Question

Tow equally charged identical pith balls are suspended by identical massless strings.if this set up is on mercury(g=3.7m/s2),earth(g=9.8m/s2)
and jupiter(g=24.5m/s2),then angle
2 theta will be

Options
(A) Maximum on mercury.

(B) Maximum on earth,as it has atmosphere.

(C) Maximum on jupiter.

(D)The same on any planet as coulomb is independent of gravity.

Answer 1

did u gave iapt exam

Answer 2

Let m is the mass of each ball and balls are suspended from a common point by two strings of equal length L, at equilibrium condition angle between stings is 2θ as shown in figure.

at equilibrium ,

Tcosθ = mg

And , Tsinθ = Kq²/r² ,where r = 2Lsinθ

∴ Tsinθ/Tcosθ = Kq²/r²mg

⇒tanθ = Kq²/(2Lsinθ)²mg

⇒ m = kq²/{4L²sin²θ × tanθ × g}

= Kq²cosθ/4L²sin³θg

Let suppose theta be 60

So =kq^2cos60/4L^2sin^3theta×g on earth

So by trying all these g on mercury and Jupiter 2theta will be maximum on jupiter