Select the correct pair from the following.

If $\log_{7} 2 = m$,then $\log_{49} 28$ is equal to

Which of the following is a wheat fruit?

Which of the following is the correct electronic configuration of $Cr$ $(Z=24)$?

The correct match of the group reagents in List$-I$ for precipitating the metal ion given in List$-II$ from solutions, is

List$-I$	List$-II$
$(P)$ Passing $H _2 S$ in the presence of $NH _4 OH$	$(1) \ Cu ^{2+}$
$(Q) \ \left( NH _4\right)_2 CO _3$ in the presence of $NH _4 OH$	$(2) \ Al ^{3+}$
$(R) \ NH _4 OH$ in the presence of $NH _4 Cl$	$(3) \ Mn ^{2+}$
$(S)$ Passing $H _2 S$ in the presence of dilute $\text{HCl}$	$(4) \ Ba ^{2+}$
	$(5) \ Mg ^{2+}$

Consider the situation shown in the figure. Water $(\mu = 4/3)$ is filled in a beaker up to a height of $10 \, cm$. $A$ plane mirror is fixed at a height of $5 \, cm$ from the surface of the water. The distance of the image from the mirror after reflection from it of an object $O$ at the bottom of the beaker is ..... $cm$.