Explore popular questions from Dual Nature of Matter and Radiation for JEE Advanced. This collection covers Dual Nature of Matter and Radiation previous year JEE Advanced questions hand picked by experienced teachers.

Physics
Chemistry
Mathematics
Q 1.

Correct4

Incorrect-1

The potential difference applied to an {tex} X {/tex}-ray tube is {tex} V {/tex}. The ratio of the de Broglie wavelength of electron to the minimum wavelength of {tex} X {/tex}-ray is directly proportional to

A

{tex} V {/tex}

{tex} \sqrt { V } {/tex}

C

{tex} V ^ { 3 / 2 } {/tex}

D

{tex} V ^ { 7 / 2 } {/tex}

##### Explanation

Q 2.

Correct4

Incorrect-1

Two identical photocathodes receive light of frequencies {tex} f _ { 1 } {/tex} and {tex} f _ { 2 } . {/tex} If the velocities of the photoelectrons (of mass {tex} m {/tex} ) coming out are {tex} v _ { 1 } {/tex} and {tex} v _ { 2 } , {/tex} respectively, then

A

{tex} v _ { 1 } - v _ { 2 } = \left[ \frac { 2 h } { m } \left( f _ { 1 } - f _ { 2 } \right) \right] ^ { 1 / 2 } {/tex}

{tex} v _ { 1 } ^ { 2 } - v _ { 2 } ^ { 2 } = \frac { 2 n } { m } \left( f _ { 1 } - f _ { 2 } \right) {/tex}

C

{tex} v _ { 1 } + v _ { 2 } = \left[ \frac { 2 h } { m } \left( f _ { 1 } - f _ { 2 } \right) \right] ^ { 1 / 2 } {/tex}

D

{tex} v _ { 1 } ^ { 2 } + v _ { 2 } ^ { 2 } = \frac { 2 h } { m } \left( f _ { 1 } - f _ { 2 } \right) {/tex}

##### Explanation

Q 3.

Correct4

Incorrect-1

Light of wavelength {tex} \lambda {/tex} from a small {tex} 0.5 \mathrm { mW } {/tex} He-Ne laser source, used in the school laboratory, shines from a spacecraft of mass {tex} 1000 \mathrm { kg } {/tex}. Estimate the time needed for the spacecraft to reach a velocity of {tex} 1.0 \mathrm { km } s ^ { - 1 } {/tex}
from rest. The momentum {tex} p {/tex} of a photon of wavelength {tex} \lambda {/tex} is given by {tex} p = h / \lambda , {/tex} where {tex} h {/tex} is Plank's constant

A

{tex} 6 \times 10 ^ { 18 } {/tex}

B

{tex} 3 \times 10 ^ { 17 } {/tex}

{tex} 6 \times 10 ^ { 17 } {/tex}

D

{tex} 2 \times 10 ^ { 15 } {/tex}

##### Explanation

Q 4.

Correct4

Incorrect-1

The binding energy of the innermost electron in tungsten is {tex}40 keV{/tex}. To produce characteristic X-rays using a tungsten target in an X-rays tube the potential difference V between the cathode and the anti-
cathode should be

A

{tex} V < 40\ k V {/tex}

B

{tex} V \leq 40\ k V {/tex}

{tex} V > 40 \ k V {/tex}

D

{tex} V > / < 40\ k V {/tex}

##### Explanation

Q 5.

Correct4

Incorrect-1

A particle of mass {tex} ^ { \prime } m ^ { \prime } {/tex} is projected from ground with velocity {tex}'u'{/tex} making angle {tex}'\theta'{/tex} with the vertical. The de Broglie wavelength of the particle at the highest point is

A

{tex} \infty {/tex}

{tex} h / m u \sin \theta {/tex}

C

{tex} h / m u \cos \theta {/tex}

D

{tex} h / m u {/tex}

##### Explanation

Q 6.

Correct4

Incorrect-1

The radius of second orbit of an electron in hydrogen atom is 2.116 Å. The de Broglie wavelength associated with this electron in this orbit would be

{tex} 6.64 \mathrm { Å } {/tex}

B

{tex} 1.058 \mathrm { Å } {/tex}

C

{tex} 2.116 \mathrm { Å } {/tex}

D

{tex} 13.28 \mathrm { Å } {/tex}

##### Explanation

Q 7.

Correct4

Incorrect-1

A small mirror of mass {tex} m {/tex} is suspeneded by a light thread of length {tex} \ell . {/tex} A short pulse of laser falls on the mirror with energy {tex} E . {/tex} Then, which of the following statement is correct?

A

If the pulse falls normally on the mirror, it deflects by {tex} \theta = 2 E / ( m c \sqrt { 2 g \ell } ) {/tex}

B

If the pulse falls normally on the mirror, it deflects by {tex} \theta = 2 E / ( m c \sqrt { 2 \mathrm { g } } {/tex} )

Impulse in thread depends on angle at which the pulse falls on the mirror

D

None of the above

##### Explanation

Q 8.

Correct4

Incorrect-1

A cesium photocell, with a steady potential difference of {tex} 60 \mathrm { V } {/tex} across it, is illuminated by a small bright light placed {tex} 1 \mathrm { m } {/tex} away. When the same light is placed {tex} 2 \mathrm { m } {/tex} away, the electrons crossing the photocell

A

Each carry one-quarter of their previous momentum

B

Each carry one-quarter of their previous energy

Are one-quarter as numerous

D

Are half as numerous

##### Explanation

Q 9.

Correct4

Incorrect-1

Given that a photon of light of wavelength {tex} 10,000 Å{/tex} has an energy equal to {tex}1.23 eV{/tex}. When light of wavelength {tex}5000 Å{/tex} and intensity {tex} I _ { 0 } {/tex} falls on a photoelectric cell, the saturation current is {tex} 0.40 \times 10 ^ { - 6 } \mathrm { A } {/tex} and
the stopping potential is {tex} 1.36 \mathrm { V } , {/tex} if the intensity of light is made {tex} 4 I _ { 0 } , {/tex} then the saturation current will become

A

{tex} 0.40 \times 1 \mu \mathrm { A } {/tex}

B

{tex} 0.40 \times 2 \mu \mathrm { A } {/tex}

{tex} 0.40 \times 4 \mu \mathrm { A } {/tex}

D

{tex} 0.40 \times 8 \mu \mathrm { A } {/tex}

##### Explanation

Q 10.

Correct4

Incorrect-1

All electrons ejected from a surface by incident light of wavelength {tex} 200 \mathrm { nm } {/tex} can be stopped before travelling {tex} 1 \mathrm { m } {/tex} in the direction of a uniform electric field of {tex} 4 \mathrm { NC } ^ { - 1 } . {/tex} The work function of the surface is

A

{tex} 4 \mathrm { eV } {/tex}

B

{tex} 6.2 \mathrm { eV } {/tex}

C

{tex} 2 \mathrm { eV } {/tex}

{tex} 2.2 \mathrm { eV } {/tex}