MEDIUM
Earn 100

How Heinrich Hertz discovered the existence of electromagnetic waves?

Important Questions on Development

EASY
Name an instrument based upon the wave like behaviour of electrons. Explain.
EASY
Calculate the de Broglie wavelength of an electron of kinetic energy 100 eV. Given m=9.1×10-31 kg, e=1.6×10-19 C, and h=6.62×10-34 Js.
EASY
Give the example of a particle which has zero rest mass and zero charge. 
EASY
The number of photons of frequency v present in energy E is:
EASY

What is the speed of a photon with respect to another photon if,

(a) the two photons are going in the same direction and

(b) they are going in the opposite direction.

MEDIUM
Write a note on the nature of light and its role in photosynthesis.
MEDIUM
The energy associated with light of which of the following colours is minimum:
HARD
A particle of mass M at rest decays into two particles of masses m1 and m2, having non-zero velocities. The ratio of the de Broglie wavelengths of the particles, λ1λ2 is
HARD
Can a photon be deflected by an electric field? By a magnetic field?
EASY
What is the name given to quanta of electromagnetic energy?
EASY
The idea of the quantum nature of light has emerged in an attempt to explain
HARD
In an old-fashioned television set, electrons are accelerated through a potential difference of 25.0 kV. What is the de-Broglie wavelength of such electrons? (Relativity is not needed.)
EASY
As per recent understanding light consists of:
EASY
Are matter waves electromagnetic? Why?
MEDIUM

A particle moves in a closed orbit around the origin, due to a force which is directed towards the origin. The de Broglie wavelength of the particle varies cyclically between two values λ1 and λ2 with λ1>λ2. Which of the following statements are true?

EASY
What potential difference must be applied to an electron microscope to produce an electron beam of wavelength 0.41 A0?
HARD
A silver ball of radius 4.8 cm is suspended by a thread in the vacuum chamber. UV light of wavelength 200 nm is incident on the ball for some time during which a total energy of 1×10-7 J falls on the surface. Assuming on an average one out of 103 photons incident is able to eject an electron, the potential on the sphere will be
MEDIUM
Two particles A1 and A2 of masses m1 and m2 m1>m2 have the same de Broglie wavelength. Then,
HARD
Explaining the concept of photon describe its various properties.
HARD
Discuss briefly the experiment conducted by Hertz to produce and detect electromagnetic wave.