Question

an electric heater is rated 1000w how much energy does it use in 5 hours​

Answer 1

Answer:

p=v2/R

if V=220v we have

100w =220/R

R=220^/R

R=220^/100 pie =484pie. this is the resistance of the bulb .

when v=110V ,power consumed =v2/R=110^/484=25W

Explanation:

hope it's help

Answer 2

Power (p)= 1000 w = 1 kw

time (t) = 5 hrs = 5*3600 sec  =  18000 sec

Energy - work done (W) = ?

P = W / t

W = p*t = 1000 * 18000 = 18000000 = 18  Megajoule

Energy consmed = 18mj