1
JEE Main 2021 (Online) 27th August Evening Shift
+4
-1
A monochromatic neon lamp with wavelength of 670.5 nm illuminates a photo-sensitive material which has a stopping voltage of 0.48 V. What will be the stopping voltage if the source light is changed with another source of wavelength of 474.6 nm?
A
0.96 V
B
1.25 V
C
0.24 V
D
1.5 V
2
JEE Main 2021 (Online) 27th August Morning Shift
+4
-1
In a photoelectric experiment, increasing the intensity of incident light :
A
increases the number of photons incident and also increases the K.E. of the ejected electrons
B
increases the frequency of photons incident and increases the K.E. of the ejected electrons
C
increases the frequency of photons incident and the K.E. of the ejected electrons remains unchanged
D
increases the number of photons incident and the K.E. of the ejected electrons remains unchanged
3
JEE Main 2021 (Online) 26th August Evening Shift
+4
-1
The de-Broglie wavelength of a particle having kinetic energy E is $$\lambda$$. How much extra energy must be given to this particle so that the de-Broglie wavelength reduces to 75% of the initial value?
A
$${1 \over 9}$$E
B
$${7 \over 9}$$E
C
E
D
$${16 \over 9}$$E
4
JEE Main 2021 (Online) 26th August Morning Shift
+4
-1
In a photoelectric experiment ultraviolet light of wavelength 280 nm is used with lithium cathode having work function $$\phi$$ = 2.5 eV. If the wavelength of incident light is switched to 400 nm, find out the change in the stopping potential. (h = 6.63 $$\times$$ 10$$-$$34 Js, c = 3 $$\times$$ 108 ms$$-$$1)
A
1.3 V
B
1.1 V
C
1.9 V
D
0.6 V
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