1
JEE Main 2022 (Online) 25th July Evening Shift
MCQ (Single Correct Answer)
+4
-1
Change Language

The ratio of wavelengths of proton and deuteron accelerated by potential Vp and Vd is 1 : $$\sqrt2$$. Then the ratio of Vp to Vd will be :

A
1 : 1
B
$$\sqrt2$$ : 1
C
2 : 1
D
4 : 1
2
JEE Main 2022 (Online) 25th July Morning Shift
MCQ (Single Correct Answer)
+4
-1
Change Language

A metal exposed to light of wavelength $$800 \mathrm{~nm}$$ and and emits photoelectrons with a certain kinetic energy. The maximum kinetic energy of photo-electron doubles when light of wavelength $$500 \mathrm{~nm}$$ is used. The workfunction of the metal is : (Take hc $$=1230 \,\mathrm{eV}-\mathrm{nm}$$ ).

A
1.537 eV
B
2.46 eV
C
0.615 eV
D
1.23 eV
3
JEE Main 2022 (Online) 30th June Morning Shift
MCQ (Single Correct Answer)
+4
-1
Change Language

A source of monochromatic light liberates 9 $$\times$$ 1020 photon per second with wavelength 600 nm when operated at 400 W. The number of photons emitted per second with wavelength of 800 nm by the source of monochromatic light operating at same power will be :

A
12 $$\times$$ 1020
B
6 $$\times$$ 1020
C
9 $$\times$$ 1020
D
24 $$\times$$ 1020
4
JEE Main 2022 (Online) 29th June Evening Shift
MCQ (Single Correct Answer)
+4
-1
Change Language

The electric field at a point associated with a light wave is given by

E = 200 [sin (6 $$\times$$ 1015)t + sin (9 $$\times$$ 1015)t] Vm$$-$$1

Given : h = 4.14 $$\times$$ 10$$-$$15 eVs

If this light falls on a metal surface having a work function of 2.50 eV, the maximum kinetic energy of the photoelectrons will be

A
1.90 eV
B
3.27 eV
C
3.60 eV
D
3.42 eV
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