List of top Physics Questions on Optical Instruments

The unit of power of a lens is

The distance between the objective and eyepiece of an astronomical telescope in normal adjustment is $27\text{ cm}$ and its magnifying power is $8$. What is the focal length of the eyepiece?

In a microscope of tube length $10\,\text{cm}$ two convex lenses are arranged with focal lengths $2\,\text{cm}$ and $5\,\text{cm}$. Total magnification obtained with this system for normal adjustment is $(5)^k$. The value of $k$ is ___.

The magnifying power of a simple microscope can be increased by using

There is a compound microscope of lenses having focal lengths 2 cm and 5 cm and tube length 10 cm. Find magnifying power in normal adjustment. If your answer is $5^\alpha$, find '$\alpha$' :

A microscope has an objective of focal length \(f_o = 2\) cm and an eyepiece of focal length \(f_e = 4\) cm. The tube length of the microscope is \(L = 40\) cm. If the distance of distinct vision of eye is \(D = 25\) cm, the magnification in the microscope is:

Resolving power of a telescope can be increased by increasing

The length of the compound microscope is $15\text{ cm}$ . The magnifying power for relaxed eye is 25 . If the focal length of eye lens is $6\text{ cm}$ then the object distance for objective lens will be}

Resolving power of a telescope can be increased by increasing

The simple microscope having a lens of focal length 5 cm gives the magnification of (least distance of distinct vision \(= 25\) cm)

In the normal adjustment of an astronomical telescope, the objective and eyepiece are 36 cm apart. If the magnifying power of the telescope is 8, find the focal lengths of the objective and eyepiece.

The focal lengths of the objective and eyepiece of a compound microscope are \( 1 \, \text{cm} \) and \( 10 \, \text{cm} \) respectively. Length of the tube is \( 25 \, \text{cm} \). If the final image is formed at infinity, the magnifying power of the microscope is:

Resolving power of a telescope can be increased by increasing

The clarity of the image formed on the retina of the eye depends on the ____

The intermediate image formed by an objective lens of a compound microscope is

In normal adjustment, for a refracting telescope, the distance between the objective and eyepiece lens is 1.00 m. If the magnifying power of the telescope is 19, find the focal length of the objective and the eyepiece lens.

Two different lenses are used in telescope because

A scientist is observing a bacteria through a compound microscope. For better analysis and to improve its resolving power he should. (Select the best option)

Only 2% of the optical source frequency is the available channel bandwidth for an optical communicating system operating at 1000 nm. If an audio signal requires a bandwidth of 8 kHz, how many channels can be accommodated for transmission?

A man who wears glasses of power \(3D\) must hold a newspaper at least \(25\,cm\) away to see clearly. How far away would the newspaper have to be if he took off the glasses and still wanted clear vision?

The magnifying power of a telescope is \(m\). If the focal length of the eye piece is doubled, then its magnifying power becomes:

A man at a distance \(11\,km\) from two pillars wants to see them separately. What will be the approximate distance between the pillars?

When an object is viewed with a light of wavelength \( 6000 \,\text{\AA} \) under a microscope its resolving power is \( 10^4 \). The resolving power of the microscope when the same object is viewed with a light of wavelength \( 4000 \,\text{\AA} \) is