Two 1 Coulomb charges are kept at 1m distance in air medium. Force of attraction or repulsion between them will be ________
A. 9*109 N
B. 1 dyne
C. 1 N
D. 3*103 N
Answer:A
Two 1 Coulomb charges are kept at 1m distance in air medium. Force of attraction or repulsion between them will be ________
A. 9*109 N B. 1 dyne C. 1 N D. 3*103 N
Explanation: According to Coulomb’s Law, F=\(\frac {1}{4\pi \varepsilon_o }*\frac {q_1q_2}{r^2}\). And \(\frac {1}{4\pi \varepsilon_o}\) = 9*109N in the SI system. In this case, q1=q2=1C and r=1m. Now substituting the values we get F=9*109N. Similarly, the electric field at a distance of 1m from a 1C charge is 9*109N/C.