1
JEE Main 2021 (Online) 18th March Evening Shift
+4
-1
The speed of electrons in a scanning electron microscope is 1 $$\times$$ 107 ms-1. If the protons having the same speed are used instead of electrons, then the resolving power of scanning proton microscope will be changed by a factor of :
A
$${1 \over {1837}}$$
B
1837
C
$${\sqrt {1837} }$$
D
$${1 \over {\sqrt {1837} }}$$
2
JEE Main 2021 (Online) 18th March Evening Shift
+4
-1
The decay of a proton to neutron is :
A
always possible as it is associated only with $$\beta$$+ decay
B
possible only inside the nucleus
C
not possible as proton mass is less than the neutron mass
D
not possible but neutron to proton conversation is possible
3
JEE Main 2021 (Online) 18th March Evening Shift
+4
-1
A proton and an $$\alpha$$-particle, having kinetic energies Kp and K$$\alpha$$ respectively, enter into a magnetic field at right angles.

The ratio of the radii of trajectory of proton to that of $$\alpha$$-particle is 2 : 1. The ratio of Kp : K$$\alpha$$ is :
A
8 : 1
B
4 : 1
C
1 : 8
D
1 : 4
4
JEE Main 2021 (Online) 18th March Morning Shift
+4
-1
Imagine that the electron in a hydrogen atom is replaced by a muon ($$\mu$$). The mass of muon particle is 207 times that of an electron and charge is equal to the charge of an electron. The ionization potential of this hydrogen atom will be :
A
13.6 eV
B
2815.2 eV
C
331.2 eV
D
27.2 eV
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