The work function of a metal is 4.2 eV, its threshold wavelength will be
(a) 4000 Å                    (b) 3500 Å
(c) 2955 Å                    (d) 2500 Å

Concept Questions :-

Photoelectric effect experiment
High Yielding Test Series + Question Bank - NEET 2020

Difficulty Level:

The number of photo-electrons emitted per second from a metal surface increases when

(a) The energy of incident photons increases

(b) The frequency of incident light increases

(c) The wavelength of the incident light increases

(d) The intensity of the incident light increases

Concept Questions :-

Photoelectric effect experiment
High Yielding Test Series + Question Bank - NEET 2020

Difficulty Level:

The work function of metal is 1 eV. Light of wavelength 3000 Å is incident on this metal surface. The velocity of emitted photo-electrons will be
(a) 10 m/sec                           (b) $1×{10}^{3}$ m/sec
(c) $1×{10}^{4}$ m/sec                     (d) $1×{10}^{6}$ m/sec

Concept Questions :-

Einstein photo-electric equation
High Yielding Test Series + Question Bank - NEET 2020

Difficulty Level:

The work function of a metal is $1.6×{10}^{-19}$ J. When the metal surface is illuminated by the light of wavelength 6400 Å, then the maximum kinetic energy of emitted photo-electrons will be
(Planck's constant =
(a)                  (b)
(c)                 (d)

Concept Questions :-

Einstein photo-electric equation
High Yielding Test Series + Question Bank - NEET 2020

Difficulty Level:

Ultraviolet radiations of 6.2 eV falls on an aluminium surface (work function 4.2 eV ). The kinetic energy in joules of the fastest electron emitted is approximately

(a) $3.2×{10}^{-21}$              (b) $3.2×{10}^{-19}$
(c) $3.2×{10}^{-17}$              (d) $3.2×{10}^{-15}$

Concept Questions :-

Einstein photo-electric equation
High Yielding Test Series + Question Bank - NEET 2020

Difficulty Level:

The work function for tungsten and sodium are 4.5 eV and 2.3 eV respectively. If the threshold wavelength $\mathrm{\lambda }$ for sodium is 5460 Å, the value of $\mathrm{\lambda }$ for tungsten is

(a) 5893 Å                   (b) 10683 Å
(c) 2791 Å                   (d) 528 Å

Concept Questions :-

Photoelectric effect experiment
High Yielding Test Series + Question Bank - NEET 2020

Difficulty Level:

A photon of energy 3.4 eV is incident on a metal having work function 2 eV. The maximum K.E. of photo-electrons is equal to
(a) 1.4 eV                   (b) 1.7 eV
(c) 5.4 eV                   (d) 6.8 eV

Concept Questions :-

Einstein photo-electric equation
High Yielding Test Series + Question Bank - NEET 2020

Difficulty Level:

The photoelectric threshold wavelength for a metal surface is 6600 Å. The work function for this is
(a) 1.87 V                              (b) 1.87 eV
(c) 18.7 eV                             (d) 0.18 eV

Concept Questions :-

Photoelectric effect experiment
High Yielding Test Series + Question Bank - NEET 2020

Difficulty Level:

Photoelectric effect was successfully explained first by
(a) Planck                (b) Hallwash
(c) Hertz                  (d) Einstein

Concept Questions :-

Photoelectric effect experiment
High Yielding Test Series + Question Bank - NEET 2020

Difficulty Level:

The spectrum of radiation $1.0×{10}^{14}$ Hz is in the infrared region. The energy of one photon of this in joules will be

(a) $6.62×{10}^{-48}$              (b) $6.62×{10}^{-20}$
(c)  $\frac{6.62}{3}×{10}^{-28}$            (d) $3×6.62×{10}^{-28}$

Concept Questions :-

De-broglie wavelength