State Ohm's law.
Ohm's law states that the current flowing through a conductor between two points is directly proportional to the voltage across the two points, provided physical conditions like temperature remain constant.
Define one-ampere electric current.
One ampere is defined as the flow of one coulomb of electric charge per second through a cross-section of a conductor.
What do you mean by electrical load?
An electrical load is a component or portion of a circuit that consumes electric power, such as appliances, lights, or machines.
What is the average value of an alternating current in one complete cycle?
In a complete cycle, the positive half and negative half cancel each other out.
Explain Kirchhoff's current law (KCL).
Kirchhoff's Current Law (KCL) states that the total current entering a junction or node is exactly equal to the total current leaving that node. This is based on the Law of Conservation of Charge.
For the given circuit, find the value of total resistance and value of branch currents I1, I2 and I3.
Circuit Data: Voltage (V) = 6V. Series resistor = 0.2 ohm. Parallel resistors: R1 = 2 ohm, R2 = 3 ohm, R3 = 6 ohm.
State differences between a.c. and d.c. If a sinusoidal signal has maximum value 200 mV, find r.m.s. value.
| Feature | A.C. Electricity | D.C. Electricity |
|---|---|---|
| Direction | Changes periodically | Remains constant |
| Source | Alternators, AC Mains | Batteries, Solar Cells |
Numerical: Given V_max = 200 mV.
What is the purpose of a ceiling rose?
A ceiling rose is used to provide a connection point for pendant light fittings or fans to the fixed wiring of a building.
Explain conduit wiring and concealed wiring. Mention one advantage.
Advantage: It provides high protection against mechanical damage and fire.
Define power factor.
Power factor is the ratio of the real power (kW) to the apparent power (kVA) in an electrical circuit.
What is the principle of transformer?
A transformer works on the principle of Faraday's Law of Mutual Induction. When an alternating current flows through the primary coil, it creates a changing magnetic flux, which induces an e.m.f. in the secondary coil.
Explain the working of a full-wave rectifier with necessary circuit diagram.
A full-wave rectifier converts both halves of the AC cycle into pulsating DC. It typically uses two diodes with a center-tapped transformer or four diodes in a bridge configuration.
What are the three types of electrical hazards?
The three main types are electrical shock, burns, and fires (including explosions).
What does the term overloading mean and how can it be prevented?
Overloading: This occurs when too many electrical appliances are connected to a single socket or circuit, drawing current beyond its rated capacity.
Prevention: