A step down transformer connected to an ac mains supply of 220 V is made to operate at 11 V, 44 W lamp. Ignoring power losses in the transformer, what is the current in the primary circuit?

Question

A step down transformer connected to an ac mains supply of 220 V is made to operate at 11 V, 44 W lamp. Ignoring power losses in the transformer, what is the current in the primary circuit? (A) 0.2 A (B) 0.4 A (C) 2 A (D) 4 A

Tardigrade Admin · Accepted Answer

Vp=220 V Vs=11 V P=44 W As it is an ideal transformer VP iP=VS iS=44 W 220 × iP=44 iP=(44/220)=(1/5)=0.2 A

Q. A step down transformer connected to an ac mains supply of $220 V$ is made to operate at $11 V, 44 W$ lamp. Ignoring power losses in the transformer, what is the current in the primary circuit?

0.2 A

0.4 A

2 A

4 A

$V_{p} = 220 V$
$V_{s} = 11 V$
$P = 44 W$
As it is an ideal transformer
$V_{P} i_{P} = V_{S} i_{S} = 44 W$
$220 \times i_{P} = 44$
$i_{P} = \frac{44}{220} = \frac{1}{5} = 0.2 A$

Q. A step down transformer connected to an ac mains supply of 220V is made to operate at 11V,44W lamp. Ignoring power losses in the transformer, what is the current in the primary circuit?

0.2 A

0.4 A

2 A

4 A

Vp​=220V Vs​=11V P=44W As it is an ideal transformer VP​iP​=VS​iS​=44W 220×iP​=44 iP​=22044​=51​=0.2A

Q. A step down transformer connected to an ac mains supply of $220 V$ is made to operate at $11 V, 44 W$ lamp. Ignoring power losses in the transformer, what is the current in the primary circuit?

$V_{p} = 220 V$
$V_{s} = 11 V$
$P = 44 W$
As it is an ideal transformer
$V_{P} i_{P} = V_{S} i_{S} = 44 W$
$220 \times i_{P} = 44$
$i_{P} = \frac{44}{220} = \frac{1}{5} = 0.2 A$