Question

A charged object is immersed in a 17 N/C E-field. Then the total charge on the object increases by a factor of 22 over 10 s. During this time, the electrostatic force on the object remains constant. Determine the magnitude of the E-field after the total charge has changed.

Answer 1

Answer:

Eu = 0.65 N/C (Approx)

Explanation:

Given:

Time taken = 10 sec

E-field (Initial)(Ei) = 17 N/C

Find:

E-field (Final)

Assume;

Initial charge = Qi

Initial immersed force (Fi) = QiE

Fi = Qi(17)

After 10 sec

Fu = (26)(Qi)(Eu)

So

Fi = Fu

So,

Qi(17) = (26)(Qi)(Eu)

Eu = 17 / 26

Eu = 0.65 N/C (Approx)

Answer 2

Given :

Initial electric field , $E_i=17\ N/C$ .

The total charge on the object increases by a factor of 22 .

To Find :

The magnitude of the E-field after the total charge has changed .

Solution :

Let , initial charge is q .

Therefore , final charge is 22q .

Electrostatic force F is given by :

$F=qE$

It is also given that the force remains constant .

Therefore ,

$F_i=F_f\\\\qE_i=22qE_f\\\\E_f=\dfrac{E_i}{22}\\\\E_f=\dfrac{17}{22}\ N/C\\\\E_f=0.78\ N/C$

Hence , this is the required solution .