Q. Give the basic function of antenna.

Q. A common emitter (CE) transistor has a current gain of $100$. If emitter current is $8.08mA$, find the base an collector current.

Q. With the help of ray diagram, describe the construction, working of a compound microscope when the final image is formed at least distance of distinct vision $(D=25cm)$. Derive an expression fords magnifying power (m).

Q. What is the essential condition for diffraction of light to occur?

Q. Why two electric lines of force/field cannot intersect each other?

Q. What is internal reflection of light ?What ate the two essential conditions for total internal reflection to take place?

Q. Explain ground wave propagation.

Q. What are diamagnetic substances?

Q. A solenoid of length $50cm$, having $100$ turns carries a current of $2.5A$. Find the magnetic field (B), (a) in the interior of teh solenoid, (b) at one end of the solenoid. Given ${\mu }_0=4\pi \times {10}^{-7}Wb{A}^{-1}{m}^{-1}$.

Q. What is the de-Broglie wavelength of an electron beam accelerated through a potential difference of $25V$?

Q. In a sample of semi conductor mobilities of electrons and holes are $24\times {10}^{3}c{m}^2{V}^{-1}{S}^{-2}$ and $0.2\times {10}^{3}c{m}^2{V}^{-1}{S}^{-1}$ respectively. If the density electrons is $0.8\times {10}^{14}c{m}^{-3}$ and that of holes is $0.4\times {10}^{14}c{m}^{-3}$. Find the nature of semi conductor and its conductivity.

Q. A capacitor of unknown value and an inductor of $0.1H$ and a resistor of $10\Omega$ are connected in series to a $220V,50Hzac$ source. It is found that the power factor of circuit is unity. Calculate the capacitance of capacitor and maximum amplitude of current.

Q. Why does the sky appear blue?

Q. What is rectifier? Explain the working of p-n junction diode as a full-wave rectifier with the help of suitable circuit diagram.

Q. Define resonant frequency of LCR series circuit.

Q. Why does the thickness of depletion layer of pn-junction increases in reverse biasing ?Draw the circuit diagram of reverse biasing.

Q. With the help of labelled diagram, describe principle, construction and working of a transformer.

Q. Give two uses of Infrared Rays.

Q. Name a phenomenon which illustrates the particle nature of light.

Q. Write the truth table of AND gate.

Q. What is the shape of equipotential surface for a given point charge $q$.

Q. Define e.m.f. of a cell. How can you compare the emf of two cells using potentiometer?

Q. ______ was the first scientist who produced electromagnetic waves in a laboratory.

Q. A wire with an area of cross-section as $10m{m}^2$ has a resistance of $5\Omega$, when a potential difference across its ends is $25V$. Calculate the drift velocity of electrons. Given the number density of electrons as $5\times {10}^{20}$ electrons per cubic meter $\left(e/m^{-3}\right)$.

Q. Two lenses of powers $+15D$ and $-5D$ are in contact with each other. What is the focal length of combination?

Q. Derive an expression for the energy seated in a capacitor. In what form is the energy stored in a charged capacitor?

Q. State the laws of photo electric effect.

Q. How can a galvanometer be converted into an ammeter?

Q. How the eye of a person suffering from myopia can be corrected? Explain with the help of a ray diagram.

Q. Write SI unit of magnetic dipole moment.