Answer:

Explanation:
The formula for the force exerted between two charges is

where k is the Coulomb constant.
The charges are identical, so we can write the formula as


Answer:
7. I and III only.
Explanation:
Only portions of the electromagnetic spectrum is visible to the human eye. Electromagnetic radiation in this range of wavelengths is called visible light which have wavelengths from about 390 to 750 nm that is; ultraviolet light and visible light.
Answer:
M = 222 fringes
Explanation:
given
λ = 559 n m = 559 × 10⁻⁹ m
radius = 0.026 mm = 0.026 ×10⁻³ m
length of the glass plate = 22.1 ×10⁻² m
using relation


= 221.79
= 221 (approx.)
hence no of bright fringe
M = m + 1
= 221 +1
M = 222 fringes
Explanation:
because the moon has less mass than earth, the force due to gravity at the lunar surface is only about 1/6 that on earthso,the weight of a body on earth is 6×5N =30N
Answer:
ratio =0.3075 T
Explanation:
The magnetic field B creates a force on a moving charge such that

Now this causes a centripetal acceleration

so
...........(i)
...............(ii)
If accelerating potential V is same and then kinetic energy equals the potential energy difference

put these value in equation (ii)
simplifying we get

for same location r will be same in both case
..............(iii)
..........(iv)
dividing (iv) and (iii) equation we get



so on solving we get
=0.3075 T