Effect of short pitched coil on generated EMF:

A short pitched coil refers to a coil in which the turns are closer to each other than in a normal coil. This means that the distance between adjacent turns is reduced.

When a coil is rotated in a magnetic field, an electromotive force (EMF) is induced in the coil due to the relative motion between the coil and the magnetic field. This EMF can be calculated using Faraday's law of electromagnetic induction, which states that the magnitude of the induced EMF is directly proportional to the rate of change of magnetic flux passing through the coil.

Now let's consider the effect of short pitching on the generated EMF:

1. Increased flux linkage:
- The flux linkage is a measure of the total magnetic flux passing through the coil. In a short pitched coil, the turns are closer to each other, which means that the magnetic field lines passing through one turn will also pass through the neighboring turns.
- This increased flux linkage leads to a higher rate of change of magnetic flux when the coil rotates, resulting in a larger induced EMF.

2. Increased self-inductance:
- Self-inductance is a property of a coil that opposes any change in the current flowing through it. It is directly proportional to the number of turns in the coil and the square of the radius of the coil.
- In a short pitched coil, the number of turns is effectively increased due to the closer spacing between them. This leads to an increase in self-inductance.
- An increase in self-inductance means that the coil will generate a higher back EMF, which opposes the applied voltage and reduces the net generated EMF.

3. Increased magnetic coupling:
- Magnetic coupling refers to the extent to which the magnetic field lines produced by one coil pass through the neighboring coils.
- In a short pitched coil, the magnetic coupling between adjacent turns is increased due to the closer proximity.
- This increased magnetic coupling leads to a higher mutual inductance between the turns, which can affect the generated EMF.
- The exact effect of increased magnetic coupling on the generated EMF depends on the specific configuration and design of the coil.

Based on the above considerations, it can be concluded that a short pitched coil will tend to decrease the generated EMF. This is because the increase in flux linkage and self-inductance is offset by the higher back EMF and potential effects of increased magnetic coupling. Therefore, the correct answer to the question is option 'B' - decreasing.