Flashcards in Magnetism. Deck (23):

1

## What is Magnetic force on a moving charge ?

### F= q( V x B)= qVBsin #

2

## What are the 3 general paths of a charged particle in uniform charged field ?

###
If #=0 or 180, path is a straight line.

If #=90 , path is a circle.

For any other #, path is a helix. # is the angle between V and B

3

## In magnetism , What is radius r=?

### r= mv/qB=P/Bq= √2Km/Bq=√2qVm/Bq

4

## In magnetism, What is time period T and ω?

###
T= 2πm/qB

ω=qB/m

5

## In magnetism , What is radius r=?,time period T=? and frequency f=? for a particle in a helical path?

###
r= mv sin#/qB

T=2πm/qB

f=Bq/2πm

6

##
What is pitch of a helical path

p=?

### p= (v cos #)T=2πmv cos#/qB

7

## What is magnetic force due to a current carrying conductor ?

###
F= i(I x B)= ilBsin #

Here # is the angle between I and B or between direction of current an magnetic field.

8

## What is magnetic dipole moment M=?

###
M= NiA

Every current carrying loop in a magnetic dipole.

Direction of M is perpendicular to the plane of the loop and given by right hand screw law

9

## What is force on magnetic dipole due to a uniform magnetic field F=?

### F=0

10

## What is torque on magnetic dipole due to a uniform magnetic field ?

### Torque = M x B= MB sin #

11

##
What is potential energy U on magnetic dipole due to a uniform magnetic field

U=?

### U=-M.B= -MB cos #

12

## For magnetic dipole in an uniform magnetic field , what is the condition for unstable equilibrium position of the loop?

###
#=0 is the unstable equilibrium position of the loop.

F=0

Torque =0

U=MB( maximum )

13

## magnetic field due to a straight wire of finite length B=?

### B=μ₀/4π i÷r (sin α± sin β)

14

## What is magnetic field B due to a straight wire of uninvited length =?

### B=μ₀/2π i/r

15

## What is magnetic field B on the axis of a circular loop =?

### B= μ₀NiR²÷2(R² + x²)^3/2

16

## What is magnetic field B at the centre of circular loop = ?

### B= μ₀Ni/2R

17

## What is magnetic field B on the axis of a solenoid = ?

### B= μ₀ni/2 (cos #1- cos#2)

18

## What is magnetic field B at centre of a long solenoid = ?

### B = μ₀ni

19

## What is magnetic field B at the ends of a long solenoid = ?

### B= μ₀ni/2

20

## Mathematically , what is ampere's circuital law ?

### ∫B .dI = μ₀i( net)

21

## What is Force per unit length between two parallel current carrying wires ?

###
F/l= μ₀/2π x i₁i₂/r

There will be attraction if the currents are in the same direction and if currents re in opposite direction there will be repulsion.

22

## What is SI unit of magnetic field ?

### Tesla. = 1 Wb/ m^

23