It's actually Friction.
I just did the test and got it right.
Answer:
The current in wire resistance 2Ω
a). 8696 A
b). fraction power 15.1% a 115kV
Explanation:
Resistance
Ω/Km*40km
R=2Ω
P=1000 MW
a).

Using law ohm
b).


%
Rainbows are caused by the dispersion of light, which itself consists of a combination of refraction and reflection of light around little droplets of water.
Choice C
Answer:
Part a)

Part b)
if both sides are rough then it will reach the same height on the other side because the energy is being conserved.
Part c)
Since marble will go to same height when it is rough while when it is smooth then it will go to the height

so on smooth it will go to lower height
Explanation:
As we know by energy conservation the total energy at the bottom of the bowl is given as

here we know that on the left side the ball is rolling due to which it is having rotational and transnational both kinetic energy
now on the right side of the bowl there is no friction
so its rotational kinetic energy will not change and remains the same
so it will have

now we know that


so we have




so the height on the smooth side is given as

Part b)
if both sides are rough then it will reach the same height on the other side because the energy is being conserved.
Part c)
Since marble will go to same height when it is rough while when it is smooth then it will go to the height

so on smooth it will go to lower height