CBSE Guess > Papers > Important Questions > Class XII > 2013 > Physics > Physics - by Mr. Raghu Sharma
CBSE CLASS XII
Physics
- Name the device which works under the principle of velocity selector?
- Define 1 Ampere the unit of a.c current and how does it vary from d.c current?
- Is the magnitude of displacement current less, equal or greater than the conduction current?explain
- a)Why secondary rainbow is fainter than the primary rainbow? b) why clouds are appearing white?
- In a wave picture of light, the intensity of light is determined by square of amplitude of wav e. What determines the intensity of light in photon picture of light?
- The maximum K.E of emitted photo electron is 15eV. Find its stopping potential.
- Draw a graph to show the variation of impact parameter (in alpha particle scattering)with scattering angle Ѳ.
- Name a communication channel which can offer a transmission bandwidth in excess of 100 GHZ.
- If accelerating voltage of anode is doubled what will be the change in De Broglie’s wave length of electron?
- Waves from which portion of EM spectrum are utilized to identify defects in crystals. Write the frequency range corresponding to this zone
- Why does the electric field inside a dielectric decrease when it is placed in an external electric field?
- Draw the symbol and write truth table of NOR gate.?
- A wire is stretched to double its length. What will be the effect on its resistivity ?
- Two thin lenses of power +7D and -3D are in contact. What is the focal length of the combination ?
- The radii of curvature of the faces of a double convex lens are 10 cm and 15 cm. If focal length is 12 cm, what is the refractive index of glass ?
- What is the distance of closest approach when a 5.0 MeV proton approaches a gold nucleus?
- It is observed that only 6.25% of a given radioactive sample is left undecayed after a period of 16 days. What is the decay constant of this sample, in day-1 ?
- For a transistor connected in common emitter mode, the voltage drop across the collector is 2 V and β is 50. Find the base current, if RC is 2 K
- State the reason , why GaAs is most commonly used in making of a solar cell.
- A square wave is applied to p-n junction diode as shown in the figure. Draw the output waveform.
Submitted By : Mr. Raghu Sharma
Email: [email protected]
