Two small balls having equal poistive charges Q( coulomb) on each are suspended by two insulating strings of equal length L(metre) from a hook fixed to a stand. The whole set up is taken in a satellite into space where there is no gravity (state of weightlessness). The angle between the two strings is...............and the tenison in each string is...................newtons.

Options

A. `180^(@),(1)/(4piepsi_(0))(q^(2))/((2l)^(2))N`
B. `90^(@),(1)/(4piepsi_(0))(q^(2))/(l^(2))N`
C. `180^(@),(1)/(4piepsi_(0))(q^(2))/(2l^(2))N`
D. `180^(@),(1)/(4piepsi_(0))(q^(2))/(l^(2))N`

Answer

A

Explanation

The two suspended balls have equal +ve charges. Hence there will be a force of repulsion between them. On the surface of the earth, the weight mg acts on the ball. But in the gravity free space I the satellite, g=0 and mg=0. hence the two strings will become horizontal due to repulsion and the angle between them will be `180^(@)`, but tension (T) is not equal to O.
T=Electrostatic force of repusion`=(1)/(4piepsi_(0))(q^(2))/((2l)^(2))N`