A 60 W load is connected to the secondary of an ideal transformer whose primary draws line voltage. If a current of 0.54 A flows in the load, the current in the primary coil is

Question

A 60 W load is connected to the secondary of an ideal transformer whose primary draws line voltage. If a current of 0.54 A flows in the load, the current in the primary coil is (A) 0.27 mA (B) 2.7 A (C) 0.27 A (D) 10 A

Tardigrade Admin · Accepted Answer

Here, Ps = 60 W, Is = 0.54 A, Vp = 220 V ∴ Vs=(Ps/Is) (60/0.54) =111 V As (Vs/Vp)=(Ip/Is), for an ideal transformer ∴ Ip=(Vs/Vp)× Is =(111/220)×0.54 = 0.27 A

Q. A $60 W$ load is connected to the secondary of an ideal transformer whose primary draws line voltage. If a current of $0.54 A$ flows in the load, the current in the primary coil is

$0.27 m A$

$2.7 A$

$0.27 A$

$10 A$

Here, $P_{s} = 60 W$ ,
$I_{s} = 0.54 A$ ,
$V_{p} = 220 V$
$∴ V_{s} = \frac{P _{s}}{I _{s}}$
$\frac{60}{0.54}$
$= 111 V$
As $\frac{V _{s}}{V _{p}} = \frac{I _{p}}{I _{s}}$ , for an ideal transformer
$∴ I_{p} = \frac{V _{s}}{V _{p}} \times I_{s}$
$= \frac{111}{220} \times 0.54 = 0.27 A$

Q. A 60W load is connected to the secondary of an ideal transformer whose primary draws line voltage. If a current of 0.54A flows in the load, the current in the primary coil is

0.27mA

2.7A

0.27A

10A