Class 12 Physics Chapter 1 Mcqs With Solution – Electric Charges and Fields : Electric Charges and Fields is the first chapter in Class 12 Physics and lays the foundation for understanding the behavior of electric charges, electric fields, and their interactions. This chapter explores fundamental concepts such as Coulomb’s Law, electric field intensity, electric dipole, and Gauss’s Law. Mastering these concepts is essential for students as they form the basis of advanced topics in physics.

In this article, we’ll review the important concepts covered in Chapter 1, followed by a set of 20 multiple-choice questions (MCQs) with answers to help you practice and reinforce your understanding.

Key Concepts in Electric Charges and Fields

Electric Charge: A fundamental property of matter, electric charges can either be positive or negative. Like charges repel each other, while opposite charges attract each other.
Coulomb’s Law: Coulomb’s Law states that the force between two point charges is directly proportional to the product of the charges and inversely proportional to the square of the distance between them.
Electric Field: An electric field is a region where an electric charge experiences a force. The electric field due to a point charge is represented by field lines that radiate outward for positive charges and inward for negative charges.
Electric Dipole: An electric dipole consists of two equal and opposite charges separated by a distance. It is a basic structure in the study of electric fields, particularly for understanding field behavior in complex charge systems.
Gauss’s Law: Gauss’s Law relates the electric flux through a closed surface to the charge enclosed by that surface. This law is essential for calculating electric fields in symmetric charge distributions.
Electric Flux: The total number of electric field lines passing through a given area is defined as electric flux. It’s measured in units of newton-meters squared per coulomb (Nm²/C).

Multiple Choice Questions (MCQs)

Here are 20 MCQs based on Chapter 1: Electric Charges and Fields. Each question is presented in both English and Hindi to help students understand the concept and practice effectively.

1. The SI unit of electric charge is:

(a) Volt
(b) Coulomb
(c) Newton
(d) Joule

Answer: (b) Coulomb

1. विद्युत आवेश की SI इकाई क्या है?

(a) वोल्ट
(b) कूलम्ब
(c) न्यूटन
(d) जूल

उत्तर: (b) कूलम्ब

2. Which of the following is a property of electric charge?

(a) Charges repel each other
(b) Charge cannot be transferred
(c) Like charges attract each other
(d) None of these

Answer: (a) Charges repel each other

3. The value of the electric constant (ε0\varepsilon_0ε0) is approximately:

(a) 8.85×10−12 C2/Nm28.85 \times 10^{-12} \, \text{C}^2/\text{Nm}^28.85×10−12C2/Nm2
(b) 9×109 Nm2/C29 \times 10^9 \, \text{Nm}^2/\text{C}^29×109Nm2/C2
(c) 1.6×10−19 C1.6 \times 10^{-19} \, \text{C}1.6×10−19C
(d) 3×108 m/s3 \times 10^8 \, \text{m/s}3×108m/s

Answer: (a) 8.85×10−12 C2/Nm28.85 \times 10^{-12} \, \text{C}^2/\text{Nm}^28.85×10−12C2/Nm2

4. Coulomb’s law is valid for:

(a) Point charges
(b) Moving charges
(c) Non-uniform charges
(d) None of these

Answer: (a) Point charges

5. Which of the following materials can be used as a conductor?

(a) Rubber
(b) Copper
(c) Wood
(d) Plastic

Answer: (b) Copper

6. Electric field lines begin on:

(a) Positive charges
(b) Negative charges
(c) Both charges
(d) None of these

Answer: (a) Positive charges

7. The SI unit of electric field is:

(a) Newton
(b) Volt
(c) Newton/Coulomb
(d) Coulomb

Answer: (c) Newton/Coulomb

8. The electric field inside a conductor is:

(a) Zero
(b) Constant
(c) Variable
(d) Infinite

Answer: (a) Zero

9. Two charges are separated by distance rrr. If the distance is doubled, the force between them becomes:

(a) Four times
(b) One-fourth
(c) Half
(d) Double

Answer: (b) One-fourth

10. The force between two point charges is inversely proportional to the:

(a) Square of the distance between them
(b) Distance between them
(c) Sum of their charges
(d) Product of their charges

Answer: (a) Square of the distance between them

11. What is the nature of electric field lines?

(a) They intersect
(b) They never intersect
(c) They are closed curves
(d) None of the above

Answer: (b) They never intersect

12. Which law states that electric flux through a surface is proportional to the charge enclosed?

(a) Coulomb’s Law
(b) Gauss’s Law
(c) Faraday’s Law
(d) Newton’s Law

Answer: (b) Gauss’s Law

13. An electric dipole is formed by two charges:

(a) of the same magnitude and opposite sign
(b) of the same magnitude and same sign
(c) with any magnitude
(d) None of these

Answer: (a) of the same magnitude and opposite sign

14. Electric flux is measured in:

(a) Nm²/C
(b) N/C
(c) J/C
(d) None of these

Answer: (a) Nm²/C

15. The direction of the electric field is taken to be:

(a) Outward from positive to negative
(b) Inward from negative to positive
(c) From positive to negative
(d) None of the above

Answer: (c) From positive to negative

16. Electric field lines are drawn such that:

(a) They diverge from negative charges
(b) They converge on positive charges
(c) They never cross each other
(d) Both (b) and (c)

Answer: (d) Both (b) and (c)

17. The net flux of an electric field through a closed surface is:

(a) Always zero
(b) Depends on the shape of the surface
(c) Zero if no charge is enclosed
(d) None of these

Answer: (c) Zero if no charge is enclosed

18. A charged body attracts:

(a) Only positively charged objects
(b) Only negatively charged objects
(c) Neutral objects
(d) None of these

Answer: (c) Neutral objects

19. The total electric flux through any closed surface depends on:

(a) Electric field inside
(b) Charge enclosed
(c) Charge outside
(d) Both (a) and (c)

Answer: (b) Charge enclosed

20. If two charges are doubled and the distance between them is also doubled, the force between them:

(a) Remains unchanged
(b) Becomes twice
(c) Becomes half
(d) Becomes four times

Answer: (a) Remains unchanged

Conclusion

This chapter lays down the basics of electric charges, fields, and the laws governing them, including Gauss’s Law and Coulomb’s Law. By practicing these MCQs, students can reinforce their understanding of fundamental concepts in “Electric Charges and Fields.”

Class 12 Physics Chapter 1 Mcqs With Solution – Electric Charges and Fields

Table of Contents

Key Concepts in Electric Charges and Fields

Multiple Choice Questions (MCQs)

Conclusion

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