NCERT Solutions class 12 physics Electric Charges and Field Part 1

NCERT Solutions class 12 physics Electric Charges and Field Part 1 Class 12 Physics book solutions are available in PDF format for free download. These ncert book chapter wise questions and answers are very helpful for CBSE board exam. CBSE recommends NCERT books and most of the questions in CBSE exam are asked from NCERT text books. Class 12 Physics chapter wise NCERT solution for Physics part 1 and Physics part 2 for all the chapters can be downloaded from our website and myCBSEguide mobile app for free.

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NCERT Class 12 Physics Chapter-wise Solutions

• 1 – Electric Charges and Fields
• 2 – Electrostatic Potential and Capacitance
• 3 – Current Electricity
• 4 – Moving Charges and Magnetism
• 5 – Magnetism and Matter
• 6 – Electromagnetic Induction
• 7 – Alternating Current
• 8 – Electromagnetic Waves
• 9 – Ray Optics and Optical Instruments
• 10 – Wave Optics
• 11 – Dual Nature of Radiation and Matter
• 12 – Atoms
• 13 – Nuclei
• 14 – Semiconductor Electronic: Material, Devices and Simple Circuits
• 15 – Communication Systems

CHAPTER 1 ELECTRIC CHARGES AND FIELDS

• 1.1 Introduction
• 1.2 Electric Charges
• 1.3 Conductors and Insulators
• 1.4 Charging by Induction
• 1.5 Basic Properties of Electric Charge
• 1.6 Coulomb’s Law
• 1.7 Forces between Multiple Charges
• 1.8 Electric Field
• 1.9 Electric Field Lines
• 1.10 Electric Flux
• 1.11 Electric Dipole
• 1.12 Dipole in a Uniform External Field
• 1.13 Continuous Charge Distribution
• 1.14 Gauss’s Law
• 1.15 Application of Gauss’s Law

NCERT Solutions class 12 physics Electric Charges and Field Part 1

1: What is the force between two small charged spheres having charges of  and placed 30 cm apart in air?

2: The electrostatic force on a small sphere of charge due to another small sphere of charge – in air is  (a) What is the distance between the two spheres? (b) What is the force on the second sphere due to the first?

3: Check that the ratio  is dimensionless. Look up a Table of Physical Constants and determine the value of this ratio. What does the ratio signify?

4: (a) Explain the meaning of the statement ‘electric charge of a body is quantised’.

(b) Why can one ignore quantisation of electric charge when dealing with macroscopic i.e., large scale charges?

5: When a glass rod is rubbed with a silk cloth, charges appear on both. A similar phenomenon is observed with many other pairs of bodies. Explain how this observation is consistent with the law of conservation of charge.

6 : Four point charges  = C, = –C, = C, and = –C are located at the corners of a square ABCD of side 10 cms. What is the force on a charge of 1 C placed at the centre of the square?

7 : (a) An electrostatic field line is a continuous curve. That is, a field line cannot have sudden breaks. Why not?

(b) Explain why two field lines never cross each other at any point?

8 : Two point charges  C and  are located 20 cm apart in vacuum.

(a) What is the electric field at the midpoint O of the line AB joining the two charges?

(b) If a negative test charge of magnitude is placed at this point, what is the force experienced by the test charge?

9 : A system has two charges C and  C located at points A: and respectively. What are the total charge and electric dipole moment of the system?

10: An electric dipole with dipole moment is aligned at with the direction of a uniform electric field of magnitude Calculate the magnitude of the torque acting on the dipole.

11:   A polythene piece rubbed with wool is found to have a negative charge of

(a) Estimate the number of electrons transferred (from which to which?)

(b) Is there a transfer of mass from wool to polythene?

12: (a) Two insulated charged copper spheres A and B have their centers separated by a distance of 50 cm. What is the mutual force of electrostatic repulsion if the charge on each iss? The radii of A and B are negligible compared to the distance of separation.

(b) What is the force of repulsion if each sphere is charged double the above amount, and the distance between them is halved?

13: Suppose the spheres A and B in Exercise 1.12 have identical sizes. A third sphere of the same size but uncharged is brought in contact with the first, then brought in contact with the second, and finally removed from both. What is the new force of repulsion between A and B?

14: Figure 1.33 shows tracks of three charged particles in a uniform electrostatic field. Give the signs of the three charges. Which particle has the highest charge to mass ratio?

15: Consider a uniform electric field . (a) What is the flux of this field through a square of 10 cm on a side whose plane is parallel to the yz plane? (b) What is the flux through the same square if the normal to its plane makes a angle with the x-axis?

16: What is the net flux of the uniform electric field of Exercise 1.15 through a cube of side 20 cm oriented so that its faces are parallel to the coordinate planes?

17: Careful measurement of the electric field at the surface of a black box indicates that the net outward flux through the surface of the box is . (a) What is the net charge inside the box? (b) If the net outward flux through the surface of the box were zero, could you conclude that there were no charges inside the box? Why or Why not?

NCERT Solutions for Class 12 Physics

NCERT Solutions Class 12 Physics PDF (Download) Free from myCBSEguide app and myCBSEguide website. Ncert solution class 12 physics includes text book solutions from both part 1 and part 2. NCERT Solutions for CBSE Class 12 Physics have total 20 chapters. 12 Physics NCERT Solutions in PDF for free Download on our website. Ncert physics class 12 solutions PDF and physics ncert class 12 PDF solutions with latest modifications and as per the latest CBSE syllabus are only available in myCBSEguide

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