Answer:
The direction of the magnetic field around the coil reverses. The force on the cone now pulls it back in. Repeatedly alternating the current direction makes the cone vibrate in and out. The cone vibrations cause pressure variations in the air, which are sound waves.
Explanation:So as it goes back and forth it makes a sound from the vibration.
Answer:
Monopsony
Explanation:
Kinda like a monopoly, except instead of one producer it is one buyer.
Answer:
Concentration factor will be 1.2
So option (C) will be correct answer
Explanation:
We have given outer diameter D = 1.25 in
And inner diameter d = 1 in and fillet ratio r = 0.2 in
So
ratio will be 
And
ratio will be 
Now from the graph in shaft vs torsion the value of concentration factor will be 1.2
So concentration factor will be 1.2
So option (C) will be correct answer.