In the interval $(-3, 3)$, the function $f(x) = \frac{x}{3} + \frac{3}{x}, x \neq 0$ is :

$NH_3 + O_2 \xrightarrow[\Delta]{Pt} A + H_2O;$
$A + O_2 \to B$
$B + O_2 + H_2O \to C$
$A, B$ and $C$ are:

$A$ current of $5 ~A$ is flowing at $220 ~V$ in the primary coil of a transformer. If the voltage produced in the secondary coil is $2200 ~V$ and $50 \%$ of power is lost,then the current in the secondary coil will be: (in $~A$)

$A$ system is provided with $50 \ J$ of heat and the work done on the system is $10 \ J$. What is the change in internal energy of the system in joules?

Two point charges $-10 \mu C$ and $+5 \mu C$ are situated on the $X$-axis at $x=0$ and $x=\sqrt{2} \ m$. The point along the $X$-axis where the electric field becomes zero is:

What does the given experimental set-up depict?
Choose the correct option accordingly.