NCERT solutions for class 12 physics chapter 2 Electrostatic Potential and Capacitance - This chapter is the continuation of chapter 1 electric charges and fields. Chapter 2 talks about potential due to different systems of charges and about capacitance and dielectrics. Solutions of NCERT for class 12 physics chapter 2 electrostatic potential and capacitance require certain concepts to be studied in the first chapter to solve questions. The CBSE NCERT solutions for class 12 physics chapter 2 electrostatic potential and capacitance are helpful in the preparation of board exam. The important derivations of the NCERT class 12 physics chapter 2 are potential and potential energy due to a dipole. Not only derivation and problems are important, the theory portion of dielectric and polarization is also important. The solutions for NCERT help students to perform well in exams. Some times in competitive exams like NEET and JEE Mains similar types of questions from NCERT solutions for class 12 physics NCERT chapter 2 electrostatic potential and capacitance are asked.
NCERT solutions for class 12 physics chapter 2 electrostatic potential and capacitance exercises:
2.1 Two charges and are located 16 cm apart. At what point(s) on the line joining the two charges is the electric potential zero? Take the potential at infinity to be zero.
Given, two charge particles
The separation between two charged particle
Now, let's assume the point P between two charged particles where the electric potential is zero is x meter away from and meter away from
The potential at point P :
Hence the point between two charged particles where the electric potential is zero lies 10cm away from and 6 cm away from
Now, Let's assume a point Q which is outside the line segment joining two charges and having zero electric potential .let the point Q lie r meter away from and (0.16+r) meter away from
So electric potential at point Q = 0
Hence the second point where the electric potential is zero is 24cm away from and 40cm away from
2.3 (a) Two charges and are placed at points A and B 6 cm apart. (a) Identify an equipotential surface of the system.
Given, 2 charges with charges and .
An equipotential plane is a plane where the electric potential is the same at every point on the plane. Here if we see the plane which is perpendicular to line AB and passes through the midpoint of the line segment joining A and B, we see that at every point the electric potential is zero because the distance of all the points from two charged particles is same. Since the magnitude of charges is the same they cancel out the electric potential by them.
Hence required plane is plane perpendicular to line AB and passing through the midpoint of AB which is 3cm away from both charges.
2.21 (a) Two charges –q and +q are located at points (0, 0, –a) and (0, 0, a), respectively.
(a) What is the electrostatic potential at the points (0, 0, z) and (x, y, 0) ?
1)electric potential at point (0,0,z)
Electric potential :
2) Since the point,(x,y,0) lies in the normal to the axis of the dipole, the electric potential at this point is zero.
2.21 (c) Two charges –q and +q are located at points (0, 0, –a) and (0, 0, a), respectively
(c) How much work is done in moving a small test charge from the point (5,0,0) to (–7,0,0) along the x-axis? Does the answer change if the path of the test charge between the same points is not along the x-axis?
Since point (5,0,0) is equidistance from both charges, they both will cancel out each other potential and hence potential at this point is zero.
Similarly, point (–7,0,0) is also equidistance from both charges. and hence potential at this point is zero.
Since potential at both the point is zero, the work done in moving charge from one point to other is zero. Work done is independent of the path.
2.31 (f) What meaning would you give to the capacitance of a single conductor?
There is no meaning in the capacitor with a single plate factually. but we give it meaning by assuming the second plate at infinity. Hence capacitance of a single conductor is the amount of change required to raise the potential of the conductor by one unit amount.
Chapter list for class 12 physics is given below-
Importance of NCERT solutions for class 12 physics chapter 2 electrostatic potential and capacitance in board exams:
The CBSE NCERT solutions for class 12 physics chapter 2 electrostatic potential and capacitance will help in securing a good score in board exam. On an average 4 to 6 % questions are asked from this chapter for the board exam. For JEE Main on an average 6% of questions are asked from electrostatics and for NEET exam 4 to 6% questions are asked from the unit electrostatics. The unit electrostatics contains the first two chapters of class 12 NCERT physics.