Answer:
i think the answer is B but im not sure
Answer:
The distance from the radio station is 0.28 light years away.
Solution:
As per the question:
Distance, d = 4 ly
Frequency of the radio station, f = 854 kHz = 
Power, P = 50 kW = 

Now,
From the relation:
P = nhf
where
n = no. of photons/second
h = Planck's constant
f = frequency
Now,

Area of the sphere, A = 
Now,
Suppose the distance from the radio station be 'r' from where the intensity of the photon is 



Now,
We know that:
1 ly = 
Thus

Usually the unit of measurement of velocity is meters per second or m/s
Answer:
Magnetic field, B = 0.042 T
Explanation:
It is given that,
Speed of charged particle, 
Angle between velocity and the magnetic field, 
Charge, 
Magnetic force, F = 0.002 N
The magnetic force is given by :

B is the magnetic field


B = 0.042 T
So, the strength of the magnetic field is 0.042 Tesla. Hence, this is the required solution.