Understanding the fundamentals of electricity is crucial in the realm of physics. Test your knowledge on this essential topic with these multiple-choice questions. Each question is followed by the correct answer and a brief explanation.
1. The electric charge of an electron is:
Answer:
Explanation:
An electron carries a negative charge.
2. A device that converts mechanical energy into electrical energy is:
Answer:
Explanation:
Generators convert mechanical energy into electrical energy.
3. Ohm’s Law states that:
Answer:
Explanation:
Ohm’s Law relates voltage (V), current (I), and resistance (R) in an electrical circuit.
4. The potential difference across a resistor when a current of 2 amperes flows through it with a resistance of 5 ohms is:
Answer:
Explanation:
Using Ohm’s Law, V = IR = 2A * 5Ω = 10V.
5. Which of the following is a good insulator?
Answer:
Explanation:
Rubber is an insulator and does not allow electricity to pass through it easily.
6. The unit of electric power is:
Answer:
Explanation:
Electric power is measured in watts.
7. In a series circuit:
Answer:
Explanation:
In a series circuit, the same current flows through each component.
8. Which device protects circuits from overloading by breaking the circuit?
Answer:
Explanation:
A fuse is designed to melt and break the circuit when the current exceeds a certain level.
9. The sum of all potential differences in a closed loop is:
Answer:
Explanation:
This is a statement of Kirchhoff’s voltage law.
10. A 60-watt bulb draws a current of 0.5 amperes. The potential difference across the bulb is:
Answer:
Explanation:
Using P = IV, V = P/I = 60W/0.5A = 120V.
11. Electrons flow from:
Answer:
Explanation:
Electrons flow from a region of low potential to a region of high potential.
12. The resistance of a wire depends on:
Answer:
Explanation:
Resistance is affected by the length, material, and cross-sectional area of the wire.
13. Which of the following cannot be used to control current in a circuit?
Answer:
Explanation:
Capacitors store energy and do not primarily control current.
14. A battery converts:
Answer:
Explanation:
Batteries convert stored chemical energy into electrical energy.
15. Which of the following is not a type of current?
Answer:
Explanation:
Static electricity refers to the build-up of electric charge on the surface of objects.
16. The instrument used to measure electric current is:
Answer:
Explanation:
An ammeter is used specifically for measuring electric current.
17. A device that allows current to flow in only one direction is:
Answer:
Explanation:
Diodes are semiconductor devices that allow current to flow in only one direction.
18. The unit of electric charge is:
Answer:
Explanation:
The unit of electric charge is Coulomb.
19. An electric cell has:
Answer:
Explanation:
An electric cell has two electrodes – a cathode and an anode.
20. The power of an appliance is 60W and it operates on 120V. The current drawn by the appliance is:
Answer:
Explanation:
Power = Voltage x Current => Current = Power/Voltage = 60W/120V = 0.5A.
21. Which of the following materials has the highest resistivity?
Answer:
Explanation:
Rubber, being an insulator, has a higher resistivity than metals like silver, copper, and aluminum.
22. Kirchhoff’s first law is based on the conservation of:
Answer:
Explanation:
Kirchhoff’s first law, or the junction rule, is based on the conservation of electric charge.
23. Which device is used to store electric charge?
Answer:
Explanation:
A capacitor is a device that stores electric charge.
24. The relationship between resistance (R) and temperature (T) for a metallic conductor is:
Answer:
Explanation:
For most metals, resistance increases with an increase in temperature.