Fill in the blank spaces with appropriate answers:
A double convex air bubble in water behaves as a ______ lens.

An air bubble in water behaves as ____.

Fill in the blanks spaces with appropriate answers. Unlike currents……….

Fill in the blanks spaces with appropriate answers. ………..currents attract.

Fill in the blank spaces with appropriate answer: An isolated magnetic pole ____ exists.

Fill in the blank spaces with appropriate answers : MKS unit of conductivity is………… .

Fill in the blank spaces with appropriate answers: A double convex lens of focal length 'f' is cut at 90^@ to its principal axis into two identical component lenses. The focal length of each component lens is _________.

Fill in the blank spaces with appropriate answers: Nuclear force is _______ range force.

Fill in the blanks spaces with appropriate answers. Amperer is defined from……….