QUESTION PAPER 11

1. a)Define the following terms w.r.to hygrometry
i) Vapour pressure ii)Dew point temperature. (7)
b)Explain Dry and wet hygrometer. (7)
2. a)Light of wavelength 3500 Å is incident on two metals A and B.which metal will yield
photoelectrons if their work functions are 4.2 eV and 1.9 eV respectively. (7)
b)Explain relative and absolute humidity w.r.to hygrometry. (7)
3. a)Explain with neat diagram,construction and working of Sextant. (7)
b)Give the applications of Optical fibre in medical field. (7)
4. a)Explain with neat diagram,construction and working of azimuthal mirror. (7)
b)If a photoemissive surface has a threshold frequency of 4.6× 1014 HZ,calculate the energy of the
photons in eV.Given h= 6.6 × 10-34 Js. (7)
5. a)How does a ship’s echo sounder work? (7)
b)A sparrow chases a crow with a speed of 4 m/s,while chirping at a frequency of 850 Hz.What
frequency of sound does the crow hear as he fires away from the sparrow with a speed of 3 m/s?(7)
6. a)Discuss the characteristics of musical sound. (7)
b)i)Density of air at a pressure of 105 N/m2 is 1.21 kg/m3.if ¥= 1.4, calculate the velocity of sound in air.
ii)Density and pressure of gas are 1.98 kg/m3 and 1.013 ×105 N/m2 respectively.if the adiabatic
constant is 1.41, calculate the wavelength of sound of frequency 1000 Hz. (7)
7. a)Explain h-S chart(mollier diagram) in detail. (7)
b)Define the following.
Heat engine & Refrigerator. (7)
8. a) State first and second law of thermodynamics. (7)
b) Air expands from 11 bar at 550°C to a pressure of 3 bar adiabatically. determine temperature at the
end of expansion and work done. find also the change in entropy. (7)