1
JEE Main 2022 (Online) 26th June Evening Shift
MCQ (Single Correct Answer)
+4
-1
Change Language

A metal surface is illuminated by a radiation of wavelength 4500 $$\mathop A\limits^o $$. The ejected photo-electron enters a constant magnetic field of 2 mT making an angle of 90$$^\circ$$ with the magnetic field. If it starts revolving in a circular path of radius 2 mm, the work function of the metal is approximately :

A
1.36 eV
B
1.69 eV
C
2.78 eV
D
2.23 eV
2
JEE Main 2022 (Online) 26th June Morning Shift
MCQ (Single Correct Answer)
+4
-1
Change Language

An electron with speed v and a photon with speed c have the same de-Broglie wavelength. If the kinetic energy and momentum of electron are Ee and pe and that of photon are Eph and pph respectively. Which of the following is correct?

A
$${{{E_e}} \over {{E_{ph}}}} = {{2c} \over v}$$
B
$${{{E_e}} \over {{E_{ph}}}} = {v \over {2c}}$$
C
$${{{p_e}} \over {{p_{ph}}}} = {{2c} \over v}$$
D
$${{{p_e}} \over {{p_{ph}}}} = {v \over {2c}}$$
3
JEE Main 2022 (Online) 25th June Evening Shift
MCQ (Single Correct Answer)
+4
-1
Change Language

A proton, a neutron, an electron and an $$\alpha$$ particle have same energy. If $$\lambda$$p, $$\lambda$$n, $$\lambda$$e and $$\lambda$$a are the de Broglie's wavelengths of proton, neutron, electron and $$\alpha$$ particle respectively, then choose the correct relation from the following :

A
$$\lambda$$p = $$\lambda$$n > $$\lambda$$e > $$\lambda$$a
B
$$\lambda$$a < $$\lambda$$n < $$\lambda$$p < $$\lambda$$e
C
$$\lambda$$e < $$\lambda$$p = $$\lambda$$n > $$\lambda$$a
D
$$\lambda$$e = $$\lambda$$p = $$\lambda$$n = $$\lambda$$a
4
JEE Main 2022 (Online) 25th June Morning Shift
MCQ (Single Correct Answer)
+4
-1
Out of Syllabus
Change Language

Given below are two statements :

Statement I : Davisson-Germer experiment establishes the wave nature of electrons.

Statement II : If electrons have wave nature, they can interfere and show diffraction.

In the light of the above statements choose the correct answer from the option given below :

A
Both Statement I and Statement II are true.
B
Both Statement I and Statement II are false.
C
Statement I is true but Statement II is false.
D
Statement I is false but Statement II is true.
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