A4-m × 5-m × 6-m room is to be heated by a base-board resistance heater. it is desired that the resistance heater be able to raise the air temperature in the room from 5 to 25°c within 17 min. assuming no heat losses from the room and an atmospheric pressure of 100 kpa, determine the required power of the resistance heater. assume constant specific heats at room temperature.

Question 7 [2 marks] in the circuit below, the electromotive force generated by the battery is e = 6.0 v, and the resistances are r1 = r4 = 1.0 q, r2 = r3 =2.0 q. r. the power delivered by the battery to the circuit is closest to a. 6 w в. 12 w с. 15 w d. 18 w e. 20 w final exam autumn 2014 page 5 of 9 68037 physical modelling faculty of science [2 mark] question 8 with reference to question 7, the current through resistor r2 is closest to a. 1 a в. 2 а c. 3 a d. 4 a e. 6 a