Band spectrum is produced by

The spectrum obtained from a sodium vapour lamp is an example of

An electron passing through a potential difference of $4.9 \ V$ collides with a mercury atom and transfers it to the first excited state. What is the wavelength of a photon corresponding to the transition of the mercury atom to its normal state in $\mathring{A}$?

The spectrum of iodine gas under white light will be:

Line spectrum contains information about

Match the following:

$1$. Burning candle	$i$. Line spectrum
$2$. Sodium vapour	$ii$. Continuous spectrum
$3$. Bunsen flame	$iii$. Band spectrum
$4$. Dark lines in solar spectrum	$iv$. Absorption spectrum