Question

The diagram shows two point charges. The point X is midway between the charges. Calculate the electric field strength at point X due to: (i) 20μ C charge; and (ii) the 40 μ C charge. Also calculate the resultant field strength at point X.

Answer 1

use the formula for electric field-
E = k q /r^2;

Answer 2

Ok i have done the first two questions what about the resultant field strength?

Answer 3

Superposition.

Answer 4

The Superposition Principle states that net electric field produced at any point by a system of charges is equal to the vector sum of all individual fields, produced by each charge at this point. Can you elaborate?

Answer 5

to do question 3, calculate the electric field at X due to the two charges individually, and then look for the directions of the electric field. in this case, both are repulsive so the magnitude of the greater electric field - magnitude of the smaller electric field should be calculated

Answer 6

The mutual electric force between two charges is given
by Coulomb’s law. How to calculate the force on a
charge where there are not one but several charges
around? Consider a system of n stationary charges
q1, q2, q3, ..., qn in vacuum. What is the force on q1 due
to q2, q3, ..., qn? Coulomb’s law is not enough to answer
this question. Recall that forces of mechanical origin
add according to the parallelogram law of addition. Is
the same true for forces of electrostatic origin?
Experimentally it is verified that force on any
charge due to a number of other charges is the vector
sum of all the forces on that charge due to the other
charges, taken one at a time. The individual forces
are unaffected due to the presence of other charges.
This is termed as the principle of superposition

Answer 7

i copy pasted the above one so that i didnt have to type a lot..

Answer 8

Ok so you are saying calculate the magnitude of the smaller electric field can you give me some help please?

Answer 9

okay il write the steps -
calculate electric field due to 20 micro coulomb charge;
do the same for 40 micro coulomb charge.
find which one has a greater electric field strength by comparing the magnitudes. subtract the smaller electric field strength from greater electric field strength to get resultant strength of electric field. i.e Greater strength - smaller strength.

Answer 10

and take distance to be 40 cm and not 80 cm

Answer 11

Electric field strength for 20 micro coulomb charge =1.12*10^6.
Electric field strength for 40 micro coulomb charge = 2.25*10*6

Answer 12

no it is only 1.12 and 2.25 respectively..it is micro coulombs so make sure you included 10^-6 too..

Answer 13

Yes i have done this. so do i subtract 2.25-1.12? And that is the answer

Answer 14

yeah ...

Answer 15

and is that the right answer?

Answer 16

The answer is 1130000 V m ^-1?

Answer 17

im getting 1.13

Answer 18

Is that 1.13 ^ ?

Answer 19

i think you multipled by 10000because you assumed we have to convert it from cm^2 to m^2. noo need for that, we already converted it so answer should be 1.13

Answer 20

Ok thanks

Answer 21

welcome