Answer:

Solution:
As per the question:
Point charge, q = 
Test charge, 
Work done by the electric force, 
Now,
We know that the electric potential at a point is given by:

where
r = separation distance between the charges.
Also,
The work done by the electric force i moving a test charge from point A to B in an electric field:




Answer:
(a) 
Explanation:
We have given speed of light 
Given time = 1 year =365 days
We know that in 1 minute = 60 sec
1 hour = 60×60 = 3600 sec
In one day = 24 hour = 24×60×60=86400 sec
So in 365 days = 365×86400
We know that distance = speed ×time
We have given that 1 mi = 1609 m
So
So option (a) is correct
In order to answer the question, we need to know what was there before
AND what was there after. Is there a reason why you're concealing that
information ?
While you're at it, you might pass along the answer choices too.
Conservation of momentum: total momentum before = total momentum after
Momentum = mass x velocity
So before the collision:
4kg x 8m/s = 32
1kg x 0m/s = 0
32+0=32
Therefore after the collision
4kg x 4.8m/s = 19.2
1kg x βm/s = β
19.2 + β = 32
Therefore β = 12.8 m/s
Answer:
Radius, r = 0.00523 meters
Explanation:
It is given that,
Magnetic field, 
Current in the toroid, I = 9.6 A
Number of turns, N = 6
We need to find the radius of the toroid. The magnetic field at the center of the toroid is given by :

r = 0.00523 m
or

So, the radius of the toroid is 0.00523 meters. Hence, this is the required solution.