Math, asked by abhinavsarda61, 9 months ago

Electric heaters designed to be used on a 220 V electric supply line are rated as 11W. If the maximum supply current is 5A, how many electric heaters can be connected in parallel with each other across 220V supply line? How much total energy is consumed by these in 20 minutes?​

Answers

Answered by nessintin12
25

Step-by-step explanation:

let there be n no of resisitors in parallel with equal resistance

1/R = 1/r + 1/r +......+n/r

=)1/R= n/r

=) R = r/n .....(1)

WE KNOW THAT POWER (P) = V²/r

( we take this equation because in parallel voltage is same)

=)r= V²/P=(220 × 220)/11= 4400 ohm

by ohms law ,

I= V/ R = 220 × n/4400 =) 5 = n/20

=) n = 100 resistors

each power = 11W

as voltage is same

E = V²t ( 1/r + 1/r +....+100 times)

= 220 × 220× (100/r)× 20/60

= 220 × 220 × 100/4400 × 1/3

= 366.67 kW h

Similar questions