One of the efficient concepts that can help us find the number of turns of the cable is through the concept of induced voltage or electromotive force given by Faraday's law. The electromotive force or emf can be described as,

Where,
N = Number of loops
B = Magnetic Field
A = Cross-sectional Area
= Angular velocity
Re-arrange to find N,

Our values are given as,




Replacing at our equation we have:



Therefore the number of loops of wire should be wound on the square armature is 32 loops
According to snells law
<span>n1 sin theta1 = n2 sin theta2
</span>n1 = 1.333 (water)
<span>n2 = 2.42 (diamond)</span>
it is given that theta =30 degrees so
by putting the values we have
<span>1.333 sin theta = 2.42 sin 30 </span>
<span>sin theta = (2.42/1.333) *0.5 =65.2 degree
</span>so our conclusion is
<span>the ray's angle of incidence θ1 on the diamond</span> = 65.2 degree.
hope this helps
Answer:
The combined magnetic force of the magnetized wire coil and iron bar makes an electromagnet very strong. In fact, electromagnets are the strongest magnets made. An electromagnet is stronger if there are more turns in the coil of wire or there is more current flowing through it.