15. Find the electric field intensity at 10cm away from a point charge of 100 esu. a) 1 dyne/esu b) 10 dyne/esu c) 100 dyne/esu d) 9*109 dyne/esu
Answer: a Explanation: We know that electric field intensity at r distance from a point charge q is defined as qr2 in the CGS system. Here q=100 esu, r=10cm. Substituting the value we get E=1dyne/esu. We must remember that factor 14πε is considered only in the SI system and its value is 9*109, but in the CGS system, we simply take the value of this constant as unity.
