Wires $P$ and $Q$ have the same resistance at ordinary (room) temperature. When heated,the resistance of $P$ increases and that of $Q$ decreases. We conclude that

Match Column-$I$ with Column-$II$ and select the correct option.

Column-$I$	Column-$II$
$A$. Fishes	$(i)$. Three-chambered heart
$B$. Amphibians	$(ii)$. Incomplete double circulation
$C$. Birds	$(iii)$. Four-chambered heart
	$(iv)$. Single circulation
	$(v)$. Two-chambered heart
	$(vi)$. Double circulation

If $x = \tan 15^{\circ}$,$y = \operatorname{cosec} 75^{\circ}$ and $z = 4 \sin 18^{\circ}$,then :

Which of the following statements are true regarding Bohr's model of the hydrogen atom?
$(I)$ Orbiting speed of the electron decreases as it shifts to discrete orbits away from the nucleus.
$(II)$ Radii of allowed orbits of the electron are proportional to the principal quantum number.
$(III)$ Frequency with which electrons orbit around the nucleus in discrete orbits is inversely proportional to the cube of the principal quantum number.
$(IV)$ Binding force with which the electron is bound to the nucleus increases as it shifts to outer orbits.
Select the correct answer using the codes given below.

If $Alpha$,$Beta$,and $\Gamma$ rays carry the same momentum,which has the longest wavelength?

Match the following:

Column-$I$	Column-$II$
$1$. Pituitary gland	$p$. Trachea
$2$. Thyroid gland	$q$. Bony cavity (Sella tursica)
$3$. Thymus	$r$. Anterior part of kidney
$4$. Adrenal glands	$s$. Dorsal side of the heart and aorta