2.8 Problems 39current of 2 A the terminal voltage drops to 22 V. Determine the internal
resistance of the battery.
7 The winding of a motor has a resistance of 98 12 at a temperature of 16 ~
After operating for several hours the resistance is measured to be 114 f~.
Determine the steady state operating temperature of the winding. Take
the temperature coefficient of resistance to be 0.004 per ~
8 A 2.2 kf~ resistor has a tolerance of 10 per cent. What are the colour bands
on the body of this resistor?
9 A resistor having colour bands orange, orange, brown and silver is
connected in parallel with one with bands of yellow, violet, red and gold.
Determine the limits of resistance values of the combination.10 Capacitors of 5 IxF, 10 txF and 20 I~F are connected in series-parallel in all
possible ways. Calculate the values of capacitance obtainable.
11 A wooden ring having a mean diameter of 16 cm and a cross-sectional area
of 2 cm 2 is uniformly wound with 500 turns. A second coil of 400 turns is
wound over the first such that the coefficient of coupling is unity. Calculate
the inductance of each coil and the mutual inductance between them.
12 Calculate the two possible values of effective inductance obtainable by
connecting the two coils of Problem 11 in series electrically.
13 Two coils having self-inductances of 100 IxH and 50 txH are placed such
that the mutual inductance between them is 65 IxH. Determine the
coefficient of coupling.
14 The energy stored in a coil having an inductance of 30 IxH is 1.215 mJ.
Determine the current in the coil.
15 A capacitor having a capacitance of 0.1 txF has 200 V maintained across its
plates. Determine the energy stored in it.
16 A current of 6 A is passed through a resistor having a resistance of 40 fl.
Determine the power dissipated in the resistor.