Advertisements
Advertisements
Question
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.
Solution
The magnetic field along the axis of a solenoid carrying a high-frequency alternating current changes continuously. Due to the change in the magnetic field, e.m.f (or eddy current) is induced in the metal rod. There will be flow of charge due to the induced e.m.f. The direction of the induced e.m.f changes very frequently due to the high-frequency alternating current in the solenoid. Thus, the rod gets heated up due to the flow of charge in it.
APPEARS IN
RELATED QUESTIONS
A magnetic field can be produced by
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
Dimensions of 1/(µ0ϵ0) is
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 free electron is placed in the path of a plane electromagnetic wave. The electron will start moving
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.
