1. A 240V, 100W light bulb is connected to the mains. Calculate the current passing through
it
2. An electrical appliance is rated at 2.5 kW and is connected to the mains. Determine the
current flowing through it when connected to a 240V supply.
3. Explain why electrical appliances in some countries operate at 110V, while others operate
at 220V.
4. A circuit has three resistors connected in series, each with a resistance of 10Ω. Calculate
the total resistance of the circuit.
5. Two resistors with resistances of 20Ω and 30Ω, respectively, are connected in parallel.
Determine the equivalent resistance of the combination.
6. Describe the safety features and functions of a circuit breaker in a household electrical
system.
7. An electrical heater is rated at 1.5 kW and is used continuously for 6 hours a day.
Calculate the monthly energy consumption in kilowatt-hours (kWh).
8. Explain why electrical power is transmitted over long distances at high voltages.
9. Describe the difference between alternating current (AC) and direct current (DC) in terms
of voltage and direction of flow.
10. A faulty electrical appliance has a live wire coming into contact with its metallic body.
Describe how the Earth Wire functions to protect users from electric shocks in such a
scenario.
11. Define Double Insulation and explain its importance in electrical appliances. What types
of appliances commonly feature double insulation, and how does it reduce the risk of
electric shock?
12. A series circuit consists of three identical light bulbs connected to a 24 V battery. If one
of the bulbs suddenly burns out, what will happen to the brightness of the other two bulbs?
Explain.
13. In a parallel circuit, three resistors of 6 Ω, 8 Ω, and 12 Ω are connected to a 12 V
battery. Calculate the total current flowing through the circuit and the current through each
resistor.
14. A parallel circuit consists of two identical capacitors connected to a 200 V power supply.
If one of the capacitors is removed from the circuit, what will happen to the total capacitance
and the charge stored in the remaining capacitor? Explain.
15. A copper wire has a resistance of 2.0 Ω at 20°C. If the wire's temperature is raised to
100°C, calculate its new resistance. (Coefficient of resistivity of copper = 0.0039 Ω/°C)
16. An electric heater draws a current of 5.0 A when connected to a 240 V supply. Calculate
the power rating of the heater.
17. Two resistors, R1 and R2, are connected in series. If R1 is 6.0 Ω and R2 is 4.0 Ω,
determine the equivalent resistance of the combination.
18. In a parallel circuit, three resistors with resistances of 3.0 Ω, 4.0 Ω, and 6.0 Ω are
connected to a 12 V battery. Calculate the total current flowing through the circuit.
19. A circuit contains two resistors in parallel: R1 = 8.0 Ω and R2 = 12.0 Ω. The total current
in the circuit is 5.0 A. Calculate the potential difference across each resistor.
20. An electric iron is rated 1.5 kW when operated at 220 V. Calculate the resistance of the
iron's heating element.
21. Explain the difference between fixed resistors and variable resistors, giving examples of
their practical applications.
22. Discuss the working principle of a thermistor and its applications in temperature
measurement and control systems.
23. Explain the principle behind a Van de Graaff generator and its application in generating
high voltages.
24. Discuss the process of charging by friction and provide examples of everyday situations
where it occurs.
25. Explain the process of grounding and its role in electrical safety.
26. Describe the working principle of an electroscope and how it can be used to detect
electric charge.
27. Explain the challenges faced by the aviation industry due to static electricity during
aircraft refueling and suggest safety protocols to address them.
28. Describe real-world applications of static electricity and its beneficial use in industries
such as painting and printing.
29. Explain the concept of a diode and its fundamental purpose in an electronic circuit.
30. Analyze the operation of a light-emitting diode (LED) and its advantages over traditional
light sources.