Sunday, September 11, 2022

9702_s19_qp_41 Question 5

 

Answer:

  • Electric field strength is the force per unit positive charge.


Answer:

  • Electric field is a vector quantity and that at any distance x, there are two fields - one due to A and one due to B.

  • These 2 fields are combined to determine the electric field strength E at point P.

  • Based on the graph, 

    • E is zero at x = 10 cm.

    • E is positive at x < 10 cm.

    • E is negative at x > 10 cm.

    • These are only possible if charges A and B have the same sign.


Answer:

  • If there is only one charge creating the field, then E and x follow the inverse-square law.

  • In the situation in this question, the field E is due to a combination of two fields.


Answer:

  • Electric field strength E is given by

E = kQ / x2 .

  • Let EA and EB be the field due to charge A and charge B, respectively.

  • We know from the graph that at x = 10 cm, EA and EB.

EA = EB

kQA / x2 = kQB / (15 - x)2

QA / 102 = QB / 52

QA / QB = 4.0



No comments:

Post a Comment