1. A current is passed through a straight wire. The magnetic filed established around it has its of force ?

- Circular and endless
**correct** - All are true
- Parabolic
- Oval in shape and endless
- Straight

2. The permeability of free space is measured in ?

- Wb/Am
**correct** - None of these
- m/Web A
- Am/Wb
- Wb A/m

3. The magnetic filed inside a solenoid can be increased by ?

- Increasing I
- All correct except B
**correct** - By using iron core within the solenoid
- Decreasing I
- Increasing n

4. In the region surrounding a current carrying wire ?

- Direction of lines of force depends upon direction of current
- The lines of force are elliptical
- A magnetic field is set up
- Both A & C
**correct**

5. If the field is directed along the normal to the area, then flux is ?

- Both A & C
**correct** - Minimum
- Equal to BA
- Equal to Zero
- Maximum

6. The direction of magnetic lines of force around a current carrying wire is given by ?

- Right hand rule
**correct** - Faraday’s law
- Head to tail rule
- None of these
- Both A and B

7. The filed is uniform and much stronger ?

- Inside a long solenoid
**correct** - Outside a long solenoid
- None of these
- At the end of a long solenoid
- At the central point of a long solenoid

8. Magnetic lines of force ?

- Cannot intersect at all
**correct** - Intersect at neutral points
- Intersect at infinity
- Intersect within magnet

9. When some compass needles are placed on a card board along a circle with the centre at the wire, they will ?

- Point in the direction of N.S
**correct** - Set themselves tangential to the circle
- Point in the direction of E-W
- Point in the direction of S-E

10. Magnetic induction is also called ?

- Both A & B
- Both A & C
**correct** - Magnetic flux
- Magnetic flux density
- Magnetic field strength

11. Magnetic flux density at any point due to current carrying conductor can be computed by ?

- Lenz’s law
- Faraday’s law
- Coulomb’s law
- Ampere’s law
**correct** - Newton’s law

12. Magnetic filed is a ?

- Scalar quantity
- Scalar as well as vector quantity
- Vector quantity
**correct** - Neither A nor B

13. If a copper rod carries a direct current, the magnetic field associated with the current will be ?

- Only inside the rod
- Both inside and outside the rod
**correct** - Neither inside nor outside the rod
- Only outside the rod

14. The pointer of a magnetic compass ?

- Aligns itself perpendicular to the magnetic filed
- Vibrates in the magnetic filed of the current
- Is affected only by permanent magnets
- Aligns itself parallel to the applied magnetic filed
**correct**

15. If current carrying conductor is placed perpendicular to the magnetic fields, it will experience a force ?

- Zero
- Both A & B
- ILB
**correct** - ILB cos a

16. Amperean path is a ?

- Rectangular path
- Closed path
- Circular path
- Any of above
**correct** - Broken path

17. The unit of Iι I in case of solenoid is ?

- Any of A or B
- Both B and C
- Number of turns
- Ampere
**correct** - Metre

18. The strength of magnetic filed around a straight conductor ?

- Obeys inverse square law
- All are true
- Is same every where around the conductor
- None of these
**correct** - Is directly proportional to the square of distance from the conductor

19. Hold the solenoid in the right hand with finger curling in the direction of current. The direction of the filed will be given by ?

- Thumb
**correct** - Curled fingers
- Middle finger
- Arm of right hand

20. Tesla is unit of ?

- Magnetic flux
- Flux density
**correct** - Either A & B
- Electric flux

21. If the number of turns of a solenoid (carrying a steady current I) is doubled without changing the length of solenoid, then magnetic field ?

- Is not affected
- Becomes double
**correct** - Becomes one fourth
- None of these
- Becomes half

22. It is customary to represent a current flowing towards the reader by a symbol ?

- (+)
- (*)
- (-)
- (.)
**correct**

23. Total number of turns on 0.15 m length of solenoid is 300. The value of n is ?

- Equal to 300
- Greater than 300
**correct** - Smaller than 300
- Any of A or B
- Any of A or C

24. A current carrying conductor set up its own ?

- Magnetic filed
- Both A & C
**correct** - Electric filed
- Nuclear filed

25. A solenoid is a coil of wire which is ?

- Long, tightly wound, cylindrical
**correct** - Long, loosely wound, cylindrical
- None of these
- Long, tightly wound, spherical
- Short, loosely wound, cylindrical