Q. No.Figure (a) shows a conducting loop being pulled out of a magnetic field with a speed \(v\). Which of the four plots shown in Figure (b) may represent the power delivered by the pulling agent as a function of the speed \(v\)?
1. a
2. b
3. c
4. d
1. a
2. b
3. c
4. d
Two circular loops of equal radii are placed coaxially at some separation. The first is cut and a battery is inserted in between to drive a current in it. The current changes slightly because of the variation in resistance with temperature. During this period, the two loops:
| 1. | attract each other |
| 2. | repel each other |
| 3. | do not exert any force on each other |
| 4. | attract or repel each other depending on the sense of the current |
A small, conducting circular loop is placed inside a long solenoid carrying a current. The plane of the loop contains the axis of the solenoid. If the current in the solenoid is varied, the current induced in the loop is:
| 1. | clockwise |
| 2. | anticlockwise |
| 3. | zero |
| 4. | clockwise or anticlockwise depending on whether the resistance is increased or decreased |
A conducting square loop of side I and resistance R moves in its plane with a uniform velocity v perpendicular to one of its sides. A uniform and constant magnetic field B exists along the perpendicular to the plane of the loop as shown in the figure. The current induced in the loop is
1. Blv/R clockwise
2. Blv/R anticlockwise
3. 2Blv/R anticlockwise
4. zero
A bar magnet is moved along the axis of a copper ring placed far away from the magnet. Looking from the side of the magnet, an anticlockwise current is found to be induced in the ring. Which of the following may be true?
(a) The south pole faces the ring and the magnet moves towards it.
(b) The north pole faces the ring and the magnet moves towards it.
(c) The south pole faces the ring and the magnet moves away from it.
(d) The north pole faces the ring and the magnet moves away from it
Choose the correct option
1. (a), (b)
2. (b), (c)
3. (c), (d)
4. (a), (d)
A conducting rod is moved with a constant velocity \(v\) in a magnetic field. A potential difference appears across the two ends,
| a. | if \(\overrightarrow v \|\overrightarrow l\) | b. | if \(\overrightarrow v \|\overrightarrow B\) |
| c. | if \(\overrightarrow l \|\overrightarrow B\) | d. | none of these |
Choose the correct option:
| 1. | (a), (b) | 2. | (b), (c) |
| 3. | (d) only | 4. | (a), (d) |
A conducting loop is placed in a uniform magnetic field with its plane perpendicular to the field. An emf is induced in the loop if
| (a) | it is translated |
| (b) | it is rotated about its axis |
| (c) | it is rotated about a diameter |
| (d) | it is deformed |
Choose the correct option
1. (a), (b)
2. (b), (c)
3. (c), only
4. (a), (d)
A metal sheet is placed in front of a strong magnetic pole. A force is needed to
| (a) | hold the sheet there if the metal is magnetic. |
| (b) | hold the sheet there if the metal is nonmagnetic. |
| (c) | move the sheet away from the pole with uniform velocity if the metal is magnetic. |
| (d) | move the sheet away from the pole with uniform velocity if the metal is nonmagnetic. |
Neglect any effect of paramagnetism, diamagnetism and gravity.
Choose the correct option
| 1. | (a), (c), (d) |
| 2. | (b), (c), (a) |
| 3. | (c), (d), (a) |
| 4. | (a), (d), (c) |
A constant current \(i\) is maintained in a solenoid. Which of the following quantities will increase if an iron rod is inserted in the solenoid along its axis?
| a. | magnetic field at the centre |
| b. | magnetic flux linked with the solenoid |
| c. | self-inductance of the solenoid |
| d. | rate of Joule heating |
Choose the correct option:
1. (a), (b), (c)
2. (b), (c)
3. (c), (d)
4. (a), (b), (d)
Two solenoids have identical geometrical construction but one is made of thick wire and the other of thin wire. Which of the following quantities are different for the two solenoids?
(a) self-inductance
(b) rate of Joule heating if the same current goes through them
(c) magnetic field energy if the same current goes through them
(d) the time constant if one solenoid is connected to one battery and the other is connected to another battery
Choose the correct option
1. (a), (b)
2. (b), (d)
3. (c), (d)
4. (a), (d)
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