Answer:
24.71 mm
Explanation:
Distance is proportional to focal length, so
d∝f
which means

Magnification of first lens

and

Similarly, magnification of second lens

and

From the above equations we get

and

which means,

and

So, we get

∴ Focal length should this camera's lens is 24.71 mm
As we know by Doppler's effect of light we have

here we will have
[tex}\frac{398.1 nm - 396.9 nm}{398.1 nm} = \frac{v}{c}[/tex]
here by solving above we have

here we have

since wavelength is increased so we can say that it is moving away
so correct answer is
1- 904.3 km/s away from the Earth
Answer:
a) 600nm
b) 300nm
Explanation:
the path difference = 2t
t = thickness of the film
L' = wavelength of light in film = L/n
L = wavength of light in air
n = refractive index of glass
(a)
for destructive interference 2t = L'/2 = L/2n
L = 4*t*n
= 4*120*10^-9*1.25
L = 600 nm
(b)
for constructive interference 2t = L' = L/1.25
L = 2tn
= 2 × 1.25 × 120nm
= 300 nm
Answer:

Explanation:
As we know that base of the slab is given as


now we know that rate of heat transfer is given as

here we know that

Also we have


