19. The charge per unit length of the four quadrant of 23. the ring is 22.-21, 2 and respectively. The clectric field at the centre is - 2 (A)- -i 27,R 2. j (B) 276,R 122 (C) 2,R (D) None

The charge per unit length of the four quadrant of the ring is 2 lambda, -2lambda, lambda and -lambda respectively. The electric field at the centre is:

The charge per unit length of the four quadrant of the ring is 2 lambda, -2lambda, lambda and -lambda respectively. The electric field at the centre is:

The charge per unit length of the four quadrant of the ring is 2 lambda, -2lambda, lambda and -lambda respectively. The electric field at the centre is:

A half ring of radius R has a charge of lambda per unit length. The electric force on 1C charged placed at the center is

There are three concentric thin spheres of radius a,b,c (agtbgtc) . The total surface charge densities on their surfaces are sigma,-sigma,sigma respectively. The magnitude of the electric field at r (distance from centre) such that agtrgtb is: A. 0 B. (sigma)/(epsilon_(0) r^(2))(b^(2)-c^(2)) C. (sigma)/(epsilon_(0)r)(a^(2)+b^(2)) D. none of these

The order and degree of the differential equation of the family of circles of fixed radius r with centres on the y-axis, are respectively a) 2,2 b) 2,3 c) 1,1 d) 1,2

A nonconducting ring of radius R has uniformly distributed positive charge Q. A small part of the ring.of length d, is removed (d lt lt R) . The electric field at the centre of the ring will now be