1. Explain the characteristics of a parallel circuit.
2. Show that the alternating voltage and current are in-phase in resistive load.
3. A star connected 10000 V three phase alternator supplying 5000 kW at 0.8 pf. If the
total current remains same, when the load power factor is raised to 0.9. Find the new
output.
4. Find the total current in the given circuit. Also find the potential difference across 8
ohm and 6 ohm resistors, if the circuit is supplied with 21 V DC supply.
5. A house is supplied with 220 V AC, 50 Hz has the loads of 6 number of fans of 40 W
each, 6 lamps of 40 W each working for 5 hours daily, 5 lamps of 12 W each, one AC
having 320 W and a heater having 1200 W working for 2 hrs daily. Calculate the
monthly cost of energy if the tariff is Rs. 2.5 per unit.
Hint: Calculate kWh (units)
Monthly cost = kWh * 2.5
Calculation of kWh
For example: 6 lamps of 40 W each for 5 hours
Total wattage = 6* 40 = 240 W = 0.24 kW
Units consumed = 0.24 kW* 5 hours = 1.2 kWh = 1.3 units
Calculate the total units consumed for each load