The image produced is magnified and real.
Answer:

Explanation:
Given that

From the diagram

By differentiating with time t

When x= 10 m

θ = 64.53°
Now by putting the value in equation



Therefore rate of change in the angle is 0.038\ rad/s
Answer:
Sound waves are longitudinal in nature.
Explanation:
There are many types of waves like transverse, longitudinal, electromagnetic wave etc.
Sound waves are longitudinal in nature. In longitudinal type of wave, the medium particles moves parallel to the propagation of the wave. This type of waves move in the form of compression and rarefaction.
In compression, the particle density at a point is very less while in rarefaction, the particle density at a point is very high.
So, the correct option is (b) "longitudinal wave".
Answer:
1.97 x 10^8 m/s
Explanation:
refractive index of crown glass with respect to air, n = 1.52
speed of light in air, c = 3 x 10^8 m/s
Let v be the speed of light in crown glass.
By use of the definition of refractive index

where, n be the refractive index of crown glass, c be the speed of light in vacuum and v be the speed of light in crown glass


v = 1.97 x 10^8 m/s
Thus, the speed of light in crown glass is 1.97 x 10^8 m/s.