A hot electric iron has a resistance of 80 Ω and is used on a 200 V source. The electrical energy spent, if used for 2h, is

Question

A hot electric iron has a resistance of 80 Ω and is used on a 200 V source. The electrical energy spent, if used for 2h, is (A) 8000 Wh (B) 2000 Wh (C) 1000 Wh (D) 300 Wh

Tardigrade Admin · Accepted Answer

The resistance, R=80 Ω Voltage, V =200 V t =2 h The relation for power is given by D=P=(V2/R) =((200)2/80)=500 W The energy spent = power × time =500 × 2=1000 Wh

Q. A hot electric iron has a resistance of $80 Ω$ and is used on a $200 V$ source. The electrical energy spent, if used for $2 h$ , is

8000 Wh

2000 Wh

1000 Wh

300 Wh

The resistance, $R = 80 Ω$
Voltage, $V = 200 V$
$t = 2 h$
The relation for power is given by $D = P = \frac{V ^{2}}{R}$
$= \frac{( 200 ) ^{2}}{80} = 500 W$
The energy spent
$=$ power $\times$ time
$= 500 \times 2 = 1000 Wh$

Q. A hot electric iron has a resistance of 80Ω and is used on a 200V source. The electrical energy spent, if used for 2h, is