Animals devoid of respiratory,excretory,and circulatory organs are:

Match the items given in the Column-$I$ with those in Column-$II$ and select the correct option given below:

Column-$I$	Column-$II$
$(a)$ Proliferative Phase	$(i)$ Breakdown of endometrial lining
$(b)$ Secretory Phase	$(ii)$ Follicular phase
$(c)$ Menstruation	$(iii)$ Luteal Phase

$A$ graph of magnetic flux $\phi$ versus current $(I)$ is shown for four inductors $A, B, C, D$. The inductor with the smallest value of self-inductance is:

If the peak value of the magnetic field of an electromagnetic wave is $30 \times 10^{-9} \ T$,then the peak value of the electric field is (in $Vm^{-1}$)

$P, Q, R$ and $S$ are four points with the position vectors $3i - 4j + 5k, 2i - j + 4k, -4i + 5j + k$ and $-3i + 4j + 3k$,respectively. Then,the line $PQ$ meets the line $RS$ at the point

The angle between the lines whose direction cosines satisfy the equations $l+m+n=0$ and $l^2+m^2-n^2=0$ is