The electric field in a region is radially outward and varies with distance r as `E = 250 r Vm^-2` Calculate the charge contained in a sphere of radius 0.2 m centred at the origin.

The magnitude of electric field (in NC^-1) in a region varies with the distance r (in m) as E=10 r+5. By how much will be the electric potential increased in moving from point at r=1 m to a point at r=10 m ?

Electric field inside a sphere varies with distance as A r. Find the total charge enclosed within the sphere, if A = 3,000 V m^-2 and R = 30 cm, where R is radius of the sphere.

The electric potential V(x) in a region along the X-axis varies with the distance x (in metre) according to the relation V(x) = 4x^2 . Calculate the force experienced by a 1muC charge placed at point x = 1 m.

A magnetic field in a certain region is given by bar B = B_0 cos omegathatk and a coil of radius a with resistanc R is placed i the XY-plane with its centre at the origin in the magnetic field as shown in the figure. Find the magnitude and direction of current at (a,0,0) at t = pi//2 omega

A uniformly charged conducting sphere of 2.5 m in diameter has a surface charge density of 100 muC/m^2 . Calculate the charge on the sphere.

How does electric field at a point change with distance r from an infinitely long charged wire?

A bar magnet of length 0.1 m has a pole strength of 50 A m. Calculate the magnetic field at distance of 0.2 m from tis centre on its equitorial line.

The electric field at a distance 3R/2 from the centre of a charge conducting spherical shell of radius R is E. The electric field at a distance R/2 from the centre of the sphere is