The electric field and force experienced by a test charge placed at origin is 6 x 105 N/C and 18 x 10-4 N. The value of test charge is:
6 nC
9 nC
3 nC
12 nC
A test charge of 3nC is placed at origin and experiences a force of 9 x 10-4 N. The electric field at origin is: