Question

Which uses more energy, a 250W TV set in 1 hour or a 1200W toaster in 10 minutes

Answer 1

work is also a form of energy.
so, w=p/t
hence, Tv set w1=250/3600 =0.0694 J
and toaster w2=1200/600= 2J
thus, toaster uses more energy as compared to the Tv set.

Answer 2

⇒ Power (P) TV = 250 W

⇒ Time Taken (t) = 1 hr

⇒ Heat = Power × Time

⇒ H = Pt

⇒ 250 W × 1hr

⇒ 250 Wh

therefore , the energy consumed by 250 W TV set in 1 hr = 250 Wh.

⇒ Power (P) Toaster = 1200 W

⇒ Time Taken (t) = 10 minutes

⇒ H = Pt

⇒ 1200 × 10/60

⇒ 200 Wh.

Therefore, Energy consumed by TV set is more than by the toaster in the giving timing.