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
1.Light-collecting area
2.Angular resolution
1. They have evolved their leaves into spikes for minimum water loss through transpiration.
2. They have a waxy layer for minimum water loss.
3. They have thick walls for minimum water loss.
4. They can take water from atmosphere.
5. They change the photo energy from Sun into an intermediate stage and store it, so that they can make food even in night.
Answer:

Explanation:
Given that,
The distance between two spheres, r = 25 cm = 0.25 m
The capacitance, C = 26 pF = 26×10⁻¹² F
Charge, Q = 12 nC = 12 × 10⁻⁹ C
We need to find the work done in moving the charge. We know that, work done is given by :

Put all the values,

So, the work done is
.