An air doubble is inside water (μ=\(\frac{4}{3}\)). At what distance from the air bubble should a point object be placed so as to form a real image at the same distance from the dubble? (r is the radius of curvature of the bubble)
2R
4R
3R
The air bubble cannot form a real image
The Correct Option is D
Solution and Explanation
Top Questions on Ray optics and optical instruments
- A thin prism \( P_1 \) with angle \( 4^\circ \) made of glass having refractive index 1.54 is combined with another thin prism \( P_2 \) made of glass having refractive index 1.72 to get dispersion without deviation. The angle of the prism \( P_2 \) in degrees is:
- JEE Main - 2025
- Physics
- Ray optics and optical instruments
- A hemispherical vessel is completely filled with a liquid of refractive index \( \mu \). A small coin is kept at the lowest point \( O \) of the vessel as shown in the figure. The minimum value of the refractive index of the liquid so that a person can see the coin from point \( E \) (at the level of the vessel) is:
- JEE Main - 2025
- Physics
- Ray optics and optical instruments
Given below are two statements. One is labelled as Assertion (A) and the other is labelled as Reason (R):
Assertion (A): An electron in a certain region of uniform magnetic field is moving with constant velocity in a straight line path.
Reason (R): The magnetic field in that region is along the direction of velocity of the electron.In the light of the above statements, choose the correct answer from the options given below:
- JEE Main - 2025
- Physics
- Ray optics and optical instruments
- A long straight wire of a circular cross-section with radius \( a \) carries a steady current \( I \). The current is uniformly distributed across this cross-section. The plot of magnitude of magnetic field \( B \) with distance \( r \) from the centre of the wire is given by:
- JEE Main - 2025
- Physics
- Ray optics and optical instruments
- The focal length of a concave mirror in air is \( f \). When the mirror is immersed in a liquid of refractive index \( \frac{3}{5} \), its focal length will become:
- CBSE CLASS XII - 2025
- Physics
- Ray optics and optical instruments
Questions Asked in BCECE exam
- Instantaneous displacement current of 1.0A in the space between the parallel plates of 1μF capacitor can be established by changing the potential difference of:
- BCECE - 2023
- Electromagnetic waves
- What is the r.m.s value of an alternating current which when passed through a resistor produces heat, which is four times that produced by a current of 2A in the same resistor?
- BCECE - 2023
- Alternating current
- An r.m.s voltage of 220 V is applied across a series circuit having a resistance of 100 ohm and an impedance of 22 ohm. the power consumed is:
- BCECE - 2023
- Alternating current
- The resolving power of a telescope is directly proportional to:
- BCECE - 2022
- Wave optics
If the length of a filament of a heater is reduced by 10% , the power of the heater will:
- BCECE - 2022
- Refraction of Light
Concepts Used:
Spherical Mirrors
A spherical mirror is a mirror which has been cut out of a spherical surface.
There are two kinds of spherical mirrors:
- Convex Mirror
- Concave Mirror
Concave Mirror
Concave mirrors are also called converging mirrors, because in these types of mirrors, light rays converge at a point after impact and reflect back from the reflective surface of the mirror.
Convex Mirror
The convex mirror has a reflective surface that is curved outward. Regardless of the distance between the subject and the mirrors, these mirrors are "always" virtual, upright and reduced.