Question:
While viewing a distant object with a telescope suddenly a housefly sits on objective lens. The correct statement is that
While viewing a distant object with a telescope suddenly a housefly sits on objective lens. The correct statement is that
Show Hint
Any obstruction on the objective lens of a telescope will decrease the intensity of the image and may distort the view.
Updated On: Apr 22, 2026
- housefly will be seen enlarged in image
- housefly will be seen reduced in image
- intensity of image will be decreased
- intensity of image will be increased
Show Solution
Verified By Collegedunia
The Correct Option is C
Solution and Explanation
Step 1: Understanding the effect of an object on the telescope's image.
A telescope works by using two lenses: the objective lens (which gathers light) and the eyepiece lens (which magnifies the image). The object, when it sits on the objective lens, interferes with the light path and the image formed.
Step 2: Effect of the housefly on the image.
- The housefly is an opaque object that will block some of the light entering the objective lens. This will result in a reduction in the intensity of the image formed because less light will reach the eyepiece.
- Additionally, the housefly will cause some distortion and may reduce the clarity of the image as well.
Step 3: Conclusion.
The correct answer is (3), as the intensity of the image will be decreased due to the obstruction caused by the housefly.
A telescope works by using two lenses: the objective lens (which gathers light) and the eyepiece lens (which magnifies the image). The object, when it sits on the objective lens, interferes with the light path and the image formed.
Step 2: Effect of the housefly on the image.
- The housefly is an opaque object that will block some of the light entering the objective lens. This will result in a reduction in the intensity of the image formed because less light will reach the eyepiece.
- Additionally, the housefly will cause some distortion and may reduce the clarity of the image as well.
Step 3: Conclusion.
The correct answer is (3), as the intensity of the image will be decreased due to the obstruction caused by the housefly.
Was this answer helpful?
0
0
Top MET Physics Questions
- A coil of 100 turns and area $2 \times 10^{-2}m^2 $ is pivoted about a vertical diameter in a uniform magnetic field and carries a current of 5A. When the coil is held with its plane in north-south direction, it experiences a couple of 0.33 Nm. When the plane is east-west, the corresponding couple is 0.4 Nm, the value of magnetic induction is [Neglect earth's magnetic field]
- Radiation, with wavelength 6561 $?$ falls on a metal surface to produce photoelectrons. The electrons are made to enter a uniform magnetic field of $3 \times 10^{-4} T$. If the radius of the largest circular path followed by the electrons is 10 mm, the work function of the metal is close to :
- In intrinsic semiconductor at room temperature number of electrons and holes are
- A rope of mass $0.1\, kg$ is connected at the same height of two opposite walls. It is allowed to hang under its own weight. At [he contact point between the rope and the wall, the rope makes an angle $ \theta =10^{\circ} $ with respect to horizontal. The tension in the rope at its midpoint between the walls is
- At great distances from an electric dipole, the electric field strength due to the dipole varies with the distance as
View More Questions
Top MET Optical Instruments Questions
- The magnifying power of a telescope is 9. When it is adjusted for parallel rays, the distance between the objective and eye-piece is 20 cm. The focal length of objective and eye-piece are:
- 0.5 mole of each of $H_{2}$, $SO_{2}$ and $CH_{4}$ are kept in a container. A hole was made in the container. After 3 h, the order of partial pressures in the container will be
- A man at a distance \(11\,km\) from two pillars wants to see them separately. What will be the approximate distance between the pillars?
- 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 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?
View More Questions
Top MET Questions
- A coil of 100 turns and area $2 \times 10^{-2}m^2 $ is pivoted about a vertical diameter in a uniform magnetic field and carries a current of 5A. When the coil is held with its plane in north-south direction, it experiences a couple of 0.33 Nm. When the plane is east-west, the corresponding couple is 0.4 Nm, the value of magnetic induction is [Neglect earth's magnetic field]
- $\int\limits_{0}^{8}| x -5| d x$ is equal to
- Radiation, with wavelength 6561 $?$ falls on a metal surface to produce photoelectrons. The electrons are made to enter a uniform magnetic field of $3 \times 10^{-4} T$. If the radius of the largest circular path followed by the electrons is 10 mm, the work function of the metal is close to :
- In intrinsic semiconductor at room temperature number of electrons and holes are
- Which of the following product is formed in the reaction $ CH_3MgBr {->[(i)CO_2][(ii)H_2O]} ? $
View More Questions