Answer:
(A) Acceleration will be 
(b) Time taken will be 
(c) Force will be
Explanation:
We have given that electron starts from rest so initial velocity u = 0 m/sec
Final velocity 
Mass of electron 
Distance traveled by electron 
From third equation of motion we know that 
(a) So 

(b) From first equation of motion we know that v = u+at
So 

(c) From newton's law we know that force

Option ( c ) is correct.
Using the formula for power

P= power
i= current= 0.4 A
R= resistance= 30 ohm
so power= (0.4)² (30)
Power=4.8 W
Light is faster. Humans can travel faster than sound, however not light- nothing seems to go faster than 3×10∧8 meters per second.
Answer:
1) The medium b has higher optical density.
2) If the optical densities of both A and B are same.
Explanation:
- The refractive index of a material determines the number of times the velocity of light in that material is slower than the velocity of light in a vacuum.
- The higher refractive index means slower propagation of the light in that medium.
- The refractive index of the medium determines the optical density of the medium.
- If the material has a higher refractive index, then its optical density is high.
- If the material has a low refractive index, then its optical density is low.
- The light bends towards the normal while refracting through the medium from a lower optical density medium to the higher optical density medium.
- If both the mediums has the same optical density, the direction of propagation doesn't change.