Alternating Current - Result Question 36

38. The primary and secondary coil of a transformer have 50 and 1500 turns respectively. If the magnetic flux $\phi$ linked with the primary coil is given by $\phi=\phi_0+4 t$, where $\phi$ is in webers, $t$ is time in seconds and $\phi_0$ is a constant, the output voltage across the secondary coil is

[2007]

(a) 120 volts

(b) 220 volts

(c) 30 volts

(d) 90 volts

Show Answer

Answer:

Correct Answer: 38. (a)

Solution:

  1. (a) Since $\frac{V_s}{V_p}=\frac{N_s}{N_p}$

Where

$N_s=$ No. of turns across primary coil $=50$

$N_p=$ No. of turns across secondary coil $=1500$

and $V_p=\frac{d \phi}{d t}=\frac{d}{d t}(\phi_0+4 t)=4$

$\Rightarrow V_s=\frac{1500}{50} \times 4=120 V$