# 15 - Optics Questions Answers

Physics >> Optics >> Refraction IIT JEE Dear Sir request if you can help provide solution.
Asked By: RK GUPTA
Asked By: KANDUKURI ASHISH
Joshi sir comment

A boy is walking under an inclined mirror at a constant

velocity V m/s along the x-axis as shown in figure. If the

mirror is inclined at an angle θ with the horizontal then

what is the velocity of the image?

Asked By: ASHISH JOSEPH
Joshi sir comment
Physics >> Optics >> Refraction IIT JEE
Joshi sir comment

Can You Please Explain the Cartesian method for mirror and Lens?

Asked By: BONEY HAVELIWALA
Joshi sir comment

Cartesian method is the method of sign convention

Sign Convention for Spherical Mirrors and Thin Lenses

Spherical Mirrors                   Lenses
Focal Length            - for concave mirrors            + for a converging lens
+ for convex mirrors               - for a diverging lens
Object Distance           - real object                     - real object
+ virtual object                 + virtual object

Image Distance           - real image                          + real image
+ virtual image                   - virtual image
Magnification            + for erect image                 + for erect image
- for inverted image            - for inverted image

when two plane mirror inclined to each other at an angle 60degree , the number of image =?

please explain with ray diagram .

Asked By: ASHOK SOLANKI
Joshi sir comment

angle is 60

if object is placed symmetrical then images = 360/60 - 1 = 5

if unsymmetrical then 360/60 = 6

what is defination of polarization

Joshi sir comment

Polarisation is the phenomenon to turn light in a particular direction by any means

for an aperture of size a illuminated by a parallel beam of light having wavelength λ the fresnel distance is

ans a^2/λ       what is fresnel dist.??

Asked By: SARIKA SHARMA
is this question helpfull: 2 0 read solutions ( 1 ) | submit your answer
Joshi sir comment

fringe width β = λD/d

for β = d , D is called fresnel distance

so d2 = λD

so D = d2/ λ

now change d by a

which physical quantity has its unit as LUX??

Asked By: SARIKA SHARMA
Joshi sir comment

its illuminance

Physics >> Optics >> Refraction Medical Exam

if ω1 &ω2 are dispersive powers of lenses of focal length f1 & f2 respectively . then the condition of chromatic aberration for two lenses in contact is

1) ω1/ω2 = f2/f1

2) ω1/ω2 = f1/f2

3) ω1/ω2= - f1/f2

4) ω2/ω1= f1/f2