Which of the following is $NOT$ a characteristic of the phylum $Annelida$?

Which of the following metal chlorides has the highest covalent character?

$A$ wire fixed at the upper end stretches by length $l$ by applying a force $F$. The work done in stretching is

While a collector to emitter voltage is constant in a transistor,the collector current changes by $8.2 ~mA$ when the emitter current changes by $8.3 ~mA$. The value of forward current ratio is

$A$ single slit of width $0.20 \, mm$ is illuminated with light of wavelength $500 \, nm$. The observing screen is placed $80 \, cm$ from the slit. The width of the central bright fringe will be.....$mm$

The Effective Atomic Number $(EAN)$ of $Co(CO)_4$ is $35$,hence it is less stable. It attains stability by: