Basic Electrical Q&A

1. What is the difference between AC and DC current?

AC (Alternating Current) changes direction periodically, while DC (Direct Current) flows in only one direction. AC is used in homes and industries because it can be transmitted over long distances. DC is commonly used in batteries and electronic devices because it provides a stable voltage.

2. What is electrical resistance, and how does it affect a circuit?

Electrical resistance opposes the flow of current and is measured in ohms (Ξ©). High resistance reduces current flow, while low resistance allows more current. It depends on material, length, thickness, and temperature. Resistors are used to control voltage and current in circuits.

3. What is the difference between series and parallel circuits?

In a series circuit, components are connected end to end, so the same current flows through all elements, but voltage is divided. In a parallel circuit, components share the same voltage source, and failure in one branch does not affect others.

4. What is a transformer, and how does it work?

A transformer changes the voltage of alternating current (AC) using electromagnetic induction. It consists of primary and secondary coils, where voltage is induced from one to the other. Step-up transformers increase voltage, while step-down transformers decrease it.

5. What is grounding, and why is it important?

Grounding connects an electrical system to the earth to prevent electric shocks and damage. It provides a safe path for excess electricity to flow into the ground in case of a fault, reducing the risk of fires and electrocution.

6. What is the difference between conductance and resistance?

Resistance (measured in ohms) opposes current flow, while conductance (measured in siemens) allows current to flow easily. A material with high resistance has low conductance and vice versa. Conductors like copper have low resistance, while insulators like rubber have high resistance.

7. What is the role of a fuse in an electrical circuit?

A fuse is a safety device that protects circuits from overcurrent. It contains a thin wire that melts when excessive current flows, breaking the circuit and preventing damage or fire. Blown fuses must be replaced, while circuit breakers can be reset.

8. What is Ohm’s Law, and why is it important?

Ohm’s Law states that V = I Γ— R, where V is voltage, I is current, and R is resistance. It helps in designing and troubleshooting electrical circuits by determining the relationship between voltage, current, and resistance.

9. What is the difference between electrical power and electrical energy?

Electrical power (watts) is the rate of energy usage, while electrical energy (joules or kWh) is the total power consumed over time. Power tells how fast energy is used, whereas energy measures the total consumption over a period.

10. What is an electrical symbol, and why is it used?

Electrical symbols represent components like resistors, switches, and transformers in diagrams. They make circuit designs easy to understand for engineers and electricians. Standard symbols ensure clear communication in electrical engineering and troubleshooting.