The cold rolled grain oriented steel has ______ permeability in the direction of the grain orientation.

The correct answer is: B. maximum

Cold rolled grain oriented steel has maximum permeability in the direction of the grain orientation. This is because the grains in cold rolled grain oriented steel are aligned in the direction of rolling, which makes it easier for magnetic fields to pass through the material.

The other options are incorrect because:

• Option A is incorrect because cold rolled grain oriented steel has maximum permeability, not minimum permeability.
• Option C is incorrect because cold rolled grain oriented steel does have permeability, not nil permeability.
• Option D is incorrect because cold rolled grain oriented steel does have permeability in the direction of the grain orientation, not none of the above.