perpendicular to the direction of motion
(D) Magnetic field applied perpendicular to the direction of motion