The primary coil of a transformer has N turns and is connected to a 120 V a.c. power line. If the secondary coils has 1 000 turns and a terminal voltage of 1 200 volts, what is the value of N?
-
A.
120 -
B.
100 -
C.
1 000 -
D.
1 200
Correct Answer: Option B
Explanation
For the transformer, V ∝ ∩
=> V s ∝ ∩s; Vp ∝ ʌp
=> Vp/Vv = ∩p/∩s, therefore 120/1200 = ∩p/1000
therefore ∩p * 1200 = 120 * 1000
∩p = 120*1000/1200 = 100