Physics Times 07.2019

(Kiana) #1


  1. A wire along x-axis carries a current 3.5A. The force
    on a 1 cm section of the wire exerted by the magnetic
    field






Magnetism & Matter
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Electro Magnetic Induction





12.

13.

14.

15.

B0.74T jˆ0.36T kˆ

(a) 2.59kˆ1.26 10ˆj ^2 N

(b) 1.26kˆ2.59 10ˆj ^2 N

(c) 1.26kˆ2.59 10ˆj ^2 N

(d) 2.59 1.26 10kˆ ˆj ^2 N

Magnetism & Matter


  1. A bar magnet of moment M is bent into arc, its
    moment now
    (a) Decreases (b) Increases
    (c) Does not change (d) May change

  2. A very long magnet is held vertically with its south
    pole on a table. A single neutral point is located on
    the table to the
    (a)East of the magnet (b) North of the magnet
    (c)West of the magnet (d) South of the magnet

  3. The coil in a MCG has an area of 4 cm^2 and 500


turns. The intensity of magnetic induction is 2 T.
When a current of 10 ^4 A is passed through it, the
deflection is 20 . The couple per unit twist is (N-
m/degree)
(a) 2 10 ^6 (b) 3 10 ^6 (c) 5 10 ^6 (d) 4 10 ^6


  1. Due to the earth’s magnetic field, charged cosmic
    ray particles
    (a) Can never reach the equator
    (b) Can never reach the poles
    (c) Require less kinetic energy to reach the equator
    than the poles
    (d) Require greater kinetic energy to reach the
    equator than the poles
    10.A magnet is placed on a paper in a horizontal plane
    for locating neutral points. A dip needle placed at
    the neutral point will be horizontal at the
    (a) Magnetic equator (b) Magnetic pole
    (c) Latitude angle of 60  (d) Latitude angle 45 


Electro Magnetic Induction

11.A coil of 40  resistance has 100 turns and radius


6 mm is connected to an ammeter of resistance of
160 . Coil is placed perpendicular to the magnetic

field. When coil is taken out of the field, 32 C
charge flows through it. The intensity of magnetic
field will be
(a) 5.66 T (b) 6.55 T
(c) 0.566 T (d) 0.655 T
12.An electromagnetic wave going through vacuum
is described byE E kx t 0 sin( );
B B kx t 0 sin( ). Which of the following is
true?
(a) E k B 0  0  (b) E B k 0  0
(c) E k B 0  2 0  (d) E B k0 0
13.An electric field of 300V/m is confined to a circular
area 10 cm in diameter. If the field is increasing at
the rate of 20V/m-s, the magnitude of magnetic field
at a point 15cm from the center of the circle will be-
(a) 1.85 10 T ^17 (b) 1.85 10 T ^15
(c) 1.85 10 T ^16 (d) 1.85 10 T ^18
14.A magnet is dropped down inside a long vertical
copper tube
(a) The magnet moves with continuously
increasing velocity and ultimately acquires a
constant terminal velocity
(b) The magnet moves with continuously
decreasing velocity and ultimately comes to
rest
(c) The magnet moves with continuously
increasing velocity but constant acceleration
(d) The magnet moves with continuously
increasing velocity and acceleration
15.Which of the following is constructed on the
principle of electromagnetic induction?
(a) Voltmeter (b) Galvanometer
(c) Generator (d) Electric motor

Magnetic Effects of Current


  1. a 2. d 3. d 4. d 5. a


Magnetism & Matter


  1. a 7. b 8. a 9. a 10. a


Electro Magnetic Induction


  1. c 12. a 13. d 14. a 15. c


Magnetic Effects of Current





















Magnetism & Matter





















Electro Magnetic Induction




















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