Three charges \[1\mu C,\,\,1\mu C\] and \[2\mu C\] are kept at the vertices \[A,\,\,B\] and \[C\] of an equilateral triangle \[ABC\] of \[10cm\] side, respectively. The resultant force on the charge at \[C\] is
A)\[0.9N\]
B)\[1.8N\]
C)\[2.72N\]
D)\[3.6N\]
Correct Answer:
D
Solution :
The situation is shown in figure. Force on \[C\] due to \[A\] \[{{F}_{AC}}=\frac{1}{4\pi {{\varepsilon }_{0}}}\frac{{{q}_{A}}{{q}_{C}}}{r_{AC}^{2}}\] \[=\frac{9\times {{10}^{9}}\times 1\times 2\times {{10}^{-12}}}{{{(0.1)}^{2}}}=1.8N\] Similarly, \[{{F}_{BC}}=1.8N\] Hence, net force on \[C={{F}_{AC}}+{{F}_{BC}}=3.6N\]