Answer to Question #267390 in Electricity and Magnetism for Kevin

Question

a. A transformer is used to change the 230 volt mains electricity supply to the 12 volts

needed to operate a low voltage halogen lamp. The current through the halogen lamp

is 4 amps. Assuming that the transformer is 100 % efficient determine the:

ii. number of turns on the primary coil if there are 200 turns on the secondary.

iii. power output of the transformer.

b. A metallic conductor of length 0.40m carrying a current of 5 A experiences a 

Force of 26N in a magnetic field of strength 15 T. Determine the angle between 

the current in the conductor and the magnetic field. 

Answer 1

a)

1)

$k=\frac{U_1}{U_2}=\frac{n_1}{n_2},\implies$

$n_1=n_2\frac{U_1}{U_2}=3833,$

2)

$P_2=U_2I_2=48~A,$

b)

$F=IBl\sin\alpha,\implies$

$\alpha=\arcsin \frac F{IBl}=60°.$