How long does it take a 750 W heater operating at full rating to raise the temperature of 1 kg of water from 40oC to 70oC? (Take the specific heat capacity of water as 4200 J kg-1 K-1 and neglect heat losses).
Take Free Practice Test On 2026 JAMB UTME, Post UTME, WAEC SSCE, GCE, NECO SSCE
Correct Answer: Option C
Explanation:
div class="eq-c">pt = mcθΔ; t =
mcθΔ/p
=
1 x 4200 x (70 - 40)/750
= 168s
div class="eq-c">pt = mcθΔ; t =
mcθΔ/p
=
1 x 4200 x (70 - 40)/750
= 168s