The rest energy of an electron is - Vidyadip

MCQ

The rest energy of an electron is

✓
$510\, KeV$
B
$931\, KeV$
C
$510 \,MeV$
D
$931\, MeV$

✓

Answer

Correct option: A.

$510\, KeV$

a
(a) Rest energy of an electron ${r_n} \propto {n^2}$

Here ${m_e} = 9.1 \times {10^{ - 31}}kg$ and $c =$ velocity of light

$\therefore $Rest energy $ = 9.1 \times {10^{ - 31}} \times {(3 \times {10^8})^2}joule$

$ = \frac{{9.1 \times {{10}^{ - 31}} \times {{(3 \times {{10}^8})}^2}}}{{1.6 \times {{10}^{ - 19}}}}eV = 510\;keV$

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free

Explore more

More "M.C.Q (1 Marks)" from 13. Nuclei→13. Nuclei — all question types→Physics STD 12 Science question papers→CBSE Board STD 12 Science question papers→CBSE Board question paper generator→

Similar questions

At a place, the magnitudes of the horizontal component and total intensity of the magnetic field of the earth are 0.3 and 0.6 Oersted respectively. The value of the angle of dip at this place will be

The ripple factor in a half wave rectifier is

A capacitor consists of two parallel plates, with an area of cross-section of $0.001 m^2$, separated by a distance of 0.0001 m. If the voltage across the plates varies at the rate of $10^8 V / s$, then the value of displacement current through the capacitor is

A very long bar magnet is placed with its north pole coinciding with the centre of a circular loop carrying as electric current i. The magnetic field due to the magnet at a point on the periphery of the wire is B. The radius of the loop is a. The force on the wire is:

In X-ray tube when the accelerating voltage V is halved, the difference between the wavelength of $\mathrm{K}_a$ line and minimum wavelength of continuous X-ray spectrum

The magnetic field around a long straight current carrying wire is:

By a cell a current of $0.9\, A$ flows through $2\, ohm$ resistor and $0.3\,A$ through $7\, ohm$ resistor. The internal resistance of the cell is ............ $\Omega$

The magnetic dipole moment of a current carrying coil does not depend upon:

If a glass rod is rubbed on silk cloth and then brought near the bits of paper it $........$ then.

A transformer with turns ratio $\frac{ N _{1}}{ N _{2}}=\frac{50}{1}$ is connected to a $120$ volt $AC$ supply. If primary and secondary circuit resistances are $1.5\, k \Omega$ and $1\, \Omega$ respectively then find out power out put (in $W$)