The question asks for the resonance frequency ($f_0$) of a series AC circuit containing a resistor (R), capacitor (C), and inductor (L).
The resonance frequency in an RLC circuit is the frequency at which the inductive reactance equals the capacitive reactance. It is independent of the resistance and is calculated using the formula:
$f_0 = \frac{1}{2\pi\sqrt{LC}}$
Given values are:
$f_0 = \frac{1}{2\pi\sqrt{(1 \times 10^{-3} \text{ H}) \times (1 \times 10^{-7} \text{ F})}}$.
$LC = 1 \times 10^{-10} \text{ H}\cdot\text{F}$
$\sqrt{LC} = \sqrt{1 \times 10^{-10}} = 1 \times 10^{-5} \text{ s}$
$f_0 = \frac{1}{2\pi \times (1 \times 10^{-5})} = \frac{10^5}{2\pi} \text{ Hz}$
Using $\pi \approx 3.14159$,
$f_0 \approx \frac{100000}{2 \times 3.14159} \approx \frac{100000}{6.28318} \approx 15915.5 \text{ Hz}$
$f_0 \approx 15.9155 \text{ kHz}$
The calculated resonance frequency is approximately $15.9 \text{ kHz}$.
A 100-turn closely wound circular coil of radius $10 \text{ cm}$ has a magnetic field of $3.14 \times 10^{-3} \text{ T}$ at its centre. The current passing through the coil, and the magnitude of the magnetic moment of this coil are, respectively :
(Take $\mu_0 = 4\pi \times 10^{-7} \text{ T m/A}$)
The figure given below shows a long straight solid wire of circular cross-section of radius 'a' carrying steady current I. The current I is uniformly distributed across its cross-section. The plot which correctly represents the variation of magnetic field (B) with distance (r) from the axis of the conductor in the region is :
Five capacitors of capacitances $C_1 = C_2 = C_3 = C_4 = 10 \ \mu\text{F}$ and $C_5 = 2.5 \ \mu\text{F}$ are connected as shown along with a battery of $50 \text{ V}$. 
The equivalent capacitance and the charges on each capacitor respectively are :
A uniform metallic wire having resistance $4 \ \Omega$ is bent to form a square loop ABCD. A resistance of $2 \ \Omega$ is connected between points B and D and a battery of $2 \text{ V}$ is connected across points A and C as shown in the figure. Now the value of current (I) is :
Match List I with List II :
| List I (Electromagnetic wave) | List II (Production) |
| A. Microwave | I. Electrons in atoms emit light when they move from a higher energy level to a lower energy level |
| B. Visible light | II. Radioactive decay of nucleus |
| C. Gamma rays | III. Vibration of atoms and molecules |
| D. Infra-red ray | IV. Klystron valve or magnetron valve |
Choose the correct answer from the options given below :