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Electromagnetism
Class 12 · Physics · 8 questions
Name: ____________________ Date: ____________
The force on a charge q moving with velocity v perpendicular to a magnetic field B is:
- A q v B
- B q v / B
- C Zero
- D q B / v
A charged particle moving along the direction of a magnetic field experiences:
- A Maximum force
- B A force opposite to motion
- C A force along the field
- D No force
The magnetic field inside a solenoid depends on:
- A Only its length
- B Only its radius
- C Its colour
- D Turns per unit length and current
Ampere's law relates the line integral of B around a closed loop to the:
- A Flux
- B Current enclosed
- C Mass
- D Charge enclosed
A galvanometer is converted into an ammeter by connecting a:
- A Capacitor in parallel
- B Battery in series
- C Large resistance in series
- D Small resistance in parallel
The direction of force on a current carrying conductor in a field is given by:
- A Fleming's left hand rule
- B Lenz's law
- C Gauss's law
- D Fleming's right hand rule
The SI unit of magnetic flux density is the:
- A Weber
- B Tesla
- C Gauss only
- D Henry
The torque on a rectangular coil in a magnetic field is maximum when the plane of the coil is:
- A Parallel to the field
- B Never
- C At 45 degrees only
- D Perpendicular to the field
Answer key
1. A, 2. D, 3. D, 4. B, 5. D, 6. A, 7. B, 8. A
F = q v B sin 90 = q v B.
sin 0 = 0, so there is no force.
B = μ₀ n I.
The integral equals μ₀ times the enclosed current.
A low resistance shunt in parallel carries most of the current.
The left hand rule is for motors.
One tesla is one weber per square metre.
The force arms are longest then.