pl help Q 19
pl help Q 19 RAY OPTICS
17. COLUMN - 1
A) A convex lens in a denser medium will behave like a
B) A concave lens in a rarer medium will behave like a
C) A piano-convex lens silvered on its curved surface
and placed in air will behave like a
D) A planoconcave lens silvered on its plane surface
and placed in air will behave like a
Section - D
Integer Type Questions
o
COLUMN - 11
p) converging lens
q) diverging lens
r) concave mirror
s) convex mirror
is filled in the tank upto a height
4
The flat bottom of cylinder tank is silvered and water
bottom of the tank. When a small hole is opened near the bottom of the tank, the water level falls at
the rate of 1 cm/s. The bird will perceive that his velocity of image is l/x cm/sec (in downward
directions) where x is
19. A small air bubble is situated at a distance of 3 cm from the centre of a glass sphere of radius 9cm,
When viewed from the nearest side, the bubble appears to be at a distance of 5cm from the sphere.
Its apparent distance when viewed from the farthest side is n x 5 cm where n is ?
20. A cubical block of glass, refractive index 1.5, has a spherical cavity of radius r = 9 cm inside it as
shown in figure. A luminous point object O is at a distance of 18crn from the cube (see figure) What
is the apparent position of O as seen from A is 8.5 x cm to the left ofS4 then x is
o
18cm 9cm 18cm 9cm
. The focal length of a thin biconvex lens is 20cm when an object is moved from a distance 25cm in
25
is
front of it to 50cm. the magnification of its image changes from to rnso . The ratio
22. An object is kept at a distance of 16cm from a thin lens and the image formes is real. Ifthe object is
kept at a distance of 6cm from the same lens, the image formed is virtual. If the sizes, of the images
formed are equal, the focal length of the lens will be I lx cm find x value