Q20.A positive charge ' q ' of mass ' m ' is moving along the +x axis. We wish to apply a uniform magnetic field B for time Δt so that the charge reverses its direction crossing the y axis at a distance d. Then: (1) B = mvqd and Δt = πdv (2) B = 2qdmv and Δt = πd2v (3) B = 2mvqd and Δt = πd2v (4) B = 2mvqd and Δt = πdv
What This Question Tests
This question requires analyzing the circular motion of a charged particle in a uniform magnetic field to determine the magnetic field strength and the time needed to reverse its direction, involving radius and time period calculations.
Concepts Tested
Formulas Used
F = qvB
mv²/r = qvB
r = mv / (qB)
T = 2πm / (qB)
📚 NCERT Sections This Tests
4.11 — In A Chamber, A Uniform Magnetic Field Of 6.5 G (1 G = 10–4 T) Is
Physics Class 11 · Chapter 4
4.11 In a chamber, a uniform magnetic field of 6.5 G (1 G = 10–4 T) is maintained. An electron is shot into the field with a speed of 4.8 × 106 m s–1 normal to the field. Explain why the path of the electron is a circle. Determine the radius of the circular orbit. (e = 1.5 × 10–19 C, me = 9.1×10–31 kg)
4.4 — A Horizontal Overhead Power Line Carries A Current Of 90 A In East To
Physics Class 11 · Chapter 4
4.4 A horizontal overhead power line carries a current of 90 A in east to west direction. What is the magnitude and direction of the magnetic field due to the current 1.5 m below the line?
4.9 — A Square Coil Of Side 10 Cm Consists Of 20 Turns And Carries A Current
Physics Class 11 · Chapter 4
4.9 A square coil of side 10 cm consists of 20 turns and carries a current of 12 A. The coil is suspended vertically and the normal to the plane of the coil makes an angle of 30º with the direction of a uniform horizontal magnetic field of magnitude 0.80 T. What is the magnitude of torque experienced by the coil?
📋 Question Details
- Chapter
- Magnetic Effects of Current
- Topic
- Motion of charged particle in magnetic field
- Year
- 2014
- Shift
- 12 Apr Online
- Q Number
- Q20
- Type
- MCQ
- NCERT Ref
- Class 12 Physics Ch 4: Moving Charges and Magnetism
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