...the mirror ; if the mirror be convex it will be also towards the surface. 32. To find the geometrical focus of a pencil of rays after direct refraction at a spherical surface. Let Q (fig. 17) be the origin of a pencil of light whose axis QA is incident directly on a spherical...

...15.— Morning, lOtol. OPTICS— HEAT— ASTRONOMY. Examiner, Mr. JERRARD. 1 . Find the geometrical focus of a pencil of rays after direct refraction at a spherical surface. 2. A pencil of light passes centrically with small obliquity through two thin lenses in contact, to...

...vertex upwards and axis vertical ; determine the density of the air contained in the hollow cone. 2J. A sphere composed of two hemispheres of different...is placed in the path of a pencil of light in such manner that the axis of the pencil is perpendicular to the plane of junction and passes through the...

...feet deep to a person looking directly down upon it. (fj, = -f for water.) (A). Find the geometrical focus of a pencil of rays after direct refraction at a spherical refracting surface. (B}. Rays are incident parallel to the axis on a glass cylinder with hemispherical...

...meet the surface in the same point; find the angle of incidence when p = -—-— . , 3 + ^5 m 35. A sphere composed of two hemispheres of different...determine the geometrical focus of the refracted pencil. 36. Find the geometrical focus of a pencil of rays refracted through a hollow glass sphere, whose external...

...normal to the surface ; otherwise the refraction is said to be oblique. In order to find the geometrical focus of a pencil of rays after direct refraction at a spherical surface, let r, Fig. 579, be the origin of a pencil of light in- p • 579 cident directly on a spherical refracting...

...MATHEMATICS. (B.) Professor HJS SMITH. Wednesday, 24th March 1875. 10 AM to 1 PM 1. Find the geometrical focus of a pencil of rays after direct refraction at a spherical surface. A, B, are two radiant points situated very near to one another on the axis of a concave spherical mirror...

...? IX. Show that there cannot be more than three lunar eclipses in the year. X. Find the geometrical focus of a pencil of rays after direct refraction at a spherical surface. o Ex. refractive index = - ; rays incident on a concave mirror whose radius is 5 ft.; distance of the...

...see the image F' shut, and if E be shut, F will see the image E' shut viii. Determine the geometrical focus of a pencil of rays after direct refraction at a spherical refracting surface. A hollow globe of glass has a speck on its interior surface, if this be observed...

...and are proportional to the times of describing them. Optics and Astronomy. 4. Find the geometrical focus of a pencil of rays after direct refraction at a spherical surface, and trace the relative changes of position of the conjugate foci. 5. A plane surface touches a self-luminous...