Four identical condensers are connected in parallel and then in series equivalent capacitance in series to that in parallel combination is
Let's denote the capacitance of each individual capacitor as C. Then, the equivalent capacitance in parallel, Cp, is given by:
Cp = 4C
Now, when capacitors are connected in series, the reciprocal of the equivalent capacitance is equal to the sum of the reciprocals of the individual capacitances.
For our case, since we have four identical capacitors connected in series, the equivalent capacitance in series, Cs, is given by:
\(\frac {1}{C_s}\) = \(\frac {1}{C}\) + \(\frac {1}{C}\)+ \(\frac {1}{C}\) + \(\frac {1}{C}\)
\(\frac {1}{C_s}\) = \(\frac {4}{C}\)
Taking the reciprocal of both sides, we get:
Cs = \(\frac {C}{4}\)
Therefore, the ratio of the equivalent capacitance in series to that in the parallel combination is:
\(\frac {C_s}{C_p }\)= \(\frac {\frac {C}{4}}{4C}\)
\(\frac {C_s}{C_p } \) = \(\frac {1}{16}\)
The correct answer is (D) 1 : 16.
Two capacitors \( C_1 \) and \( C_2 \) are connected in parallel to a battery. Charge-time graph is shown below for the two capacitors. The energy stored with them are \( U_1 \) and \( U_2 \), respectively. Which of the given statements is true? 
In a Young's double slit experiment, three polarizers are kept as shown in the figure. The transmission axes of \( P_1 \) and \( P_2 \) are orthogonal to each other. The polarizer \( P_3 \) covers both the slits with its transmission axis at \( 45^\circ \) to those of \( P_1 \) and \( P_2 \). An unpolarized light of wavelength \( \lambda \) and intensity \( I_0 \) is incident on \( P_1 \) and \( P_2 \). The intensity at a point after \( P_3 \), where the path difference between the light waves from \( S_1 \) and \( S_2 \) is \( \frac{\lambda}{3} \), is:

Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R).
Assertion (A): Choke coil is simply a coil having a large inductance but a small resistance. Choke coils are used with fluorescent mercury-tube fittings. If household electric power is directly connected to a mercury tube, the tube will be damaged.
Reason (R): By using the choke coil, the voltage across the tube is reduced by a factor \( \frac{R}{\sqrt{R^2 + \omega^2 L^2}} \), where \( \omega \) is the frequency of the supply across resistor \( R \) and inductor \( L \). If the choke coil were not used, the voltage across the resistor would be the same as the applied voltage.
In light of the above statements, choose the most appropriate answer from the options given below:
The total capacitance of this equivalent single capacitor depends both on the individual capacitors and how they are connected. There are two simple and common types of connections, called series and parallel, for which we can easily calculate the total capacitance.
Read Also: Combination of Capacitors
When one terminal of a capacitor is connected to the terminal of another capacitors , called series combination of capacitors.
Capacitors can be connected in two types which are in series and in parallel. If capacitors are connected one after the other in the form of a chain then it is in series. In series, the capacitance is less.
When the capacitors are connected between two common points they are called to be connected in parallel.
When the plates are connected in parallel the size of the plates gets doubled, because of that the capacitance is doubled. So in a parallel combination of capacitors, we get more capacitance.
Read More: Types of Capacitors