In the case of the photoelectric effect:

1.	Since photons are absorbed as single (discrete) units, there is no significant time delay in the emission of photoelectrons.
2.	According to Einstein, the critical frequency \(\nu_{0} =\dfrac{e\phi }{h},\) where \(\phi\) is the work function and \(h\) is Planck’s constant. When light with this frequency \((\nu_0)\) hits the material, it causes electrons to be ejected with the maximum possible kinetic energy.
3.	Only a small fraction of the incident photons succeed in ejecting photoelectrons, while the majority are absorbed by the system as a whole and generate thermal energy.
4.	The maximum kinetic energy of the electrons depends on the intensity of the radiation.

The correct graph between photoelectric current \((i)\) and intensity \((I)\) is:

1.		2.
3.		4.

An \(\alpha\text-\)particle moves in a circular path of radius \(0.83~\text{cm}\) in the presence of a magnetic field of \(0.25~\text{Wb/m}^2.\) The de-Broglie wavelength associated with the particle will be:
1. \(1~\mathring{A}\)
2. \(0.1~\mathring{A}\)
3. \(10~\mathring{A}\)
4. \(0.01~\mathring{A}\)

For photoelectric emission from certain metals, the cutoff frequency is \(\nu.\) If radiation of frequency \(2\nu\)$\mathrm{}$ impinges on the metal plate, the maximum possible velocity of the emitted electron will be:
(\(m\) is the electron mass)

When the energy of the incident radiation is increased by \(20\%\), the kinetic energy of the photoelectrons emitted from a metal surface increases from \(0.5~\text{eV}\) to \(0.8~\text{eV}\). The work function of the metal is:
1. \(0.65~\text{eV}\)
2. \(1.0~\text{eV}\)
3. \(1.3~\text{eV}\)
4. \(1.5~\text{eV}\)