Home
Class 11
PHYSICS
Charges +q and -q are located at the cor...

Charges `+q and `-q` are located at the corners of a cube of side as shown in (Fig. 3.117). Find the work done to separate the charges to infinite distance.
.

Text Solution

Verified by Experts

The correct Answer is:
`W=5.824[q/(4pi in_(0) a)]`
For potential energy of the system of charges total number of charge pairs will be `.^(8)C_(2)` or `28` of these `28` pairs 12 unlike charges are at a separation a, `12` like charges are at a `sqrt(2)` a and `4` unlike charges are at separation `sqrt(3)a`. Therefore, the potential energy of the system.
`U = (1)/(4pi epsilon_(0)) [((12)(q)(-q))/(a)+((12)(q)(q))/(sqrt(2)a)+((4)(q)(-q))/(sqrt(3)a)]`
`= - 5.824 ((1)/(4pi epsilon_(0)).(q^(2))/(a))`
The binding energy of this system is therefore,
`|U| = 5.824((1)/(4pi epsilon_(0))(q^(2))/(a))`
So, work done by external forces in diassembling, this system of charges is
`W = 5.824 ((1)/(4 pi epsilon_(0)).(q^(2))/(a))`
Promotional Banner

Topper's Solved these Questions

  • MISCELLANEOUS

    ALLEN|Exercise PHY|68 Videos

  • MISCELLANEOUS

    ALLEN|Exercise EXERCISE-1|120 Videos

  • MISCELLANEOUS

    ALLEN|Exercise LINKED COMPREHENSION TYPE|3 Videos

  • KINEMATICS (MOTION ALONG A STRAIGHT LINE AND MOTION IN A PLANE)

    ALLEN|Exercise BEGINNER S BOX-7|8 Videos

  • PHYSICAL WORLD, UNITS AND DIMENSIONS & ERRORS IN MEASUREMENT

    ALLEN|Exercise EXERCISE-IV|8 Videos

Similar Questions

Explore conceptually related problems

Charges +q and -q are located at the corners of a cube of side as show in the figure. Find the work done to separate the charges to infinite distance

Three identical dipoles with charges q and -q , and separation A between the charges, are placed at the corners of an equilateral triangle of side D as shown in (Fig. 3.123). Find the interaction energy of the system (a lt lt d) . .

Point charges +q and -q are kept alternately at the corners of a cube of side 'a' as shown in the figure. Write an expression for the work done in removing all the charges far away from each other.

Four charges are arranged at the corners of a square ABCD of side d, as shown in Fig. Find the work required to put together this arrangement (b) A charge q_(0) brought to the center E of the square, the four charges being held fixed at the corners . How much extra work in needed to do this ?

Four point charges Q, q, Q and q are placed at the corners of a square of side' a' as shown in the figure. Find the . (a) resultnat electric force on a charge Q and . (b) potential energy of this system.

Three points charges of 1 C, 2C and 3C are placed at the corners of an equilateral triangle of side 100 cm. Find the work done to move these charges to the corners of a similar equilateral triangle of side 50 cm.

Three points charges of 1 C, 2C and 3C are placed at the corners of an equilateral triangle of side 100 cm. Find the work done to move these charges to the corners of a similar equilateral triangle of side 50 cm.

Four charges of +q, +q, +q and +q are placed at the corners A, B, C and D of a square of side a. Find the resultant force on the charge at D

(a) Three point charges q,-4q and 2q are placed at the vertices of an equilateral triangle ABC of side 'l' as shown in the figure. Obtain the expression for the magnitude of the resultant electric force acting on the charge q. (b) Find out the amount of the work 4one to separate the charges at infinite distance.

Four identical charges q are placed at the corners of a square of side a. Find the potential energy of one of the charges due to the remaining charges. .