Geometrical Optics

A pole is vertically submerged in swimming pool, such that it gives a length of shadow \(2.15 \mathrm{~m}\) within water when sunlight is incident at angle of \(30^{\circ}\) with the surface of water. If swimming pool is filled to a height ...

A monochromatic light wave with wavelength \(\lambda_{1}\) and frequency \(v_{1}\) in air enters another medium. If the angle of incidence and angle of refraction at the interface are \(45^{\circ}\) and \(30^{\circ}\) respectively, then the...

A 2 meter long scale with least count of \(0.2 \mathrm{~cm}\) is used to measure the locations of objects on an optical bench. While measuring the focal length of a convex lens, the object pin and the convex lens are placed at $$80 \mathrm{...

Given below are two statements: one is labelled as Assertion A and the other is labelled as Reason R
Assertion A: The phase difference of two light waves change if they travel through different media having same thickness, but different ind...

A microscope is focused on an object at the bottom of a bucket. If liquid with refractive index $\frac{5}{3}$

is poured inside the bucket, then the microscope has to be raised by $30 \mathrm{~cm}$ to focus the object again.

The height of ...

In an experiment for estimating the value of focal length of converging mirror, image of an object placed at \(40 \mathrm{~cm}\) from the pole of the mirror is formed at distance \(120 \mathrm{~cm}\) from the pole of the mirror. These dista...

A person has been using spectacles of power \(-1.0\) dioptre for distant vision and a separate reading glass of power \(2.0\) dioptres. What is the least distance of distinct vision for this person :

A thin prism $P_1$ with an angle $6^{\circ}$ and made of glass of refractive index $1.54$ is combined with another prism $P_2$ made from glass of refractive index $1.72$ to produce dispersion without average deviation. The angle of prism $P...

In an experiment of measuring the refractive index of a glass slab using travelling microscope in physics lab, a student measures real thickness of the glass slab as 5.25 mm and apparent thickness of the glass slab as 5.00 mm. Travelling mi...

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)

A ray of light is incident from air on a glass plate having thickness \(\sqrt3\) cm and refractive index \(\sqrt2\). The angle of incidence of a ray is equal to the critical angle for glass-air interface. The lateral displacement of the ray...

An object is placed on the principal axis of convex lens of focal length 10cm as shown. A plane mirror is placed on the other side of lens at a distance of 20 cm. The image produced by the plane mirror is 5cm inside the mirror. The distance...

The light rays from an object have been reflected towards an observer from a standard flat mirror, the image observed by the observer are :-
A. Real
B. Erect
C. Smaller in size then object
D. Laterally inverted
Choose the most appropriate a...

As shown in the figure, a combination of a thin plano concave lens and a thin plano convex lens is used to image an object placed at infinity. The radius of curvature of both the lenses is 30 cm and refraction index of the material for both...

A convex lens of refractive index 1.5 and focal length 18cm in air is immersed in water. The change in focal length of the lens will be ___________ cm.
(Given refractive index of water \(=\frac{4}{3}\))

When a beam of white light is allowed to pass through convex lens parallel to principal axis, the different colours of light converge at different point on the principle axis after refraction. This is called :

A thin cylindrical rod of length \(10 \mathrm{~cm}\) is placed horizontally on the principle axis of a concave mirror of focal length \(20 \mathrm{~cm}\). The rod is placed in a such a way that mid point of the rod is at \(40 \mathrm{~cm}\)...

Two objects A and B are placed at 15 cm and 25 cm from the pole in front of a concave mirror having radius of curvature 40 cm. The distance between images formed by the mirror is _______________.

The refractive index of a transparent liquid filled in an equilateral hollow prism is $\sqrt{2}$. The angle of minimum deviation for the liquid will be ___________ \(^\circ\).

A fish rising vertically upward with a uniform velocity of \(8 \mathrm{~ms}^{-1}\), observes that a bird is diving vertically downward towards the fish with the velocity of \(12 \mathrm{~ms}^{-1}\). If the refractive index of water is $$\fr...

A vessel of depth '\(d\)' is half filled with oil of refractive index \(n_{1}\) and the other half is filled with water of refractive index \(n_{2}\). The apparent depth of this vessel when viewed from above will be-

A bi convex lens of focal length \(10 \mathrm{~cm}\) is cut in two identical parts along a plane perpendicular to the principal axis. The power of each lens after cut is ____________ D.

Two convex lenses of focal length \(20 \mathrm{~cm}\) each are placed coaxially with a separation of \(60 \mathrm{~cm}\) between them. The image of the distant object formed by the combination is at _____________ \(\mathrm{cm}\) from the fi...

An ice cube has a bubble inside. When viewed from one side the apparent distance of the bubble is \(12 \mathrm{~cm}\). When viewed from the opposite side, the apparent distance of the bubble is observed as \(4 \mathrm{~cm}\). If the side of...

The radius of curvature of each surface of a convex lens having refractive index 1.8 is \(20 \mathrm{~cm}\). The lens is now immersed in a liquid of refractive index 1.5 . The ratio of power of lens in air to its power in the liquid will be...

The critical angle for a denser-rarer interface is \(45^{\circ}\). The speed of light in rarer medium is \(3 \times 10^{8} \mathrm{~m} / \mathrm{s}\). The speed of light in the denser medium is:

As shown in the figure, a plane mirror is fixed at a height of \(50 \mathrm{~cm}\) from the bottom of tank containing water \(\left(\mu=\frac{4}{3}\right)\). The height of water in the tank is \(8 \mathrm{~cm}\). A small bulb is placed at t...

When one light ray is reflected from a plane mirror with \(30^{\circ}\) angle of reflection, the angle of deviation of the ray after reflection is :

An object is placed at a distance of 12 cm in front of a plane mirror. The virtual and erect image is formed by the mirror. Now the mirror is moved by 4 cm towards the stationary object. The distance by which the position of image would be ...

A point object, 'O' is placed in front of two thin symmetrical coaxial convex lenses \(\mathrm{L}_{1}\) and \(\mathrm{L}_{2}\) with focal length \(24 \mathrm{~cm}\) and \(9 \mathrm{~cm}\) respectively. The distance between two lenses is $$1...

The refractive index of an equilateral prism is \(\sqrt 2\). The angle of emergence under minimum deviation position of prism, in degree, is ___________.

A parallel beam of light is allowed to fall on a transparent spherical globe of diameter 30 cm and refractive index 1.5. The distance from the centre of the globe at which the beam of light can converge is _____________ mm.

The speed of light in media 'A' and 'B' are \(2.0 \times {10^{10}}\) cm/s and \(1.5 \times {10^{10}}\) cm/s respectively. A ray of light enters from the medium B to A at an incident angle '\(\theta\)'. If the ray suffers total internal refl...

The X-Y plane be taken as the boundary between two transparent media \(\mathrm{M}_{1}\) and \(\mathrm{M}_{2}\). \(\mathrm{M}_{1}\) in \(Z \geqslant 0\) has a refractive index of \(\sqrt{2}\) and \(M_{2}\) with \(Z<0\) has a refractive index...

Light enters from air into a given medium at an angle of \(45^{\circ}\) with interface of the air-medium surface. After refraction, the light ray is deviated through an angle of
\(15^{\circ}\) from its original direction. The refractive in...

The aperture of the objective is 24.4 cm. The resolving power of this telescope, if a light of wavelength 2440 \(\mathop A\limits^o\) is used to see th object will be :

The refracting angle of a prism is A and refractive index of the material of the prism is cot (A/2). Then the angle of minimum deviation will be -

In normal adujstment, for a refracting telescope, the distance between objective and eye piece is \(30 \mathrm{~cm}\). The focal length of the objective, when the angular magnification of the telescope is 2 , will be :

As shown in the figure, after passing through the medium 1 . The speed of light \(v_{2}\) in medium 2 will be :
\(\left(\right.\) Given \(\mathrm{c}=3 \times 10^{8} \mathrm{~ms}^{-1}\) )

In an experiment with a convex lens, The plot of the image distance \(\left(v^{\prime}\right)\) against the object distance (\(\left.\mu^{\prime}\right)\) measured from the focus gives a curve \(v^{\prime} \mu^{\prime}=225\). If all the dis...

An object 'O' is placed at a distance of \(100 \mathrm{~cm}\) in front of a concave mirror of radius of curvature \(200 \mathrm{~cm}\) as shown in the figure. The object starts moving towards the mirror at a speed $$2 \mathrm{~cm} / \mathrm...

The power of a lens (biconvex) is \(1.25 \mathrm{~m}^{-1}\) in particular medium. Refractive index of the lens is 1.5 and radii of curvature are \(20 \mathrm{~cm}\) and \(40 \mathrm{~cm}\) respectively. The refractive index of surrounding m...

Consider a light ray travelling in air is incident into a medium of refractive index \(\sqrt{2n}\). The incident angle is twice that of refracting angle. Then, the angle of incidence will be :

A convex lens has power P. It is cut into two halves along its principal axis. Further one piece (out of the two halves) is cut into two halves perpendicular to the principal axis (as shown in figures). Choose the incorrect option for the r...

A microscope was initially placed in air (refractive index 1). It is then immersed in oil (refractive index 2). For a light whose wavelength in air is \(\lambda\), calculate the change of microscope's resolving power due to oil and choose t...

A thin prism of angle \(6^{\circ}\) and refractive index for yellow light \(\left(\mathrm{n}_{\mathrm{Y}}\right) 1.5\) is combined with another prism of angle \(5^{\circ}\) and \(\mathrm{n}_{\mathrm{Y}}=1.55\). The combination produces no d...

A light ray is incident, at an incident angle \(\theta\)1, on the system of tow plane mirrors M1 and M2 having an inclination angle 75\(^\circ\) between them (as shown in figure). After reflecting from mirror M1 it gets reflected back by th...

A small bulb is placed at the bottom of a tank containing water to a depth of \(\sqrt7\) m. The refractive index of water is \({4 \over 3}\). The area of the surface of water through which light from the bulb can emerge out is x\(\pi\) m2. ...

The graph between \(\frac{1}{u}\) and \(\frac{1}{v}\) for a thin convex lens in order to determine its focal length is plotted as shown in the figure. The refractive index of lens is \(1.5\) and its both the surfaces have same radius of cur...

In the given figure, the face \(A C\) of the equilateral prism is immersed in a liquid of refractive index '\(n\)'. For incident angle \(60^{\circ}\) at the side \(A C\), the refractive light beam just grazes along face \(A C\). The refract...