The correct order of reactivity of $PhMgBr$ with: $(I)$ $Ph-CO-Ph$,$(II)$ $CH_3-CHO$,$(III)$ $CH_3-CO-CH_3$ is:

Temperature of cold junction in a thermocouple is $10^{\circ} C$ and neutral temperature is $270^{\circ} C$,then the temperature of inversion is (in $^{\circ} C$)

Which logic gate is represented by the following combination of logic gates?

The number of molecules in $16 \ g$ of methane is

$A$ metallic frame moves with constant velocity $v$ near an infinitely long current-carrying wire. At any instant,the induced electromotive forces (emf) in sides $AD$ and $BC$ are $5\,V$ and $2\,V$ respectively. If the resistance of the frame is $6\,\Omega$,find the magnitude and direction of the induced current in it.

If $u=e^{x^2-y^2}$,then