Eddy currents are used in:

1. Induction furnace

2. Electromagnetic brakes

3. Speedometers

4. All of these

Subtopic:  Eddy Current |
 94%
From NCERT
To view explanation, please take trial in the course.
NEET 2023 - Target Batch - Aryan Raj Singh
Hints
Links
To view explanation, please take trial in the course.
NEET 2023 - Target Batch - Aryan Raj Singh

A square loop of sides 4 cm having a resistance of 2Ω is placed normal to a magnetic field. If the magnetic field is gradually reduced at the rate of 0.02 T/s. The induced current in the loop is

1. 8 μA

2. 2 μA

3. 16 μA

4. 6 μA

Subtopic:  Faraday's Law & Lenz Law |
 86%
From NCERT
To view explanation, please take trial in the course.
NEET 2023 - Target Batch - Aryan Raj Singh
Hints
To view explanation, please take trial in the course.
NEET 2023 - Target Batch - Aryan Raj Singh

The direction of the runway on the airport should be

1. Along N-A

2. Along E-W

3. Along NW-SE

4. Along NE-SW

Subtopic:  Motional emf |
 58%
From NCERT
To view explanation, please take trial in the course.
NEET 2023 - Target Batch - Aryan Raj Singh
Hints
To view explanation, please take trial in the course.
NEET 2023 - Target Batch - Aryan Raj Singh

A metallic wheel (of radius l and 8 spokes) is rotated in a uniform magnetic field B as shown. The motional EMF across centre and rim is given by

1. 4Bl2ω

2. 2Bl2ω

3. 8Bl2ω

4. 12Bl2ω

Subtopic:  Motional emf |
 74%
From NCERT
To view explanation, please take trial in the course.
NEET 2023 - Target Batch - Aryan Raj Singh
Hints
To view explanation, please take trial in the course.
NEET 2023 - Target Batch - Aryan Raj Singh

Charged pollen grains are lying on a frictionless table. These are now subject to a certain field and are found to be moving by these fields. The field cannot be

1. Time-dependent electric field

2. Position dependent electric field

3. Time-dependent magnetic field

4. Position dependent magnetic field

Subtopic:  Faraday's Law & Lenz Law |
 51%
From NCERT
To view explanation, please take trial in the course.
NEET 2023 - Target Batch - Aryan Raj Singh
Hints
To view explanation, please take trial in the course.
NEET 2023 - Target Batch - Aryan Raj Singh

The magnetic field in the region is decreasing in such a way that dB/dt = γ. If resistance per unit length of the loop shown is λ, then, the current flowing in the loop is given by

1. 2πrγλ Clockwise

2. 2πrγλ Anticlockwise

3. rγ2λ Clockwise

4. rγ2λ Anticlockwise

Subtopic:  Faraday's Law & Lenz Law |
 53%
From NCERT
To view explanation, please take trial in the course.
NEET 2023 - Target Batch - Aryan Raj Singh
Hints
To view explanation, please take trial in the course.
NEET 2023 - Target Batch - Aryan Raj Singh

Two inductor coils of self-inductance L1 = 10 H and L2 = 20 H are placed as shown in the figure. The mutual inductance of the coil is 3H. The equivalent inductance between AB of the system of coils is

1. 36 H

2. 24 H

3. 203H

4. 383H

 

Subtopic:  Mutual Inductance |
 56%
To view explanation, please take trial in the course.
NEET 2023 - Target Batch - Aryan Raj Singh
Hints

There is a solenoid of length 1.5 m having 1000 turns per metre, kept in a region where the magnetic field is increased with time as 0.2 T s-1. (radius of the solenoid is 10πcm). The current through resistance 10Ω is

1. 30 A

2. 3 A

3. 0.3 A

4. 0.03 A

Subtopic:  Faraday's Law & Lenz Law |
 63%
From NCERT
To view explanation, please take trial in the course.
NEET 2023 - Target Batch - Aryan Raj Singh
Hints
To view explanation, please take trial in the course.
NEET 2023 - Target Batch - Aryan Raj Singh

A one-metre long metallic rod is rotated with an angular frequency of 400 radians/sec about an axis normal to the rod passing through its one end. The other end of the rod is in contact with a circular metallic ring. A constant uniform magnetic field of 0.5 tesla parallel to the axis exists everywhere. The emf developed between the centre and the ring is

1. 200 V

2. 100 V

3. 50 V

4. 1000 V

Subtopic:  Motional emf |
 77%
From NCERT
To view explanation, please take trial in the course.
NEET 2023 - Target Batch - Aryan Raj Singh
Hints
To view explanation, please take trial in the course.
NEET 2023 - Target Batch - Aryan Raj Singh

Self-inductances of primary and secondary of an ideal transformer are 90 mH and 40 mH. If the current in the primary decreases at the rate 103 As-1, then emf across the secondary is

1. 40 V

2. 90 V

3. 60 V

4. 20 V

Subtopic:  Mutual Inductance |
 60%
From NCERT
To view explanation, please take trial in the course.
NEET 2023 - Target Batch - Aryan Raj Singh
Hints
To view explanation, please take trial in the course.
NEET 2023 - Target Batch - Aryan Raj Singh