1
JEE Main 2025 (Online) 22nd January Morning Shift
MCQ (Single Correct Answer)
+4
-1
Change Language

The work functions of cesium (Cs) and lithium (Li) metals are 1.9 eV and 2.5 eV , respectively. If we incident a light of wavelength 550 nm on these two metal surfaces, then photo-electric effect is possible for the case of

A
 Both Cs and Li
B
Neither Cs nor Li
C
Li only
D
Cs only
2
JEE Main 2025 (Online) 22nd January Morning Shift
MCQ (Single Correct Answer)
+4
-1
Change Language

An electron in the ground state of the hydrogen atom has the orbital radius of $5.3 \times 10^{-11} \mathrm{~m}$ while that for the electron in third excited state is $8.48 \times 10^{-10} \mathrm{~m}$. The ratio of the de Broglie wavelengths of electron in the ground state to that in the excited state is

A
4
B
3
C
9
D
16
3
JEE Main 2024 (Online) 9th April Evening Shift
MCQ (Single Correct Answer)
+4
-1
Change Language

UV light of $$4.13 \mathrm{~eV}$$ is incident on a photosensitive metal surface having work function $$3.13 \mathrm{~eV}$$. The maximum kinetic energy of ejected photoelectrons will be:

A
4.13 eV
B
1 eV
C
7.26 eV
D
3.13 eV
4
JEE Main 2024 (Online) 9th April Morning Shift
MCQ (Single Correct Answer)
+4
-1
Change Language

A proton, an electron and an alpha particle have the same energies. Their de-Broglie wavelengths will be compared as :

A
$$\lambda_{\mathrm{p}}>\lambda_{\mathrm{e}}>\lambda_\alpha$$
B
$$\lambda_\alpha<\lambda_{\mathrm{p}}<\lambda_{\mathrm{e}}$$
C
$$\lambda_{\mathrm{e}}>\lambda_\alpha>\lambda_{\mathrm{p}}$$
D
$$\lambda_{\mathrm{p}}<\lambda_{\mathrm{e}}<\lambda_\alpha$$
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