Physics(Electricity) by Vatika Harlalka - Friday, 10 September 2010, 2:12 PM Number of replies: 1 An electric kettle is rated 500W,200V.It is used to heat 400gm of water for 30 seconds.Assuming the voltage to be 220V, calculate the rise in temperature of water. Specific heat capacity of water is 4200J/Kg degree C. Permalink Reply In reply to Vatika Harlalka Re: Physics(Electricity) by Srinath Murthy - Sunday, 12 September 2010, 2:23 PM The resistance of the kettle remains the same at 200 V and at 220 V. Power is proportional to V2 in such case.Elec. Energy, (500 x 2202/2002) x 30 = Heat Transfer, 0.4 x 4200 x Delta TYou should be able to find Delta T from the above. Permalink Show parent Reply
In reply to Vatika Harlalka Re: Physics(Electricity) by Srinath Murthy - Sunday, 12 September 2010, 2:23 PM The resistance of the kettle remains the same at 200 V and at 220 V. Power is proportional to V2 in such case.Elec. Energy, (500 x 2202/2002) x 30 = Heat Transfer, 0.4 x 4200 x Delta TYou should be able to find Delta T from the above. Permalink Show parent Reply