Advertisements
Advertisements
प्रश्न
A magnetic field can be produced by
विकल्प
a moving charge
a changing electric field
Neither of them
Both of them
उत्तर
Both of them
According to Ampere-Maxwell's Law, a magnetic field is produced due to the conduction current in a conductor and the displacement current. The conduction current is actually the motion of the charge. The displacement current is due to the changing electric field. The displacement current is given by `i_d = ∈_0 (dΦ_E)/dt` (∵ `Φ_E` is the electric flux).
Thus, the magnetic field is produced by the moving charge as well as the changing electric field.
APPEARS IN
संबंधित प्रश्न
A metal rod is placed along the axis of a solenoid carrying a high-frequency alternating current. It is found that the rod gets heated. Explain why the rod gets heated.
A compass needle is placed in the gap of a parallel plate capacitor. The capacitor is connected to a battery through a resistance. The compass needle
Electromagnetic waves are produced by
An electric field `vec E` and a magnetic field `vec B` exist in a region. The fields are not perpendicular to each other.
Consider the following two statements regarding a linearly polarised, plane electromagnetic wave :
(A) The electric field and the magnetic field have equal average values.
(B) The electric energy and the magnetic energy have equal average values.
A plane electromagnetic wave is incident on a material surface. The wave delivers momentum p and energy E.
An electromagnetic wave going through vacuum is described by
E = E0 sin (kx − ωt).
Which of the following is/are independent of the wavelength?
Show that the dimensions of the displacement current `∈_0 (d varphi_E)/dt` are that of an electric current .
Using B = µ0 H, find the ratio E0/H0 for a plane electromagnetic wave propagating through vacuum. Show that it has the dimensions of electric resistance. This ratio is a universal constant called the impedance of free space.
The magnetic field in a plane electromagnetic wave is given by
B = (200 µT) sin [(4.0 × 1015s−1)(t−x/c)].
Find the maximum electric field and the average energy density corresponding to the electric field.
The intensity of the sunlight reaching Earth is 1380 W m−2. Assume this light to be a plane, monochromatic wave. Find the amplitudes of electric and magnetic fields in this wave.
Electromagnetic waves are transverse in nature as evident by ______
An electromagnetic wave of frequency 5 GHz, is travelling in a medium whose relative electric permittivity and relative magnetic permeability both are 2. Its velocity in this medium is ______ × 107 m/s.
