Optics Answers

Determine the focal length of a thin converging lens if the power is 5.0 dioptres

9.Which of the following is not a right precaution in experiment to determine the refractive index of glass?
a.The two pins erected should NOT be straight.\n\n
b.The position of the glass slab should not be disturbed.
c.The slope should be taken carefully.\n
d.\nImages of the fisrt two pins should be in the straight line with the other two pins.\n\n

10.Which of these precautions must be ensured in an experiment to verify Snell\'s law?
a.the pins are in line\nbefore placing the glass block
b.the pins are mounted on the optical bench before placing the glass block
c.the pins are in line\nbefore removing the glass block
d.the pins are mounted on the optical bench before removing the glass block

7.All the following are required as apparatus in refraction using glass block experiment EXCEPT
a.G-Clamp
b.Drawing board
c.Optical pins
d.Thumb tacks

8.The mirror formula relates I- focal length of the mirror II- object distance III- image distance IV- principal focus
a.I, III and IV only
b.II, III and IV only
c.I, II and IV only
d.I, II and III only

5.Convex mirror is a curved\nmirror which is silvered_______________
a.in and out side
b.from inside
c.None of the above
d.in its outer side

6.What is the bending of a ray of light when it travels through a medium called?
a.refraction
b.reflection
c.rectilinear propagation of light
d.diffraction

3.What is the bending of a ray of light when it travels through a medium called?
a.reflection
b.rectilinear propagation of light
c.refraction
d.diffraction

4.Concave mirror is a curved\nmirror which is silvered_______________
a.in its outer side
b.in and out side
c.None of the above
d.from inside

1.Which of the following is required in an experiment to determine the focal length of a mirror?
a.Optical bench
b.Mounted pins.
c.All of the above
d.Concave mirror with holder

2.Which of the following experiments can be suitably used to practically verify the laws of refraction?
a.None of the above
b.Refraction through the glass block experiment
c.Refraction experiment by plano-convex lens
d.Refraction experiment by triangular glass prism

A person can see clearly objects lying between 15cm and 100cm from the eye.what will be the range of his vision if he wears close fitting spectacles having a power of 0.8 D?

If your eye glasses have focal length 60cm what is your near point?

In a double slit experiment, the two slits are 1 mm apart and the screen is placed 1 m away A monochromatic light of wavelength 500 nm is used. What will be the width of each slit for obtaining ten maxima of double slit within the central maxima of single slit pattern? (a) 0.5 mm (b) 0.02 mm (c) 0.2 mm (d) 0.1 mm

In an astronomical telescope in normal adjustment a straight black line of length L is drawn on inside part of objective lens. The eye-piece forms a real image of this line. The length of this image is I. The magnification of the telescope is
(a) L+I/L-I
(b) L/I
(c) L/I+1
(d) L/I-1