Introduction
Current Electricity is an important chapter of Class 10 Physics that explains the movement of electric charges through conductors and the principles governing electric circuits. In this chapter, students learn about electric current, potential difference, resistance, resistivity, Ohm’s law, electrical power, electrical energy, and different combinations of resistors. These concepts form the foundation of electrical engineering and are widely applied in homes, industries, and electronic devices.
Students also study how current behaves in series and parallel circuits, how electrical energy is measured, and how safety devices such as fuses and circuit breakers protect electrical systems from damage. Understanding these concepts helps students solve numerical problems and explain the operation of many everyday electrical appliances.
This chapter is one of the most important topics in Class 10 Physics and frequently appears in school and board examinations. On this page, you will find carefully selected Class 10 Physics Chapter 5 MCQs with answers and explanations, along with learning outcomes, quick revision notes, important definitions, important formulas, exam tips, and common mistakes to help you prepare confidently for your examinations.
Learning Outcomes
After studying this chapter, students will be able to:
- Define electric current, voltage, resistance, and resistivity.
- Apply Ohm’s law to solve simple circuit problems.
- Differentiate between series and parallel circuits.
- Calculate electrical power and electrical energy.
- Explain the factors affecting the resistance of conductors.
- Understand the working of common electrical measuring instruments.
- Prepare effectively for Class 10 Physics examinations.
Quick Notes – Chapter Summary
- Electric current is the flow of electric charge through a conductor.
- The SI unit of current is the ampere (A).
- Potential difference provides the energy needed to move electric charges.
- Resistance opposes the flow of electric current.
- Ohm’s law states that voltage is directly proportional to current at constant temperature.
- Resistance depends on the length, cross-sectional area, and material of the conductor.
- Resistivity is a characteristic property of a material.
- In a series circuit, the current remains the same through all components.
- In a parallel circuit, the voltage remains the same across each branch.
- Electrical power is the rate at which electrical energy is converted into other forms of energy.
- Electrical energy consumed in homes is measured in kilowatt-hours (kWh).
- Fuses and circuit breakers protect electrical circuits from excessive current.
Important Definitions
Electric Current: The rate of flow of electric charge through a conductor.
Potential Difference: The work done per unit charge to move charge between two points.
Resistance: The opposition offered by a conductor to the flow of electric current.
Resistivity: The inherent property of a material that determines how strongly it resists electric current.
Ohm’s Law: The relationship stating that voltage is directly proportional to current at constant temperature.
Electrical Power: The rate at which electrical energy is converted into other forms of energy.
Electrical Energy: The energy supplied or consumed by an electric circuit.
Fuse: A safety device that protects electrical circuits by melting when excessive current flows.
Important Formulas
Ohm’s Law => V = IR
Electric Current => I = Q/t
Resistance => R = ρL/A
Electrical Power => P = VI
Electrical Energy => E = VIt
Where:
- V = Potential difference (Volt)
- I = Current (Ampere)
- R = Resistance (Ohm)
- Q = Electric charge (Coulomb)
- t = Time (Second)
- ρ = Resistivity
- L = Length of conductor
- A = Cross-sectional area
Class 10 Physics Chapter 5 – Current Electricity MCQs
1. The SI unit of electric current is:
- A. Ampere ✅
- B. Volt
- C. Ohm
- D. Coulomb
Explanation: Electric current is measured in amperes (A), defined as the flow of 1 coulomb of charge per second.
2. Which device is used to measure electric current?
- A. Ammeter ✅
- B. Voltmeter
- C. Ohmmeter
- D. Multimeter
Explanation: An ammeter is connected in series in a circuit to measure current.
3. Ohm’s law is represented by:
- A. V = IR ✅
- B. P = IV
- C. Q = It
- D. R = V/I²
Explanation: Ohm’s law states that voltage is directly proportional to current for a conductor at constant temperature.
4. The SI unit of resistance is:
- A. Ampere
- B. Volt
- C. Ohm ✅
- D. Watt
Explanation: Resistance is measured in ohms (Ω), defined as 1 volt per ampere.
5. Which factor decreases the resistance of a metallic conductor?
- A. Increase in length
- B. Increase in temperature
- C. Increase in cross-sectional area ✅
- D. Use of poor conductors
Explanation: A thicker conductor has more paths for electrons to flow, reducing resistance.
6. In series combination of resistors, the total resistance is:
- A. Sum of individual resistances ✅
- B. Product of individual resistances
- C. Reciprocal of individual resistances
- D. Equal to the smallest resistor
Explanation: For series circuits, R_total = R₁ + R₂ + R₃ …
7. In parallel combination of resistors, the reciprocal of total resistance is:
- A. Sum of reciprocals of individual resistances ✅
- B. Sum of individual resistances
- C. Difference of individual resistances
- D. Product of resistances
Explanation: For parallel circuits, 1/R_total = 1/R₁ + 1/R₂ + 1/R₃ …
8. Electric power is given by the formula:
- A. P = I/R
- B. P = VI ✅
- C. P = IR²
- D. P = V²/R²
Explanation: Power is the rate at which electrical energy is converted to another form, given by P = VI.
9. Which material is commonly used for making resistors?
- A. Copper
- B. Nichrome ✅
- C. Aluminium
- D. Silver
Explanation: Nichrome has high resistivity and low temperature coefficient, making it suitable for resistors.
10. The flow of electric charge per unit time is called:
- A. Electric current ✅
- B. Voltage
- C. Resistance
- D. Power
Explanation: Current measures the rate of flow of electric charge, usually in amperes.
11. Which instrument measures potential difference?
- A. Ammeter
- B. Voltmeter ✅
- C. Galvanometer
- D. Ohmmeter
Explanation: A voltmeter is connected in parallel to measure voltage between two points.
12. Electric energy consumed is given by:
- A. E = IR
- B. E = V/I
- C. E = VIt ✅
- D. E = I²V
Explanation: Energy is the product of voltage, current, and time.
13. What is the unit of electrical energy used in households?
- A. Joule
- B. Kilowatt-hour ✅
- C. Watt
- D. Megawatt
Explanation: 1 kWh = energy consumed by 1 kW appliance running for 1 hour.
14. Which combination of resistors provides the smallest possible resistance?
- A. Series
- B. Parallel ✅
- C. Mixed
- D. Variable
Explanation: Parallel connection allows multiple paths, reducing total resistance.
15. The resistivity of a conductor depends on:
- A. Nature of material ✅
- B. Length of conductor
- C. Cross-sectional area
- D. Voltage applied
Explanation: Resistivity is an intrinsic property determined by the material’s structure.
Exam Tips
– Memorize all SI units used in this chapter.
– Learn Ohm’s law and practice applying it to numerical problems.
– Understand the differences between series and parallel circuits.
– Revise all important formulas before the examination.
– Practice solving questions related to electrical power and energy.
Common Mistakes
❌ Confusing current with voltage.
❌ Mixing up resistance and resistivity.
❌ Forgetting the difference between series and parallel circuits.
❌ Using incorrect SI units in numerical problems.
❌ Forgetting that Ohm’s law is valid only when temperature remains constant.
Conclusion
Current Electricity forms the foundation of many electrical and electronic systems used in everyday life. Understanding electric current, resistance, Ohm’s law, electrical power, and circuit combinations helps students develop strong Physics concepts and problem-solving skills. Regular revision of the important formulas, definitions, and practice of these MCQs will improve conceptual understanding and help achieve excellent results in school and board examinations.