1
JEE Main 2021 (Online) 24th February Morning Slot
+4
-1
Given below are two statements :

Statement I : Two photons having equal linear momenta have equal wavelengths.

Statement II : If the wavelength of photon is decreased, then the momentum and energy of a photon will also decrease.

In the light of the above statements, choose the correct answer from the options given below.
A
Statement I is false but Statement II is true
B
Both Statement I and Statement II are false
C
Both Statement I and Statement II are true
D
Statement I is true but Statement II is false
2
JEE Main 2020 (Online) 6th September Evening Slot
+4
-1
Assuming the nitrogen molecule is moving with r.m.s. velocity at 400 K, the de-Broglie wavelength of nitrogen molecule is close to :
(Given : nitrogen molecule weight : 4.64 $$\times$$ 10–26 kg,
Boltzman constant: 1.38 $$\times$$ 10–23 J/K,
Planck constant : 6.63 $$\times$$ 10–34 J.s)
A
0.44 $$\mathop A\limits^o$$
B
0.34 $$\mathop A\limits^o$$
C
0.20 $$\mathop A\limits^o$$
D
0.24 $$\mathop A\limits^o$$
3
JEE Main 2020 (Online) 6th September Morning Slot
+4
-1
An electron, a doubly ionized helium ion (He++) and a proton are having the same kinetic energy. The relation between their respective de-Broglie wavelengths $$\lambda$$e, $$\lambda$$He++ and $$\lambda$$p is :
A
$$\lambda$$e > $$\lambda$$He++ > $$\lambda$$p
B
$$\lambda$$e < $$\lambda$$p < $$\lambda$$He++
C
$$\lambda$$e > $$\lambda$$p > $$\lambda$$He++
D
$$\lambda$$e < $$\lambda$$He++ = $$\lambda$$p
4
JEE Main 2020 (Online) 6th September Morning Slot
+4
-1
You are given that Mass of $${}_3^7Li$$ = 7.0160u,
Mass of $${}_2^4He$$ = 4.0026u
and Mass of $${}_1^1H$$ = 1.0079u.
When 20 g of $${}_3^7Li$$ is converted into $${}_2^4He$$ by proton capture, the energy liberated, (in kWh), is :
[Mass of nucleon = 1 GeV/c2]
A
6.82 $$\times$$ 105
B
4.5 $$\times$$ 105
C
8 $$\times$$ 106
D
1.33 $$\times$$ 106
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