Magnetic fields

Question 1

Right hand rule for direction of magnetic field in a straight current carrying wire?

Answer 1

1. Grip wire with fingers of right hand
2. Thumb=direction of current
3. Direction in which fingers curl=direction of flow of magnetic field

Question 2

Formula for magnetic force on a length L of wire placed in a magnetic field?

Answer 2

F=BILsin θ
B=magnetic flux density
θ=angle between current and direction of magnetic field

Question 3

Magnetic force on a moving charge

Answer 3

F= qvBsinθ

Unit: Tesla(T)

Question 4

What is the magnetic force on an electrically neutral particle?

Answer 4

Zero

Question 5

Flemming’s right hand rule for direction of magnetic force on moving charge?

Answer 5

• Thumb, index and middle fingers at right angles to each other
• Thumb=Velocity of q
• Index finger=magnetic field
• Middle finger=force direction