Explanation:
As the current is flowing through a conductor so it it is distributed only on the surface of the conductor not in the volume of the cylindrical conductor. It is equivalent to charge distribution on a cylindrical sheet for which electric field inside a conducting cylindrical sheet is always zero.
Magnetic fields at any point inside the conducting cylinder is proportional to the distance from the axis of the cylinder.
At the axis, r = 0.
This implies that field will be zero at the axis.
Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.
A 50 turns circular coil has a radius of 3 cm, it is kept in a magnetic field acting normal to the area of the coil. The magnetic field B increased from 0.10 tesla to 0.35 tesla in 2 milliseconds. The average induced e.m.f. in the coil is
|
(a) 1.77 volts |
(b) 17.7 volts |
(c) 177 volts |
(d) 0.177 volts |
The wavelength of emission line spectrum and absorption line spectrum of a substance are related as
|
(a) Absorption has larger value |
(b) Absorption has smaller value |
|
(c) They are equal |
(d) No relation |
Equipotential surfaces are shown in figure. Then the electric field strength will be
|
(a) 100 Vm–1 along X-axis |
(b) 100 Vm–1 along Y-axis |
|
(c) 200 Vm–1 at an angle 120o with X-axis |
(d) 50 Vm–1 at an angle 120o with X-axis |
A charge Q is divided into two parts of q and Q - q. If the coulomb repulsion between them when they are separated is to be maximum, the ratio of 
should be
|
(a) 2 |
(b) 1/2 |
(c) 4 |
(d) 1/4 |
Between the plates of a parallel plate capacitor a dielectric plate is introduced just to fill the space between the plates. The capacitor is charged and later disconnected from the battery. The dielectric plate is slowly drawn out of the capacitor parallel to the plates. The plot of the potential difference across the plates and the length of the dielectric plate drawn out is
|
(a)
|
(b)
|
(c)
|
(d)
|
