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ISC Class 12 Physics Solved Question Paper 2009

Short Answer Type

41.

A sinusoidal voltage e = e₀ Sin (wt) is fed to a common emitter amplifier. Draw neatly labelled diagrams to show:

(i) Signal voltage

(ii) Output voltage of the amplifier.

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42. Make a truth table showing inputs at A and B and outputs at X, Y and Z for the combination of gates shown in figure below:

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Long Answer Type

43. With the help of a labelled diagram, obtain an expression for the electric field intensity ‘E’ at a point P in broad side position (i.e., equatorial plane) of an electric dipole.

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44. What is meant by ‘Chromatic aberration’? A thin convex lens of focal length 30 cm and made of flint glass (dispersive power = 0.03) is kept in contact with a thin concave lens of focal length 20 cm and made of crown glass. Calculate the dispersive power of crown glass if the above said combination acts as an achromatic doublet.

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45.
Electrons, initially at rest, are passed through a potential difference of 2 kV. Calculate their:

(i) Final velocity and

(ii) de Broglie wavelength.

i) Final velocity, v = $square root of fraction numerator 2 cV over denominator straight m end fraction end root space equals space square root of fraction numerator 2 space x space 1.6 space x space 10 to the power of negative 19 end exponent space x space 2 space x space 10 cubed over denominator 9 space x space 10 to the power of negative 11 end exponent end fraction end root$

v = 7.1 x 10¹⁵ m/s

ii) De-broglie wavelength, $straight lambda$ = $fraction numerator 12.27 over denominator square root of straight V end fraction space A with o on top space equals space fraction numerator 12.27 over denominator square root of 2 space x space 10 cubed end root end fraction A with o on top space equals space 0.272 space A with o on top$