Earthworms can feel the vibrations of the gound by presence of

Earthworm is brown due to presence of

Earthworms is brown due to presence of

The given reaction can occur in the presence of :

The cobra can be distinguished by the presence of

The colour of the body in earthworm is brown due to the presence of

Alkanes can be iodinated in the presence of

Alkanes can be iodinated in the presence of

The diagram in Fig. shows three ways in which a string of length I in an instrument can vibrate. Which vibration is of the longest wavelength ?