Deuteron and $\alpha -$ particle are put $1 \mathrm{A}°$ apart in Air. Magnitude of intensity of electric field due to deuteron at $\alpha -$particle is (N/ C)

Given data: $\alpha \text{ - particle and deuteron are separated by }1°\mathrm{A}\text{ in air. }$

Concept used: electric field and electric field lines  

Detailed solution:

The Electric field of the given system can be expressed as:

$E=9\times {10}^9\frac{q}{r^2}$

$=9\times {10}^9\frac{1.6\times {10}^{-19}}{{\left(1\times {10}^{-10}\right)}^2}=1.44\times {10}^{11} \mathrm{N}/\mathrm{C}$