1. Statement A: If the length of a magnet increases, the magnetic induction on its axial line increases & that on equatorial line decreases.
Statement B: If a long barmagnet is held vertically with its north pole on the table, neutral point will be obtained on north side of the magnet.
1) A false, B true 2) A and B false
3) A and B true 4) A true, B false
2. With a bar magnet in vibration magnetometer the time period of oscillation is ‘6 sec’. It is made into 4 pieces normal to length and 3 pieces parallel to length then the new time period with one piece again is
1) 2 sec 2) 1.5 sec 3) 1 sec 4) 0.5 sec
3. When current is passed through a solid rod then,
1) Electric field is present both outside and inside the conducting rod.
2) Along the axis of the conductor only electric field is present and magnetic field is absent.
3) Magnetic field is absent inside the conductor and is present only outside the conductor.
4) Both electric and magnetic fields are present both inside and outside the conduction.
4.A metal wire of mass 0.1 kg slides without friction on two horizontal parallel rails separated by 0.5 m. The track is in a vertical uniform magnetic field of induction 2T. A current 0.2 A flows along one rail, across the wire and backdown the other rail. If the wire is initially at rest, velocity of the wire after 1 s is ………. m/s
1) 2 m/s 2) 4 m/s 3) 1 m/s 4) 5 m/s
5. a) Two parallel beams of electrons travelling in the same direction attract.
b) A thick rod carrying current can have a magnetic field inside and outside the rod.
c) An electron projected vertically up deflects towards the east in earths magnetic field
1) a & b true 2) b & c true 3) c & a true 4) a, b, c all true
6. If two rods of different materials with coefficients of linear thermal expansions in the ratio of 2:3. If the rods are fixed between two rigid walls and they do not bend on heating, the ratio of thermal stress developed will be equal to-
1) 2 :3 2) 2 :5 3) 3 :2 4) 5 : 2
7. A ball is dropped from a height of 30m. On hitting the ground, if it loses 40% of its energy it rebounds to a height equal to
1) 12m 2) 18m 3) 15m 4) 16m
8. A machine gun fires 360 bullets per minute. Each bullet moves with a velocity of 600 m/s. If the power of the gun is 5.4 KW. mass of each bullet is
1) 0.005 kg 2) 0.05 kg 3) 0.5kg 4) 5 kg
9. The momentum of a body is increased by 100%. The kinetic energy increases by
1) 300% 2) 200% 3) 100% 4) 50%
10. When two bodies of masses 1 kg and 25 kg are seperated by a certain distance, the resultant gravitational field in between them is zero at a distance 1m from 1kg. Then the distance between them would be
1) 6 m 2) 9 m 3) 16 m 4) 24 m
11. Two unlike poles of strength 25 A-m and 16 A-m are separated by a distance of 10 cm. The distance at which magnetic induction will be Zero is.
1) 40 cm from stronger pole 2) 40 cm from weaker pole
3) 50 cm from stronger pole 4) both (2) and (3) are correct
12. Two light springs have time periods of 3s and 4s with the same load. When the springs are connected in series and the same load is attached to them, the time period will be
1) 1s 2) 2.4s 3) 5s 4) 7s
Key: 1-4; 2-2; 3-2; 4-1; 5-2; 6-3; 7-2; 8-1; 9-1; 10-1; 11-4; 12- 3.