Question

Resistance of 30 ohm and 70 ohm are arranged in series across 220 volt supply. Find the time taken by this combination produce a heat of 14520 Joule

Answer 1

hey mate!

here is your answer:

total resistance =30+70=100ohm

voltage =220v

Heat=VIT

so, T=heat/VI

I=V/R

I=220/100=2.2 ampere

T=14520/220×2.2=14520/484=30 sec

Hope it helped ^_^

Answer 2

$heya \\ \\ \\ h = i {}^{2} \times r \times t \\ \\ \\ r = 30 + 70 = 100ohm \\ \\ i = 220 \div 100 \\ \\ i = 11 \div 5amp \\ \\ and \: h \: = 14520joule \\ \\ t = h \div (i {}^{2} \times r) \\ \\ t = 14520 \div (121 \div 25 \: \: \: \times 100) \\ \\ t = 30sec$