5. A potential difference of 240 V is applied across a coil resistance. A current of 0.50 A flows through it. Calculate the energy dissipated as heat in ten minutes. a) 8.7 x 101 b) 7.2 x 10 J c) 5.6 x 10 J d) 34 x 101 6. A cylindrical copper rod has resistance R. It is reformed to twice its original length with no change of volume. Its new resistance is: a) R b) 8R (0) 4R d) 2R e) R/4. 7. A motor has a resistance of 85 ohm at 22C. When the motor runs at full load, its resistance increases to 100 ohms. The resistance temperature coefficient is 0.004. The rise in temperature of the motor will be nearly a) 20 b) 50C c) 70 C d) 100C 8. Three 3 ohm resistors are connected to form a triangle. What is the resistance between any two of the corners? a) 4/3 ohm b) 3/4 ohms c) 3 ohms d) 2 ohms 9. A certain capacitor, in series with a 720-2 resistor, is being charged. At the end of 10 ms its charge is half the final value. The capacitance is about: a) 20 F b) 14 pf c) 10 uF d) 7.2 F e) 9.6 F