$A$ $4\,\mu F$ capacitor is charged to $400\,V$ and then its plates are joined through a resistance of $1\,k\Omega$. The heat produced in the resistance is ............... $J$.

$A$ resistance $R$ and a capacitance $C$ are connected in series to a battery of negligible internal resistance through a key. The key is closed at $t = 0$. If after $t \, s$ the voltage across the capacitance is seven times the voltage across $R$,the value of $t$ is:

In an experiment with a $C-R$ circuit,two identical capacitors,a resistor,and a $6V$ voltage source are used. For the parallel combination of capacitors,the time required for the voltage to reach half of its fully charged value is $10 \ s$. For the series combination,the time required for the voltage to reach half of its fully charged value is ...... $s$.

$A$ resistor $R$ and a $2 \ \mu F$ capacitor in series are connected through a switch to a $200 \ V$ direct supply. Across the capacitor is a neon bulb that lights up at $120 \ V$. Calculate the value of $R$ to make the bulb light up $5 \ s$ after the switch has been closed. (Given: $\log_{10} 2.5 = 0.4$)

The charge across the capacitor in two different $RC$ circuits $1$ and $2$ are plotted as shown in the figure. Identify the correct statement$(s)$ related to the $R_1, R_2, C_1$ and $C_2$ of the two $RC$ circuits.

Which of the following is a possible application of an $RC$ circuit?