CBSE PHYSICS SAMPLE PAPER
Time : 3 hrs. M.M. 70
Section A [5X1=5]
- Which of the physical quantities have the unit (a) V/m & (b) C/m.
- What is the full form of FAX?
- What is Seebeck effect?
- What is the direction of magnetic dipole moment?
- State Lenz’s law.
Section B [7X2=14]
- Why two electric lines of force can never intersect? Explain.
- State Faraday’s laws of electrolysis.
- Why 220V a.c. is more shocking than 220Vd.c.; explain?
- What is total internal reflection? State the conditions necessary for it.
- Give two distinctions between interference and diffraction.
- The work function of cesium is 2.14eV. Find the wavelength of the incident photon if the photo current is brought to zero by a stopping potential of 0.60V. Given h=6.63X10-34 Js.
- Define depletion region and potential barrier.
Section C [12X3=36]
- Draw a labelled circuit diagram for a common emitter amplifier using n-p-n transistor. Explain the phase relationship between input and output signals for it.
- Give the logic symbol & truth table for (a) XOR gate & (b) AND gate.
- Calculate the binding energy per nucleon in case of 26Fe56. Given:- mass of proton = 1.007825amu, mass of neutron = 1.008665amu and mass of nucleus of 26Fe56 is 55.934939amu.
- What is photoelectric emission? State the laws of photoelectric emission.
- Define half-life of a radioactive substance. Deduce an expression for it.
- Derive the conditions for constructive and destructive interference.
State and explain Huyghen’s principle. Name the type of wave front that corresponds to a beam of light
(i) coming from a convex lens when point source lies at its focus
(ii) coming from a very far off source.
(iii) diverging radially from a point source
- Derive an expression for the magnifying power of an astronomical telescope when the final image is at least distance of distinct vision.
- What does ‘remote sensing’ mean? Explain breifly how it is carried out? Mention its two applications.
A T.V. transmission tower at a particular station has a height of 160m. (a) What is its coverage range? (b) How much population is covered by transmission if the average population density around the tower is 1200 km-2? Given radius of earth = 6400 km.
- Give the principle and construction of moving coil galvanometer.
- A circular coil of 500 turns has a radius of 2m and carries a current of 2A. What is the magnetic field at a point on the axis of the coil at a distance equal to the radius of the coil from the centre?
- With a circuit diagram explain how the potentiometer can be used to compare the E.M.Fs of two cells.
- A wire of resistance 5 ohm is drawn out so that its length is increased by three times of its original length. Calculate its new resistance & resistivity.
Section D [3X5=15]
- With the help of labelled diagram explain the principle and working of Van-de-Graff generator.
- Explain the principle, construction and working of a.c. generator
Explain the principle & theory of transformer. Discuss various energy losses involved in a transformer.
- With the help of block diagram, explain the communication satellite link for long distance calls. Give its two advantages.