00:01
In this problem, we have been given that there are two charges.
00:03
Q and q they are kept at the positions indicated, and we need to figure out the total electric field's magnitude at this point b, provided that a is 60 centimeter, b is 80 centimeters, and charge capital q is minus 6 nanoculum, which is minus 6 into 10 raise to minus 9 column, and small q charge, that's 3 into 10 raise to minus 9 column.
00:28
So here we will use the expression of electric field that's kq by r square to get the electric field because of one point charge.
00:36
Since q is negative, we know the direction of electric field.
00:39
It's from positive to the negative.
00:41
So it will be in this direction.
00:43
And electric field because of this small q that will be in this direction along the line joining because it's positive charge and electric field will be away from it.
00:53
Now here we observe.
00:54
Let's take the electric field because of small charges e and electric field because of the big q charge as so e here will be 9 into 10 raise to 9 that's the value of k we multiply with the magnitude of charge that's 6 into 10 raise to minus 9 and we divide it by the square of the distance here we observe that the angle is 90 degree and using pythagoras rule the distance r can be computed by taking the squares of a and b and taking the root of that so we get that as 100 cm, which is 1 meters.
01:30
So when we square one, it's going to be just the same thing.
01:33
So the electric field comes out to be 54 newton's per column.
01:37
Also, let's figure out the angle here because we will require them to get the complete magnitude.
01:43
So angle can be determined by using simple trigonometry, and that angle will be tan inverse of the perpendicular upon the adjacent.
01:51
So when we take the perpendicular and divide it by the adjacent, we're going to get to.
01:56
0 .75 and we take the tan inverse of that to get the angle here as 37 degree approximately.
02:06
So here the magnitude of this electric field we have figured out and let's convert that in terms of vector.
02:12
So it will have two components, one along the negative x direction and along the positive y direction will be one component.
02:20
So e vector will be minus e cos 37 degree along i cap plus e sine 37 degree along positive wide direction.
02:32
So here when we multiply 54 with the value of cost 37, we're going to get minus 43 .2 icap plus here we multiply the magnitude of e with sign 37, and that's 32 .4j cap...