An inductor and a resistor are connected in series to an $AC$ source of $10 \ V$. If the potential difference across the inductor is $6 \ V$,then the potential difference across the resistor is: (in $V$)

In the given reaction,$A$ is:
$A$ $\xrightarrow{\text{Reduction}} B$ $\xrightarrow{HNO_2} C_2H_5OH$

$A$ metal rod of length $2 \text{ m}$ has cross-sectional areas $2A$ and $A$ as shown in the figure. The ends are maintained at temperatures $100^{\circ}\text{C}$ and $70^{\circ}\text{C}$. The temperature at the middle point $C$ is...... $^{\circ}\text{C}$

If $ax^2+2hxy-2ay^2+3x+15y-9=0$ represents a pair of lines intersecting at $(1,1)$,then $ah=$

At $27^{\circ} C$,$500 \ mL$ of helium diffuses in $30 \ minutes$. What is the time (in hours) taken for $1000 \ mL$ of $SO_2$ to diffuse under the same experimental conditions?

If the charge on the capacitor is increased by $2 \ C$,the energy stored in it increases by $21 \%$. The original charge on the capacitor is: (in $C$)