Physics Chapter 8 Entry test MCQs
51. Which the following relations is correct?
a. I wb m-2 = 1 Tesla
b. 1 wb m-2 = N m-1A-1
c. 1 Tesla 104 Gausses
d. All of these
52. two long parallel wires wire 1 and wire 2 repel each other as shown in the figure. what could be the reasons?
a. Both carry current in the same direction
b. Both carry current in the opposite direction
c. wire 1 has current, but wire 2 has no current
d. wire 2 has current, but wire 1 has no current
53. The SI unit of magnetic flux is weber which is equal to:
a. Nam-1
b. NmA-1
c. AmA-2
d. Nm2A-1
54. Two long straight parallel wires held vertically, have equal but opposite currents as shown in figure.
which of the following effect will be observed
a. Magnetic field at ‘X’ is stronger than that at ‘y’ and ‘Z’
b. Magnetic field at ‘X’ and ‘Z’ are same
c. Magnetic field at ‘X’ is weaker than that at Z
d. Magnetic field at ‘X’ is weaker than that at out, stronger than that at ‘Z’
55. A long straight current carrying conductor has current direction from bottom to top when held vertically. What will be the direction of magnetic field lines when observed from below the conductor?
a. Anticlockwise
b. Clockwise
c. Vertically downward
d. Vertically upward
56. Due to current in straight conductor the distance between magnetic field lines.
a. Decreases away from conductor
b. Increases away from conductor
c. Decreases and then increases towards conductor
d. Increases towards conductor
57. If the value of magnetic flux is 10Wb, when magnetic lines of force containing magnetic field strength of ITesla passing through unit area of 10m2 then the angle between magnetic field and unit area is:
a. 90°
b. 180°
c. 45°
d. 360″
58. A charge is projected with velocity of 10m/s in a magnetic field of 10T at angle of 60°. If force of 2.78 x 10-17 N is exerted on the charge then value of charge will be:
a. 4.8 x 10-19C
b. 1.6 x 10-19C
c. 3.2 x 10 -19C
d. 2.7 x 10-19 C
59. electric current is flowing through a straight conductor as shown in figure given below. The direction of magnetic lines of force will be
a. Anticlockwise
b. clockwise
c. from bottom to top
d. from top to bottom
60. Two long, parallel conductors which are free to move are arranged 1.0 cm apart. A steady current of 20 A flows in each of the conductor in the same direction. The conductors
a. move away from each other
b. remain stationary
c. move at right angles to each other
d. move towards each other
61. A neutron having mass equal to a proton ( m = 1.6 x 10-27 kg) is moving in a magnetic field of intensity 1.2 x 10-3 T with a speed of 2 x 10-7 ms-1 . what is the Maximum force experienced by the neutron.
a. 3.84 x 10-12 N
b. 3.84 x 10-15N
c. 38.4 x 10-15N
d. 0 N
62. e/m of an electron is given by the relationship
a. e/m = Vr/B
b. e/m = 2(V/B2r2)
c. e/m = VB/r
d. e/m = (V/Br2)
63. Magnetic flux is maximum when angle between magnetic field and vector area is
a. 180°
b. 0°
c. 45°
d. 90°
64. Formula of toroid for magnetic field is
a. µoNI/2π
b. µoNI
c. µoI
d. µoNI/2πr
65. Unit of Magnetic flux
a. Tm²
b. Weber
c. Both A and B
d. Tesla
66. Magnitude of magnetic field of Earth
a. 6T
b. 0.6 G
c. 4T
d. 0.4 T
67. Magnetic force depends upon
a. Magnetic field
b. Current
c. Length
d. All