Q 12-01-022JEE MainMedium
A small ball of mass $2$ g and charge $+5\ \mu$C hangs from a thread in a uniform horizontal electric field. In equilibrium the thread makes $45°$ with the vertical. Find the field strength in N/C. ($g = 10\ \text{m/s}^2$)
Numerical value type. Enter your answer.
Answer: 4000
$\tan 45° = \dfrac{qE}{mg} \Rightarrow E = \dfrac{mg}{q} = \dfrac{2 \times 10^{-3} \times 10}{5 \times 10^{-6}} = 4000$ N/C.
Solution by Sreeraj P, M.Sc Physics