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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

What is Condition for the path of a charged particle in uniform magnetic and uniform electric field to remain unchanged ?

E(electric)+ E(magnetic)= 0 ie
qE + q(V x B)=0 ie E=- (v x E)