A charge \(50 \mu \mathrm{C}\) has an electric field strength of \(360 \mathrm{NC}^{-1}\) at a certain point. The electric strength due to another charge \(120 \mu \mathrm{C} \mathrm{kept}\) at the same distance apart and in the same medium is ____________
A. \(18 \mathrm{NC}^{-1}\) B. \(144 \mathrm{NC}^{-1}\) C. \(854 \mathrm{NC}^{-1}\) D. \(150 \mathrm{NC}^{-1}\)
Correct Answer:
Explanation
Let \(\mathrm{E}=\) Electric field strength \(1 / 4^{\wedge} 2=\) constant \(=9.05 \times 10^{9}\) \(\mathrm{Q}_{1}=50 \mathrm{UC}=50 \times 10^{-6} \mathrm{C}, \mathrm{Q}_{2}=120 \mathrm{UC}=120 \times 10^{-6}\) \(=\mathrm{C}\).ut \(\mathrm{E}_{1}=\frac{1}{4^{\wedge} E o}=\frac{\Phi_{1}}{r^{2}}\) \(\Rightarrow \quad 360=\frac{1}{4^{\wedge} E 0}=\frac{50 \times 10-6}{r^{2}}\)ut \(\mathrm{E}_{2}=\frac{1}{4^{\wedge} \mathrm{EO}^{-0.8}}=\frac{\oplus_{2}}{r^{2}}=\frac{120 \times 10^{-6}}{=8.84 \times 10^{9} \times 10^{9} \times 1.5 \times 10^{-17}}\)
