Ans: 3
2071 set d q. no. 12 2069 supp set b q. no. 122069 set b
q. no. 12 a parallel beam of sodium light is incident normally
on a diffraction grating. the angle between the two first order
spectra on either side of the normal is 27°42'. assuming that
the wavelength of light is 5.893 x 10-7m, find the number of
rulings per mm on the grating?
ans: 406 lines/mm

What are two different ways you could find the value of a? explain these methods.

The temperature at a point (x, y) is t(x, y), measured in degrees celsius. a bug crawls so that its position after t seconds is given by x = 6 + t , y = 8 + 1 3 t, where x and y are measured in centimeters. the temperature function satisfies tx(3, 9) = 5 and ty(3, 9) = 4. how fast is the temperature rising on the bug's path after 3 seconds? (round your answer to two decimal places.)

Name two kinds of practical electric pumps.