A partially polarized light (partially polarized after suitable refraction through a glass slab) is analysed through a rotating polaroid. Hence,

It seems like you didn't finish your question. However, I can start explaining based on what you've provided.

When a partially polarized light passes through a rotating polaroid (also known as a polarizer), the intensity of the transmitted light will vary depending on the angle of the polaroid. This is due to the fact that a polaroid only allows light waves vibrating in a specific direction to pass through.

Here are the steps:

1. The partially polarized light, which has light waves vibrating in more than one plane, is directed towards the polaroid.

2. As the polaroid is rotated, the direction that the polaroid allows light to vibrate in changes.

3. The intensity of the transmitted light is at its maximum when the direction of the polaroid matches the direction of the vibration of the polarized component of the light.

4. The intensity of the transmitted light is at its minimum when the direction of the polaroid is perpendicular to the direction of the vibration of the polarized component of the light.

5. Therefore, as the polaroid is rotated, the intensity of the transmitted light will vary, going from a maximum (when the polaroid's direction matches the light's direction of vibration) to a minimum (when the polaroid's direction is perpendicular to the light's direction of vibration).

Please provide more details if you need further explanation or if your question involves more specific circumstances.