Pre Boards

Practice to excel and get familiar with the paper pattern and the type of questions. Check you answers with answer keys provided.

Sample Papers

Download the PDF Sample Papers Free for off line practice and view the Solutions online.

ISC Class 12 Physics Solved Question Paper 2011

Short Answer Type

41. Starting with the law of radioactive disintegration, show that : N = N₀e^{-λ t,} where the terms have their usual meaning.

605 Views

42. What is meant by Pair Production ? Explain with the help of an example and a balanced equation.

748 Views

43.

An X ray tube is operated at a tube potential of 40,000 V. Calculate :

(i) Kinetic energy of an electron emitted by the filament when it reaches the target / anode.

(ii) Wavelengths of all the X rays emitted by the X ray tube.

496 Views

44. (i)In the following nuclear reaction, calculate the energy released in MeV :

straight H presubscript 1 presuperscript 2 space plus space straight H presubscript 1 presuperscript 2 space rightwards arrow space He presubscript 2 presuperscript 3 space plus space straight n presubscript 0 presuperscript 1

Given that: Mass of

straight H presubscript 1 presuperscript 2

= 2.015 u
Mass of

He presubscript 2 presuperscript 3 space equals space 3.017 space straight u

Mass of on = 1.009u

(ii) What is the name of this reaction ?

1020 Views

45.
What is meant by the terms :

(i) a full wave rectifier ?

(ii) an amplifier ?

(iii) an oscillator ?

(i)Full wave rectifier : It converts alternating current into direct current. In this complete conversion of a.c. to d.c. takes pipe.

(ii) An amplifier : A device which amplify a signal. A junction diode cannot amplify a signal. A transistor consisting of two p-n junctions one toward biased and the other reverse bias is used to amplify a weak signal.

(iii) An oscillator : It is a device that generates electrical oscillations of constant amplitude and of desired frequency, without any external input.

161 Views