Magnetism

Question 1

U0

Answer 1

4pi*10^-7 T m/A or 1.257x10^-6

Question 2

1 tesla is

Answer 2

1 N/A m

Question 3

|B| for a magnetic field induced by a wire =

Answer 3

u0*I/(2pir)

Question 4

Force caused by B for a moving charge

Answer 4

q|v||b|sintheta, charge affects sign

Question 5

How do u figure out the magnetic field direction for a current carrying wire

Answer 5

Use your right hand
Your thumb is direction of current, then you curl your fingers in direction of b field

Question 6

How do u figure out direction of force from particle velocity/magnetic field direction

Answer 6

Use your right hand and have it be flat. Thumb is velocity direction, the other fingers are b field direction and the force points up from your palm. It’ll point down from your palm if charge is negative

Question 7

Motion of q in uniform b field

Answer 7

R=mv/qB

Question 8

Currents in same direction do what? What about in opposite

Answer 8

Attract if same direction, else repel if opposite

Question 9

Torque on rotated loop

Answer 9

T=IABsintheta, theta is angle between normal and b field. A is area of loop

Question 10

Integral b *ds =?

Answer 10

0 if b field always perpendicular buti f it always parallel to the amperian loop it’s BL. This is also u0*I for currents

Question 11

Solenoid equation

Answer 11

Constant b field, B=u0I(N/L)

Question 12

If speed is constant, then what is work?

Answer 12

0 as W=delta KE

Question 13

Force on a current

Answer 13

F=ILBsintheta, flat right hand rule

Question 14

Equation for b field moving charge

Answer 14

B=(u0qvsintheta)/4pir^2. R is the distance between the point charge and the magnetic field point. Use cross product if seeing magnetic field right at point charge. V is velocity q is charge