Download App

Ray Optics and Optical Instruments — Physics STD 12 Science — Question

Gujarat BoardEnglish MediumSTD 12 SciencePhysicsRay Optics and Optical Instruments3 Marks
Question
Define the term 'resolving power' of an astronomical telescope. How does it get affected on?
  1. Increasing the aperture of the objective lens?
  2. Increasing the wavelength of the light used?
Justify your answer in each case.
✓

Answer

Resolving power (R.P) is the reciprocal of limit of angular resolution OR any other suitable definition.
  1. Increases:
Resolving power $ = \frac{\text{d}}{1.22\lambda}$

$\therefore$ R.P is directly proportional to ‘d’ (For a given $\lambda$)
  1. Decreases:
$\therefore$ R.P is inversely proportional to $'\lambda'$ (For a given d).

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free

Explore more

More "3 Marks Question" from Ray Optics and Optical Instruments→Ray Optics and Optical Instruments — all question types→Physics STD 12 Science question papers→Gujarat Board STD 12 Science question papers→Gujarat Board question paper generator→

Similar questions

Two prisms of identical geometrical shape are combined with their refracting angles oppositely directed. The materials of the prisms have refractive indices 1.52 and 1.62 for violet light. A violet ray is deviated by 1.0° when passes symmetrically through this combination. What is the angle of the prisms?
→
Whenever a photon is emitted by hydrogen in Balmer series, it is followed by another photon in Lyman series. What wavelength does this latter photon correspond to?
→
  1. Name two important processes that occur during the formation of a pn junction.
  2. Draw the circuit diagram of a full wave rectifier along with the input and output waveforms. Briefly, explain how the output voltage/current is unidirectional.
→
Suppose the spheres A and B in Exercise 1.12 have identical sizes. A third sphere of the same size but uncharged is brought in contact with the first, then brought in contact with the second, and finally removed from both. What is the new force of repulsion between A and B?
→
→
A long charged cylinder of linear charge density $+\lambda_1$ is surrounded by a hollow coaxial conducting cylinder of linear charge density $-\lambda_2$. Use Gauss’s law to obtain expressions for the electric field at a point (i) in the space between the cylinders, and (ii) outside the larger cylinder.
→
A simple pendulum consists of a 50cm long string connected to a 100g ball. The ball is pulled aside so that the string makes an angle of 37° with the vertical and is then released. Find the tension in the string when the bob is at its lowest position.
→
Derive the equation for the torque acting on current-carrying coil place in uniform magnetic ficld $\overrightarrow{ B }$.
→
Figure shows the x coordinate of a particle as a function of time. Find the signs of $v_x$ and $a_x$ at $t = t_1, t = t_2$ and $t = t_3.$
→
Two sources of sound, $S_1$ and $S_2,$ emitting waves of equal wavelength 20.0cm, are placed with a separation of 20.0cm between them. A detector can be moved on a line parallel to $S_1S_2,$ and at a distance of 20.0cm from it. Initially, the detector is equidistant from the two sources. Assuming that the waves emitted by the sources are in phase, find the minimum distance through which the detector should be shifted to detect a minimum of sound.
→