Using a variable frequency a.c. voltage source the maximum current measured in the given LCR circuit is 50 mA for $V = 5\sin(100t)$ The values of L and R are shown in the figure. The capacitance of the capacitor (C) used is ___________ $\mu\text{F}$. 
To find the capacitance \(C\) in the given LCR circuit, follow these steps:
The maximum current \(I_{\text{max}}\) is given as \(50 \, \text{mA} = 0.05 \, \text{A}\).
The voltage across the circuit is \(V = 5 \sin(100t)\), so the peak voltage \(V_0 = 5 \, \text{V}\).
The angular frequency \(\omega\) is \(100 \, \text{rad/s}\).
For maximum current, the circuit is at resonance: \(Z = \frac{V_0}{I_{\text{max}}}\), where \(Z\) is the impedance. So, \(Z = \frac{5}{0.05} = 100 \, \Omega\).
At resonance in an LCR circuit, \(Z = R\), meaning \(R = 100 \, \Omega\).
The resonance condition is \(\omega L = \frac{1}{\omega C}\), where \(L = 2 \, \text{H}\).
Thus, \(\omega^2 = \frac{1}{LC}\). Substituting the known values, \(100^2 = \frac{1}{2C}\).
Solve for \(C\):
\(C = \frac{1}{2 \times 10000} = \frac{1}{20000} = 50 \times 10^{-6} \, \text{F} = 50 \, \mu\text{F}\).
The calculated capacitance \(C = 50 \, \mu\text{F}\), which falls within the expected range of [50, 50].
The space between the plates of a parallel plate capacitor of capacitance C (without any dielectric) is now filled with three dielectric slabs of dielectric constants $K_1 = 2$, $K_2 = 3$ and $K_3 = 5$ (as shown in figure). If new capacitance is $\frac{n}{3}C$ then the value of $n$ is ___________. 
Combination of four parallel plate air capacitors is shown in figure. Separation between the plate P1 & P2 is $\frac{d}{3}$ and separation between the plates P2 and P3 is d.
The equivalent capacitance of the configuration is _____________$\mu$F.
(Given $\frac{\epsilon_0 A}{d} = 4\mu$F . Where A=Area of plates)

A copper rod of mass m slides under gravity on two smooth parallel rails, with separation $l$ and set at an angle of $\theta$ with the horizontal. At the bottom, rails are joined by a resistance R. There is a uniform magnetic field B normal to the plane of the rails, as shown in the figure. The terminal speed of the copper rod is :

The space between the plates of a parallel plate capacitor of capacitance C (without any dielectric) is now filled with three dielectric slabs of dielectric constants $K_1 = 2$, $K_2 = 3$ and $K_3 = 5$ (as shown in figure). If new capacitance is $\frac{n}{3}C$ then the value of $n$ is ___________. 