Two similarly and equally charged identical metal spheres A and B repel each other with a force of 2 . 0 × 10 - 5 N . A third identical, uncharged sphere C is touched with A and then placed at the mid-point between A and B . What is net electric force on C ?

In first condition, q 1 = q 2 = q Force of repulsion = F = 2 . 0 × 10 - 5 N F = 1 4 π ϵ 0 · q 2 r 2 = 9 × 10 9 q 2 r 2 q 2 r 2 = 2 × 10 - 5 9 × 10 9 = 2 9 × 10 - 14 When uncharged sphere C touched with A , then charge on A and C = q + 0 2 = q 2 Now C , is placed at middle of A and B F net at sphere C = F eA - F eB = 1 4 π ε 0 . q 2 · q 2 ( r / 2 ) 2 - 1 4 π ϵ 0 · q · q / 2 ( r / 2 ) 2 = 1 4 π ϵ 0 · q 2 × 4 4 r 2 - 1 4 π ϵ 0 · q 2 × 4 2 r 2 = 1 4 π ε 0 · q 2 r 2 [ 1 - 2 ] = - 1 4 π ε 0 · q 2 r 2 = - 2 . 0 × 10 - 5 N Magnitude of net force = 2 . 0 × 10 - 5 N - ve sign indicates that direction will be opposite to B mean towards A

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Three charges $- 1, 2$ and $3$ micro coulomb are placed respectively at the corners A, B and C of an equilateral triangle of side $200 cm$ . Calculate the field intensity at a point P which is half-way along BC.

Important Questions on Interaction of Charged Particles, Electric Field and Potential

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12th West Bengal Board

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A Text Book of PHYSICS PART 2 : CLASS 12>Chapter 2 - Interaction of Charged Particles, Electric Field and Potential>EXERCISE 2>Q 15

Two similarly and equally charged identical metal spheres

A

and

B

repel each other with a force of

2.0 \times 10^{- 5} N

. A third identical, uncharged sphere

C

is touched with

A

and then placed at the mid-point between

A

and

B

. What is net electric force on

C

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12th West Bengal Board

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A Text Book of PHYSICS PART 2 : CLASS 12>Chapter 2 - Interaction of Charged Particles, Electric Field and Potential>EXERCISE 2>Q 16

The points A, B and C from an equilateral triangle of side a. Point charges of equal magnitude q esu are placed at A and B. Find the electric field strength and potential at C due to these charges when (i) both charges are positive and

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12th West Bengal Board

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A Text Book of PHYSICS PART 2 : CLASS 12>Chapter 2 - Interaction of Charged Particles, Electric Field and Potential>EXERCISE 2>Q 16

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12th West Bengal Board

IMPORTANT

A Text Book of PHYSICS PART 2 : CLASS 12>Chapter 2 - Interaction of Charged Particles, Electric Field and Potential>EXERCISE 2>Q 17

Two charges of

+ 1 μ C

and

- 1 μ C

are placed at the corners of the base of an equilateral triangle. The length of the side of the triangle is

0.7 m

. Find the electric field intensity at the apex of the triangle.

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12th West Bengal Board

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A Text Book of PHYSICS PART 2 : CLASS 12>Chapter 2 - Interaction of Charged Particles, Electric Field and Potential>EXERCISE 2>Q 18

Three charges

q, q

and

- q

are placed at the three vertices of an equilateral triangle of side a. Calculate the potential energy of the system

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A Text Book of PHYSICS PART 2 : CLASS 12>Chapter 2 - Interaction of Charged Particles, Electric Field and Potential>EXERCISE 2>Q 19

Two identical conducting spheres, having charges of opposite sign attract each other with a force of

0.108 N,

when separated by

0.5 m

. The spheres are now connected by a conducting wire. When the wire is removed, spheres repel each other with a force of

0.036 N

. What were the initial charges on the spheres?

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12th West Bengal Board

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A Text Book of PHYSICS PART 2 : CLASS 12>Chapter 2 - Interaction of Charged Particles, Electric Field and Potential>EXERCISE 2>Q 20

Two identically charged small metal spheres each of mass

20 gm

are suspended from a point by thread of length

1 m

. The threads make angle

45 °

with the vertical. Find the charge on each sphere.

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12th West Bengal Board

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A Text Book of PHYSICS PART 2 : CLASS 12>Chapter 2 - Interaction of Charged Particles, Electric Field and Potential>EXERCISE 2>Q 21

Three identical small spheres weighing

0.1 gm

are suspended from a point with silk threads each having length

20 cm

. What charges should be imparted to the spheres so that each thread makes an angle

30 °

to the vertical? Assume the charges to be equal.

Three charges -1,2 and 3 micro coulomb are placed respectively at the corners A, B and C of an equilateral triangle of side 200 cm. Calculate the field intensity at a point P which is half-way along BC.

Important Questions on Interaction of Charged Particles, Electric Field and Potential

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Three charges $- 1, 2$ and $3$ micro coulomb are placed respectively at the corners A, B and C of an equilateral triangle of side $200 cm$ . Calculate the field intensity at a point P which is half-way along BC.