Of petrol is 11 x 103 kcal per kg calculate the entienu
[4]
the engine.
ans: 31.15%
18.
unit 3: geometric optics
1. reflection at curved mirrors
19.
formulae
l os
1. relationship between focal length and radius of
curvature , f= .
2
1
1
n
2. mirror formula,
+
< 1
<
3. magnification, m = ñ
= u
<
short answer questions
1. 2074 set b q. no. 3a use graphical method to locate image of
an erect object placed before a concave mirror between its
pole and the focus. hence write down the nature of image so
formed.
[2]

Asheet of steel 1.5 mm thick has nitrogen atmospheres on both sides at 1200oc and is permitted to achieve a steady-state diffusion condition. the diffusion coefficient for nitrogen in steel at this temperature is 6 x 10- 11 m2 /s, and the diffusion flux is found to be 1.2 x 10-7 kg/m2 -s. also, it is known that the concentration of nitrogen in the steel at the high-pressure surface is 4 kg/m3 . how far into the sheet from this high-pressure side will the concentration be 2.0 kg/m3 ? assume a linear concentration profile.