TG EAMCET (EAPCET) Physics Multiple Choice Questions (MCQs)

121. The phenomenon of electron emission due to light is known as:

• a) Compton effect
• b) Photoelectric effect
• c) Scintillation
• d) X-ray emission

Answer: b) Photoelectric effect

122. According to Hertz's observation, when ultraviolet light is incident on a metal surface, it:

• a) Increases the potential of the metal surface
• b) Produces an electric current
• c) Causes a rise in temperature
• d) Reduces the resistance of the metal

Answer: b) Produces an electric current

123. In the experimental study of the photoelectric effect, the intensity of the light affects:

• a) The stopping potential
• b) The number of emitted electrons (photocurrent)
• c) The energy of emitted electrons
• d) The frequency of emitted electrons

Answer: b) The number of emitted electrons (photocurrent)

124. The photoelectric current is directly proportional to the:

• a) Frequency of incident light
• b) Potential applied
• c) Intensity of incident light
• d) Wavelength of incident light

Answer: c) Intensity of incident light

125. The Einstein photoelectric equation relates the kinetic energy of emitted electrons to:

• a) The frequency of the incident radiation
• b) The intensity of the incident radiation
• c) The wavelength of the incident radiation
• d) The angle of incidence of radiation

Answer: a) The frequency of the incident radiation

126. The wave nature of matter was explained by:

• a) Albert Einstein
• b) Niels Bohr
• c) Louis de Broglie
• d) Max Planck

Answer: c) Louis de Broglie

127. In the Davisson and Germer experiment, the electron beam showed diffraction, which proved:

• a) Electrons are waves
• b) Electrons are particles
• c) Electrons have no mass
• d) Electrons do not follow the wave-particle duality

Answer: a) Electrons are waves

128. According to Bohr's model of the hydrogen atom, the electron revolves in:

• a) A fixed orbit with a constant radius
• b) An elliptical orbit with varying radius
• c) A circular orbit with variable energy
• d) A spiral orbit with increasing velocity

Answer: a) A fixed orbit with a constant radius

129. The Franck-Hertz experiment demonstrated that:

• a) Electrons can be absorbed by atoms in discrete quantities
• b) Light can have both wave and particle nature
• c) Electrons are attracted to the nucleus of an atom
• d) Atomic spectra are continuous

Answer: a) Electrons can be absorbed by atoms in discrete quantities

130. The line spectra of the hydrogen atom can be explained by:

• a) Rutherford’s model
• b) Bohr’s model
• c) Heisenberg’s uncertainty principle
• d) Einstein’s theory of relativity

Answer: b) Bohr’s model