Calendar: 1871-1872 Page 537

APPLIED SCIENCES 537 any facts in the absorption of light which at first sight do not appear to be in accordance with this theory What is meant by the conductivity of bar Describe some accurate method of determining the conductivity of bar of metal Define specific heat Describe the method of measuring specific heat called the method of mixtures What relation exists between the specific heat and the atomic weight of bodies What conclusion would you draw with regard to their atoms Explain the principle of the kaleidoscope If there are two plane mirrors and they are inclined at an angle of 60 how many images of the same point will be seen and how will they be situated Find the relation which gives the position of the principal focus when parallel rays fall upon lens How would you determine the focal length of lens experimentally Parallel rays fall on semicircular mirror show that the caustic formed by the intersection of the reflected rays is an epicycloid formed by the rolling of one circle on another equal circle 10 When ray passes through prism refracting angle with minimum deviation show that sin sj In what way is it possible by means of prisms to obtain deviation without dispersion Point out the bearing of this fact on the construction of optical instruments 11 Trace pencil of rays through the astronomical telescope with Huyghens' eyepiece and explain why this eyepiece cannot be used for accurate measurement 12 Describe the solar spectrum and explain its peculiarities and the relation which it bears to the spectra of incandescent solids liquids and gases What conclusions can be drawn from it as to the nature 01 the Sun