Answer:
The ratio of the resistances of second coil to the first coil is the ratio of square of radius of the first coil to the square of radius of second coil.
And
The ratio of the resistances of fourth coil to the third coil is the ratio of square of radius of the third coil to the square of radius of fourth coil.
Explanation:
The resistance of the coil is directly proportional to the length of the coil and inversely proportional to the area of coil and hence inversely proportional to the square of radius of the coil.
So, the ratio of the resistances of second coil to the first coil is the ratio of square of radius of the first coil to the square of radius of second coil.
And
The ratio of the resistances of fourth coil to the third coil is the ratio of square of radius of the third coil to the square of radius of fourth coil.
(a) Zero
The maximum efficiency (Carnot efficiency) of a heat engine is given by

where
is the low-temperature reservoir
is the high-temperature reservoir
For the heat engine in the problem, we have:


Therefore, the maximum efficiency is

(b) Zero
The efficiency of a heat engine can also be rewritten as

where
W is the work performed by the engine
is the heat absorbed from the high-temperature reservoir
In this problem, we know

Therefore, since the term
cannot be equal to infinity, the numerator of the fraction must be zero as well, which means
W = 0
So the engine cannot perform any work.
A. gravity is your answer hope this helps
Answer: burning of the incense and air drift in the room
Explanation: the smoke will automatically rise to the top of the room and then with air drift if would help spread further around the room and spread the smell