1
WB JEE 2020
+1
-0.25
If R is the Rydberg constant in cm-1, then hydrogen atom does not emit any radiation of wavelength in the range of
A
$${1 \over R}$$ to $${4 \over {3R}}$$ cm
B
$${7 \over 5R}$$ to $${19 \over {5R}}$$ cm
C
$${4 \over R}$$ to $${36 \over {5R}}$$ cm
D
$${9 \over R}$$ to $${144 \over {7R}}$$ cm
2
WB JEE 2019
+1
-0.25
A proton and an electron initially at rest are accelerated by the same potential difference. Assuming that a proton is 2000 times heavier than an electron, what will be the relation between the de Broglie wavelength of the proton ($$\lambda$$p) and that of electron ($$\lambda$$e)?
A
$$\lambda = 2000{\lambda _e}$$
B
$${\lambda _p} = {{{\lambda _e}} \over {2000}}$$
C
$${\lambda _p} = 20\sqrt 5 {\lambda _e}$$
D
$${\lambda _p} = {{{\lambda _e}} \over {20\sqrt 5 }}$$
3
WB JEE 2019
+1
-0.25
To which of the following the angular velocity of the electron in the n-th Bohr orbit is proportional?
A
$${n^2}$$
B
$${1 \over {{n^2}}}$$
C
$${1 \over {{n^{3/2}}}}$$
D
$${1 \over {{n^3}}}$$
4
WB JEE 2018
+1
-0.25
How the linear velocity v of an electron in the Bohr orbit is related to its quantum number n?
A
$$v \propto {1 \over n}$$
B
$$v \propto {1 \over {{n^2}}}$$
C
$$v \propto {1 \over {\sqrt n }}$$
D
$$v \propto n$$
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