Class 12 > PYQ PHYSICS > 2015 > Set 1

2015

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Q11
Use Kirchhoff's rules to obtain conditions for the balance condition in a Wheatstone bridge.

Q12
Name the parts of the electromagnetic spectrum which is
(a) suitable for radar systems used in aircraft navigation.
(b) used to treat muscular strain.
(c) used as a diagnostic tool in medicine.
Write in brief, how these waves can be produced.

Q13
(i) A giant refracting telescope has an objective lens of focal length 15 m. If an eye piece of focal length 1.0 cm is used, what is the angular magnification of the telescope?
(ii) If this telescope is used to view the moon, what is the diameter of the image of the moon formed by the objective lens? The diameter of the moon is 3.48 × 10⁶ m and the radius of lunar orbit is 3.8 × 10⁸ m

Q14
Write Einstein's Photoelectric equation and mention which important features in photoelectric effect can be explained with the help of this equation.

Q15
In the study of Geiger-Mrasdon experiment on scattering of ⍺- particles by a thin foil of gold, draw the trajectory of ⍺- particles in the Coulomb field of target nucleus. Explain briefly how one gets the information on the size of the nucleus from this study.

Q16
Distinguish between nuclear fission and fusion. Show how in both these processes energy is released.

Q19
Two capacitors of unknown capacitances C₁ and C₂ are connected first in series and then in parallel across a battery of 100 V. If the energy stored in the two combinations is 0.45 J and 0.25 J respectively, determine the value of C₁ and C₂. Also calculate the charge on each capacitor in parallel combination.

Q20
State the principle of working of a galvanometer.

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