Question

The electric field 0.4m away from a very long uniform line of charge is 840n/c.how much charge is contained in 2cm section of the line

Answer 1

In this question we use the formulae for getting the linear charge density given the charge and the length.

FORMULAE :

Linear charge density = Q / L where the Q represents the quantity of charge and L the total length.

In this question we have the total length as 0.4m and the linear density as 840n/C.

We need to work out the charge from the formula above.

CALCULATIONS :

840 =Q/0.4

Q = 840 × 0.4 =336Coulombs.

This charge is contained in 0.4m which is equivalent to 40cm.

We want to find how much charge is contained in 2cm.

We get the total number of pieces in 40cm.

40/2=20 pieces.

Charge in one 2cm piece =total charge in 40cm ÷ 20 pieces.

336/20= 16.8 Coulombs.