A house is supplied with a 240V a.c mains. To operate a door bell rated at 8v, a transformer is used if the number of turns in the primary coil of the transformer is 900. calculate the number of turns in the secondary coil of the transformer
A
30
B
240
C
248
D
450
E
1248
Verified Correct Answer: A.
Physical Principles & Numerical Solution
\(\frac{E_p}{E_s} = \frac{n_p}{n_s}\)
ns = 30
Source: Myschool Past Questions Archive (Record #33438)