The part of the castor seed from which oil is obtained is called the .....

Match List-$I$ with List-$II$ for the composition of substances and select the correct answer using the code given below the lists.

List-$I$ (Substances)	List-$II$ (Composition)
$A$. Plaster of Paris	$i$. $CaSO_4 \cdot 1/2H_2O$
$B$. Epsomite	$ii$. $MgSO_4 \cdot 7H_2O$
$C$. Kieserite	$iii$. $MgSO_4 \cdot H_2O$
$D$. Gypsum	$iv$. $CaSO_4 \cdot 2H_2O$
	$v$. $CaSO_4$

$K_2Cr_2O_7$ is preferred to $Na_2Cr_2O_7$ for use in volumetric analysis as a primary standard because:

Two slabs $A$ and $B$ of equal surface area are placed one over the other such that their surfaces are completely in contact. The thickness of slab $A$ is twice that of $B$. The coefficient of thermal conductivity of slab $A$ is twice that of $B$. The first surface of slab $A$ is maintained at $100^{\circ} C$,while the second surface of slab $B$ is maintained at $25^{\circ} C$. The temperature at the contact of their surfaces is (in $^{\circ} C$)

If the circle $x^2+y^2+6x-2y+k=0$ bisects the circumference of the circle $x^2+y^2+2x-6y-15=0$,then $k=$

Which of the following characters are related with Poaceae family?
$(a)$ Basal placentation
$(b)$ Feathery stigma
$(c)$ Cypsela fruit
$(d)$ Pentamerous flower