Question

Q 1) An electric iron of resistance 20 ohm takes a current of 5 ampere calculate the heat produce 30 sec? 
2) If it is rate as a 2000 watt how much current will draw from a sorce of 220 volt battery ?

Answer 1

we know tha H=Isquare Rt hence the heat is 5×5×20×30=1500 joules
b. we know tha P=IV
hence I=P by V which is 2000/220=9.09 amperes

Answer 2

Given :-

R = 20 Ω

I = 5 A

t = 30 s

H = I^2Rt

= (5)^2×20×30

= 15000 J

= 1.5 × 10^4 J

P = VI

I = 2000/220

I = 9.09 A