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
The initial temperature of the bar is 25. To get to the t temperature you need to add (t-25) degrees Celsius.
for 1 degree................... 7 Joules
y given degree........ p Joules
p=7y
In our case y=(t-25) .
h(t) = 7(t-25) which is the final answer.
Answer:
Option B
Explanation:
Gravitational force is a force that attracts two bodies (with a mass) towards each other. If an object has a higher mass, the gravitational pull will be greater.
According to Newton’s inverse square law:
<em>"The gravitational force is inversely proportional to the square of the distance between two bodies."</em>
About this question, the greater the distance between two gravitating bodies, the weaker is the gravitational force between them.