IIT JEE , AIEEE Forum - Physics , Electricity - h. c. verma ch.GAUSS LAW pls solve with steps Qno. 19 & 20 ITS URGENT!!!!!

pavann

h. c. verma ch.GAUSS LAW pls solve with steps Qno. 19 & 20 ITS URGENT

pavann

plz help

ganesha1991

its easy mann
see E=sigma/2e0
now theere will be force horizontal on the ball F=Eq
and mg and T
solve it using the newtons laws of motion and find sigma

krish1092

19)Mass of the ball = 10g

Charge = 4 x 10^-6 C

Thread length = 10cm

From the figure,Tcos $\theta$ =mg

Tsin $\theta$ = $\frac{\sigma q}{2\epsilon_0}$ [electric force]

Tcos $\theta$ =mg

Dividing the 2 equations,we get

Tan $\theta$ = $\frac{\sigma q}{2mg\epsilon_0}$

$\Longrightarrow \sigma=\frac{2mg\epsilon_0 tan\theta}{q}$

Now substitute the values to get the anwer.

For figure:

http://imaginationcubed.com/loader.php?aDrawingID=1ebd86951361759142fd7ddaf6caf721&from_email=krish1092@rediffmail.com&from_name=krish

rate me if useful

krish1092

20(a) Tension in the string in Equilibrium

T cos 60° = mg

$T=\frac{mg}{cos60}$

=10 x 10^-3 x 10 / (1/2)

=0.2 N

Ask & Discuss Questions with Community & Experts

19)Mass of the ball = 10g

Charge = 4 x 10-6 C