Question

Qn:4

QUESTION 3 105? and applied voltage of water from 15°C to 90°C 3.2 If the water equivalent of the kettle is 150g, find how long it will take to raise a second itre [10) The heater element of an electric kettle has a constant resistance of of 240V. Calculate time taken to raise the temperature of one litre assuming that only 80% of the power input to-the kettle is usefully employed. 3.1 (5) of water through the same temperature range immediately after the first time. (5) QUESTION 4 Calculate the time taken for a 25kW furnace having an overall efficiency of 80% to melt 20kg of particular metal with the initial temperature of 20°C. The specific heat capacity of this particular metal is 896J/chg.; the melting point of the same metal is 657°C and its specific latent heat of fusion 402000J/kg. [10] QUESTION 5 A direct current (DC) distribution circuit made with copper conductors is 2km long per distributor Each one of the conductors has a diameter of 10mm and is carrying capacity must however be increased to 200A ner cond suitable to carry 50A. The current

Answer 1

Question 3.

Given dota Coreulote test teken b ) vwate り Kettre -47092-S- Col endole con ant C。) o- V - 240 z 2:28 1os &- 8, 82 R. 361042-S-丁 Cal erla e torre taken by wale Y to lua t- t 313 18-9 규 レ.gee t= 3610425

2 t= 11 non Sq see.