# 12th Board Exam Physics Chapter 4 Moving Charges & Magnetism Objective Question

Moving Charges And Magnetism

1. Accelerated charge produces :

(A) Alpha Rays

(B) Gamma Rays

(C) Beta Rays

(D) Electromagnetic Wave

2. A charged particle enters into a magnetic field at 30° with induction vector. Its path becomes

(A) circular

(B) helical

(C) elliptical

(D) straight line

3. When an ammeter is shunted, its measuring range

(A) increases

(B) decreases

(C) remains constant

(D) None of these

4. The resistance of an ammeter of range 1 ampere is 0.9 Ω. To increase its range to 10 amperes, the required shunt is

(A) 0.1 Ω

(B) 0.01 Ω

(C) 0.9 Ω

(D) 1 Ω

5. The magnetic effect of electric current was discovered by

(A) Ampere

(B) Oersted

(C) Fleming

6. A current of 10A exists in a straight wire. If it (wire) makes an angle of 30° with the magnetic field, the force on 1 meter of the wire will be

(A) 7.5 newton

(B) 15 newton

(C) 75 newton

(D) 150 newton

7. The magnetic field produced at the centre of a current bearing circular loop is directed

(A) in the plane of the coil

(B) normal to the plane of the coil

(C) at 45° with the plane of the coil

(D) at 18° with the plane of the coil

8. Uniform magnetic field is produced

(A) by a straight current bearing wire

(B) at the center by a circular loop bearing a current

(C) at an axial point due to current in a circular loop

(D) inside a solenoid due to its current direct

9. The rule to determine the direction of a Lorentz force is

(A) Fleming’s left-hand rule

(B) Fleming’s right-hand rule

(C) Maxwell’s right-handed screw-cork rule

(D) Ampere’s swimming person rule

10. The current in a wire is due east and the wire is placed in a north-directed magnetic field, the force on the wire will be directed

(A) eastward

(B) southward

(C) vertically downward

(D) vertically upward

11. To convert a galvanometer into an ammeter

(A) a low resistance is connected in parallel

(B) a high resistance is connected in series

(C) a low resistance is connected in series

(D) a high resistance is connected in parallel

12. A galvanometer can be converted into an ammeter by connecting with its

(A) a high resistance in parallel

(B) a high resistance in series

(C) a low resistance in series

(D) a low resistance in parallel

13. A voltmeter can be converted into an ammeter by connecting with it

(A) a high resistance in parallel

(B) a high resistance in series

(C) a low resistance in parallel

(D) a low resistance in series

14. The resistance of an ideal ammeter is

(A) small

(B) large

(C) infinite

(D) zero

15. The resistance of an ideal voltmeter is

(A) small

(B) large

(C) infinite

(D) zero

16. The SI unit of magnetic induction (B) is

(A) weber

(B) tesla

(C) gauess

(D) None of these

17. The electric current in a vertical wire is directed from bottom to top. If an electron beam is directed horizontally towards the wire, it gets deflected

(A) rightward

(B) upward

(C) downward

(D) leftward