Download App

MODEL PAPER 2 — Physics STD 12 Science — Question

Bihar BoardEnglish MediumSTD 12 SciencePhysicsMODEL PAPER 23 Marks
Question
i. Define the term self-inductance and write its S.I. unit.
ii. Obtain the expression for the mutual inductance of two long co-axial solenoids $S_1$ and $S_2$ wound one over the other, each of length $L$ and radii $r_1$ and $r_2$ and $n_1$ and $n_2$ number of turns per unit length, when a current $I$ is set up in the outer solenoid $S _2$.
✓

Answer

i. Self-Inductance is the property by which an opposing induced emf is produced in a coil due to a change in current, or magnetic flux, linked with the coil.
ii. In this question, a long co-axial solenoids $S_1$ and $S_2$ wound one over the other, each of length $L$ and radii $r_1$ and $r_2$ and $n_1$ and $n _2$ number of turns per unit length, when a current I is set up in the outer solenoid $S _2$.
Image

Let a current $l_2$ flow in the secondary coil
$\therefore B _2=\frac{\mu_0 N_2 i_2}{t}$
$\begin{array}{l}\therefore \text { Flux linked with the primary coil }=\frac{\mu_0 N_2 N_1 A_1 i_2}{l} \\ = M _{12} i _2\end{array}$
Hence, $M _{12}=\frac{\mu_0 N_2 N_1 A_2}{l}$
$\mu_0 n_2 n_1 A_1 l\left(n_1=\frac{N_1}{l} ; n_2=\frac{N_2}{l}\right)$

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free

Explore more

More "3 Marks Question" from MODEL PAPER 2→MODEL PAPER 2 — all question types→Physics STD 12 Science question papers→Bihar Board STD 12 Science question papers→Bihar Board question paper generator→

Similar questions

A battery of $10 V$ and negligible internal resistance is connected across the diagonally opposite corners of a cubical network consisting of 12 resistors each of resistance $1 \Omega$ (Fig. 3.16). Determine the equivalent resistance of the network and the current along each edge of the cube.
Image
→
State two characteristic properties distinguishing the behaviour of paramagnetic and diamagnetic materials ?
→
Which wavelengths will be emitted by a sample of atomic hydrogen gas (in ground state) if electrons of energy 12.2eV collide with the atoms of the gas?
→
A simple pendulum consists of a 50cm long string connected to a 100g ball. The ball is pulled aside so that the string makes an angle of 37° with the vertical and is then released. Find the tension in the string when the bob is at its lowest position.

→
The relative luminosity of wavelength 600nm is 0.6. Find the radiant flux of 600nm needed to produce the same brightness sensation as produced by 120W of radiant flux at 555nm.
→
Obtain expression $\vec{J}=\sigma \vec{E}$ of Ohm's law on the basis of drift velocity.
→
A magnifying glass is a converging lens placed close to the eye. A farsighted person uses spectacles having converging lenses. Compare the functions of a converging lens used as a magnifying glass and as spectacles.
→
The index of refraction of fused quartz is 1.472 for light of wavelength 400nm and is 1.452 for light of wavelength 760nm. Find the speeds of light of these wavelengths in fused quartz.
→
  1. The refractive index of glass is 1.5. What is the speed of light in glass? (Speed of light in vacuum is 3.0 × 108 ms–1).
  2. Is the speed of light in glass independent of the colour of light? If not, which of the two colours red and violet travels slower in a glass prism?
→
$\text{ }^{197}_{80}\text{Hg}$ decay to $\text{ }^{197}_{79}\text{Au}$ through electron capture with a decay constant of 0.257 per day.
  1. What other particle or particles are emitted in the decay?
  2. Assume that the electron is captured from the K shell. Use Moseley's law $\sqrt{\text{v}}=\text{a(Z}-\text{b})$ with $\text{a}=4.95\times10^7\text{s}^{-\frac{1}{2}}$ and b = 1 to find the wavelength of the $\text{K}_{\alpha}$ X-ray emitted following the electron capture.
→