# Physics equations/18-Electric charge and field/Q:findE

## Practice quiz

1 What is the magnitude of the electric field at the origin if a 1.8 nC charge is placed at x = 7.9 m, and a 2.1 nC charge is placed at y = 7 m?

 a) 2.61 x 10-1N/C b) 3.02 x 10-1N/C c) 3.48 x 10-1N/C d) 4.02 x 10-1N/C e) 4.64 x 10-1N/C

2 What angle does the electric field at the origin make with the x-axis if a 1.1 nC charge is placed at x = -6.5 m, and a 1.4 nC charge is placed at y = -8.3 m?

 a) 3.8 x 101degrees b) 4.39 x 101degrees c) 5.06 x 101degrees d) 5.85 x 101degrees e) 6.75 x 101degrees

3 A dipole at the origin consists of charge Q placed at x = 0.5a, and charge of -Q placed at x = -0.5a. The absolute value of the x component of the electric field at (x,y) =( 6a, 4a) is βkQ/a2, where β equals

 a) 1.33 x 10-3 b) 1.61 x 10-3 c) 1.95 x 10-3 d) 2.37 x 10-3 e) 2.87 x 10-3

4 A dipole at the origin consists of charge Q placed at x = 0.5a, and charge of -Q placed at x = -0.5a. The absolute value of the y component of the electric field at (x,y) =( 1.1a, 1.2a) is βkQ/a2, where β equals

 a) 2.36 x 10-1 b) 2.86 x 10-1 c) 3.47 x 10-1 d) 4.2 x 10-1 e) 5.09 x 10-1