Question

Two charges -20μC and +15 μC are separated by a distance of 15 cm. What is the electric field at point A that is 10cm from the charge -20 μC?

1. Two charges-2011C and +15 μC are separated by a distance of 15 cm. What is the electric field at point A that is 10cm from the charge-20-C? (a) 1.8x10 N/C (b) 3.6x10 N/C (c) 5.4x10 N/C (d 7.2x10 NIC -20 uC +15uC

Answer 1

Electric field at A is algebric sum of individual electric field due to each charge, that is to the left

E = electric field due to (- 20 uC) + electric field due to (15uC)

E = k q1 / r1^2 + k q2 / r2^2

E = 9*10^9 * 20 * 10^-6 / 0.1^2 + 9*10^9* 15*10^-6 / 0.05^2

E = 7.2*10^7 N/C

option (d) is correct

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