Ink is adsorbed on the chalk., in this ink and chalk are respectively

Ink gland are present in

Ink glands are found in

An ink container of cylindrical shape is filled with ink upto 91% Ballpen refills of length 12 cm and inner diameter 2 mm are filled upto 84% . IF the height and radius of the ink container are 14 cm and 6 cm respectively, find the number of refills that can be filled with this ink.

Ink-gland is absent in

Ink-gland is absent in

Ink-gland is absent in

Ink-gland is absent in

Why we put an ink mark on the chalk?

Ink-gland is present in