Ans: The thin strands are called as yarns which are made from fibre. Spinning is the process of making yarn. The process where the cotton wool are drawn out and being twisted. This process brings all the fibre together to form a yarn.
Answer:

Explanation:
Given that,
The speed of an electromagnetic wave traveling in a transparent nonmagnetic substance is given by :

Where
k is the dielectric constant of the substance.
v is the speed of light in water


So, the speed of light in water is 
Simply, apply the formula

and insert the values of m = mass, v = velocity and E = Energy.
The result will be

, m = 1 kg
Answer:
a) their potential energy increases.
Explanation:
Ohm's Law is
R= V/I
Where R= Resistance
V= potential difference or potential energy
I= current or conduction electron flow rate
Clearly R and V are directly proportional i-e Potential energy increases with resistance.