51 - Electric Field and Potential Questions Answers
Initially the spheres a and b are at potential be a and b respectively now sphere b is earthd by closing the switch the poential of a will become
No meaning can be incurred by this language. Rectify it for getting answer
A particle a having a charge of 5.0×10
is fixed in. a vertical wall. A second particle B of mass 100 g and. having equal charge is supended by a silk thread. of length 30 cm form the wall. The point of suspension is. 30 cm above the particle A. Find the angle of the thread. with the vertical when it stays in equilibrium.
A Volt-meter of 20000 Ohm resistance is connected with R ohm resistance in series. if we apply 110 V of pd to the mechanism, the Volt meter shows 5 V reading.. so find the R...
current on both the resistances will be same
so V1/R1 = V2/R2
5/20000 = 105/R
solve
An isolated conducting sphere of radius r has given charge q then PE??
ans is q2/8πe0r
But Sir ,why the ans q2/2πe0r is incorrect??
let we have given x charge and want to give dx also to the sphere
so dE = [1/4πε0]xdx/r
now integrate and take limits of x as 0 to q
2 Equal -ve charges -q r placed at pt(0,a) and (o,-a) on y axis , one +ve charge +q at rest is left from pt(2a,0). this charge will not execute SHM . WHY?? even when F α -x condition is satisfying as force is due to both charges is acting & motion is also opposing during oscillating
Solve the question for force, you will get a condition according to which yours statement "even when F α -x condition is satisfying"
is incorrect
Two identical particles each of mass M & charge Q are placed some distance apart . If they are in equilm under mutual gravitational & electric force then calculate the order of signature of charge Q/M in SI system.
ANS = 10-10 C/kg
on comparing gravitational force and electrical force,
we get 9*109 * q2/r2 = 6.67*10-11* m2/r2
so q/m = 10-10 approx
a fixed uniformly charged ring of radius 3m has a positive linear charge density 50/3µC/m. a point charge 5μC is moving towards the ring along its axis such that its kinetic energy 4m away is 5J. Its kinetic energy at the centre of the ring will be?
compare total energy at the two points and get answer