1
JEE Main 2024 (Online) 29th January Morning Shift
+4
-1

The de-Broglie wavelength of an electron is the same as that of a photon. If velocity of electron is $$25 \%$$ of the velocity of light, then the ratio of K.E. of electron and K.E. of photon will be:

A
$$\frac{1}{4}$$
B
$$\frac{8}{1}$$
C
$$\frac{1}{8}$$
D
$$\frac{1}{1}$$
2
JEE Main 2024 (Online) 27th January Evening Shift
+4
-1

The threshold frequency of a metal with work function $$6.63 \mathrm{~eV}$$ is :

A
$$16 \times 10^{15} \mathrm{~Hz}$$
B
$$16 \times 10^{12} \mathrm{~Hz}$$
C
$$1.6 \times 10^{15} \mathrm{~Hz}$$
D
$$1.6 \times 10^{12} \mathrm{~Hz}$$
3
JEE Main 2023 (Online) 15th April Morning Shift
+4
-1
The de Broglie wavelength of an electron having kinetic energy $\mathrm{E}$ is $\lambda$. If the kinetic energy of electron becomes $\frac{E}{4}$, then its de-Broglie wavelength will be :
A
$\sqrt{2} \lambda$
B
$2 \lambda$
C
$\frac{\lambda}{2}$
D
$\frac{\lambda}{\sqrt{2}}$
4
JEE Main 2023 (Online) 13th April Evening Shift
+4
-1

Given below are two statements:

Statement I : Out of microwaves, infrared rays and ultraviolet rays, ultraviolet rays are the most effective for the emission of electrons from a metallic surface.

Statement II : Above the threshold frequency, the maximum kinetic energy of photoelectrons is inversely proportional to the frequency of the incident light.

In the light of above statements, choose the correct answer form the options given below

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