InterviewSolution
Saved Bookmarks
InterviewSolution
This section includes InterviewSolutions, each offering curated multiple-choice questions to sharpen your knowledge and support exam preparation. Choose a topic below to get started.
| 101. |
A convex lens of focal length `10 cm` is placed co-axially `5 cm` away from a concave lens of focal length `10 cm`. If an object is placed `30 cm` in front of the convex lens, find the position of final image formed by the combined system. |
|
Answer» For the convex lens, `f = 10 cm, u = -30 cm` `(1)/(v)=(1)/(f)+(1)/(u)=(1)/(10)-(1)/(30)=(1)/(15), v = 15 cm`. As concave lens is at `5 cm` from convex lens, therefore image formed by convex lens is at `(15 - 5)cm = 10 cm` beyond concave lens. For concave lens `u = + 10 cm, f = -10 cm` `(1)/(v)=(1)/(f)+(1)/(u)=-(1)/(10)+(1)/(10)=0` `:. v = oo` i.e., final image is formed at infinity. |
|
| 102. |
A biconvex lens has focal length `(2)/(3)` times the radius of curvature of either surface. Calculate refraction index f material of the lens. |
|
Answer» Correct Answer - `1.75` Here, `f = (2)/(3)`, where `R_1 = R, R_2 = -R = -R, mu = ?` From `(1)/(f) = (mu - 1)((1)/(R_1) - (1)/(R_2))` `(3)/(2 R) = (mu - 1) ((1)/( R) + (1)/( R)) = (mu - 1) (2)/( R)` `mu - 1 = (3)/(4) = 0.75, mu = 1.75`. |
|
| 103. |
A spherial light bulb with a diameter of`3.0cm` radiateds equally in all the directions with a power of `4.5piW.`(a find the light intensity of the surface of the bulb.(b) Find the light set up with its axis pointing towards the bulb.The lens has a circular face witb a diameter of `15.0cm`and a focal length of `30.0cm`Find the diamerter of the image of the bulb formed on a screen kept at the location of hte image .(d)Find the light intensity at the image. |
|
Answer» Correct Answer - `(a)5000w//m^(2) (b)0.02W//m^(2)` ©0.125cm(d)`288W//m^(2)` (a)`I=(P)/(4piR^(2))` `I=(4.5pi)/(4pi(1.5xx10^(-2))^(2))rArr I=(4.5xx10^(4))/(4xx2.25)"watt"//m^(2)` `I=5000"watt"//m^(2)` (b) `I_(1)=(P)/(4pir^(2)) rArr I_(1)=(4.5pi)/(4pi(15//2)^(2))` `I_(1)=(4.5xx10^(4))/(4pixx(225)/(4)) "Watt"//m^(2) rArr I_(1)=(4.5)/(225)"Watt"//m^(2)` `I_(1)=0.02"Watt"//m^(2)` (c) `(h_(I))/(h^(@))=(v)/(u)=(f)/(f+u) rArr` since `h_(@)=d//2=1.5cm` hence`(h_(1))/(1.5)=(30)/(30+(-750)) rArr h_(1) =-(1)/(16)` diameter of the image=`2h_(1)` diameter of the image=`2xx(1)/(16)cm rArr` diameter of the image=`0.125cm` Light intensity at image`I_(2)=("energy received by the lens per second")/("area of image")` energy received per second=intensity at lens x area of lens `I_(1)xxpi(d_("lens")//2)^(2)` area of image=`pi(d_("image")//2)^(2)` `I_(2)=(I_(1)xxpi(d_("lens")//2)^(2))/(pi(d_("image")//2)^(2))rArr I_(2)=I_(1)xx(d_(("lens"))/(d_("image")^(2)))^(2) rArr I_(2)=0.02xx((15)/(0.125))^(2)` `=0.02xx(120)^(2)` `I_(2)=288 "Watt"//m^(2)` |
|
| 104. |
A plastic hemisphere has a radius of curvature of 8 cm and an index of refraction of 1.6. ON the axis halfway between the plane surface and the spherical one (4 cm from each) is a small object O. The distance between the two images when viewed along the axis from the two sides of the hemisphere is approximately A. `1.0 cm`B. `1.5 cm`C. `3.75 cm`D. `2.5 cm` |
| Answer» Correct Answer - D | |
| 105. |
The focal length of an equiconvex lens is equal to radius of curvature of either surface. What is the refractive index of the material of the prism ? |
|
Answer» Here, `R_1 = R, R_2 = -R , f = , mu = ?` From `(1)/(f)=(mu -1)((1)/(R_1) - (1)/(R_2))` `(1)/(R ) = (mu - 1) ((1)/( R) + (1)/( R)) = (mu - 1)(2)/( R)` `mu - 1 = (1)/(2)` or `mu = 3//2 = 1.5`. |
|
| 106. |
An object of height 1.5 cm is placed on the axis of a convex lens of focal length 25 cm . A real image is formed at a distance of 75 cm from the lens. The size of the image will beA. 4.5 cmB. 3.0 cmC. 0.75 cmD. 0.5 cm |
| Answer» Correct Answer - b | |
| 107. |
A thin equiconvex lens of glass of refractive index `mu=3//2` & of focal length `0.3m`in air is sealed into an opeing at one end of a tank filled with water `(mu=4//3)` .Ont he oppostie side of the lens ,a mirror is placed inside the tank on the tank wall perpendicualar tot he lens axis ,as shown in figure .the seperation bertween the lens and the mirror is `0.8m`A small object is placed outside the tank in front of the lens at a distance of `0.9`m form the lens along its axis .Find the position (relative to the lens)of the image of the object fromed byt he stsyem. |
|
Answer» Correct Answer - `90cm`from the lens towards right For radius of curvature `(1)/(f)=(._(a)mu_(g)-1)((1)/(R_(1))-(1)/(R_(2))) rArr (1)/(f)=(._(a)mu_(g)-1)((1)/(R )-(1)/(-R)) rArr (1)/(30)=((3)/(2)-1)xx(2)/(R )` `R=30cm` taking refraction from first curved surface `(mu_(2))/(v)-(mu_(1))/(u)=(mu_(2)-mu_(1))/(R )rArr (3)/(2v)-(1)/(-90)=(3//2-1)/(30) rArr(3)/(2v)=(1)/(60)-(1)/(90)` `(3)/(2v)=(3-2)/(180) rArr v= 270cm` this image will act as object for second surface.`(4)/(3v)-(3)/(2xx270)=(4//3-3//2)/-(30)rArr v=120cm` this image will act a object for mirror ,u for mirror=`(120-80)=40cm` this image will formed by mirror infornt ata distance of `40cm`.This image wil act as object for curved surface of lens. `u=-(80-40)cm rArr u=-40cm rArr(3)/(2v)-(4)/(3xx(-40))=(3//2-4//3)/(30)` `(3)/(2v)+(1)/(30)=(1)/(180)rArr (1)/(180)-(1)/(30) rArr (3)/(2v)=(1-6)/(180) rArr (3)/(2v)=(-5)/(180)` `(3)/(2v)=(1)/(-36)rArr v=-54cm` This image will act as object for second refraction. `(1)/(v)-(3)/(2(-54))=(1-3//2)/(-30) rArr (1)/(v)+(1)/(36)=(1)/(60)rArr (1)/(v)=(1)/(60)-(1)/(36)` `(1)/(v)=(3-5)/(180)rArr v=(180)/(-2)` `v=-90cm` So image wil formed at `90cm`towards right of lens. |
|
| 108. |
An equiconvex lens of glass of focal length `0.1 ` metre is cut along a plane perpendicular to principle axis into two equal parts. The ratio of focal length of new lenses formes isA. `1 : 1`B. `1 : 2`C. `2 : 1`D. `2 : 1/2` |
| Answer» Correct Answer - a | |
| 109. |
A ray of light falls on a transparent sphere with centre at C as shown in figure. The ray emerges from the sphere parallel to line AB. The refractive index of the sphere is A. `sqrt(2)`B. `sqrt(3)`C. `3//2`D. `4//3` |
| Answer» Correct Answer - B | |
| 110. |
A hollow double concave lens is made of very thin transparent material. It can be filled with air or either of two liquids `L_(1)` or `L_(2)` having refractive indices `n_(1)` and `n_(2)`, respectively `(n_(2) gt n_(1) gt 1)`. The lens will diverge parallel beam of light if it is filles withA. Air and placed in airB. Air and immersed in `L_(1)`C. `L_(1)` and immersed in `L_(2)`D. `L_(1)` and immersed in `L_(2)` |
| Answer» Correct Answer - D | |
| 111. |
A poinit object `O` is placed in front of a glass rod having spherical end of radius of curvature `30cm`. The image would be formed at A. `30 cm` leftB. InfinityC. 1 cm to the rightD. 18 cm to the left |
| Answer» Correct Answer - a | |
| 112. |
Calculate the focal length of a reading glass of a person, if the distance of distinct vision is 75cm.A. 75.2 cmB. 25.6 cmC. 100.4 cmD. 37.5 cm |
|
Answer» Correct Answer - D Given, `v=-75 cm` `u=-25 cm` We know that, lens formula, we have `(1)/(f)=(1)/(v)-(1)/(u)` `(1)/(f)=(-1)/(75)+(1)/(25)` `(1)/(f)=(1)/(25)-(1)/(75)` `(1)/(f)=(3-1)/(75)` `(1)/(f)=(2)/(75)` Focal length of a glass, `f=(75)/(2)=37.5 cm` |
|
| 113. |
A person wants a real image of his own, 3 times enlarged. Where should he stand in front of a concave mirror of radius of curvature of 30cm.A. 90cmB. 10cmC. 20cmD. 30cm |
|
Answer» Correct Answer - C Given, ,=-3, and R=30cm `f=(R )/(2)=-15cm` We know that `m=-(v)/(u) Rightarrow -3=(-v)/(u)` v=3u `"Also" (1)/(f)=(1)/(v)+(1)/(u) ` `(1)/(-15)=(1)/(3u)+(1)/(u)Rightarrow (-1)/(15)=(1+3)/(3u)` `-3u=4xx15` `Rightarrow u=(-4xx15)/(3)` Initial position of a person, u=-20cm |
|
| 114. |
A person wants a real image of his own, 3 times enlarged. Where should he stand in front of a concave mirror of radius of curvature of 30cm.A. 90 cmB. 10 cmC. 20 cmD. 30 cm |
|
Answer» Correct Answer - C Given, `m=-3` and R = 30 cm `f=-(R )/(2)=-15 cm` We know that, `m=-(v)/(u) rArr -3 =(-v)/(u)` `v=3 u` Also, `(1)/(f)=(1)/(v)+(1)/(u)` `(1)/(-15)=(1)/(3u)+(1)/(u)rArr (-1)/(15)=(1+3)/(3u)` `-3u=4xx15` `rArr " " u=(-4xx15)/(3)` Initial positive of a person, `u = -20 cm` |
|
| 115. |
A convex lens of focal length 30 cm forms an image of height 2 cm for an object situated at infinity. If a concave lens of focal length 20 cm is placed coaxially at a distance of 26 cm from convex lens then size of image would beA. `2.5 cm`B. `5.0 cm`C. `1.25 cm`D. `4 cm` |
| Answer» Correct Answer - A | |
| 116. |
The size of the image of an object, which is at infinity, as formed by a convex lens of focal length 30 cm is 2 cm. If a concave lens of focal length 20 cm is placed between the convex lens and the image at a distance of 26 cm from the convex lens, calculate the new size of the imageA. 1.25 cmB. 2.5 cmC. 1.05 cmD. 2 cm |
| Answer» Correct Answer - B | |
| 117. |
A simple microscope consists of a concave lens of power `-10D` and convex lens of power `+20D` in contact. If the image formed at infinity, then calculate the magnifying power `(D=25cm`)A. `2.5`B. `3.5`C. `2.0`D. `3.0` |
|
Answer» (a) Power of combination `P=P_(1)+P_(2)` `P=+20-10=+10D` `F=1/P=1/10m=100/10cm=10cm` For final image at infinity `M=D/F=25/10=2.5` |
|
| 118. |
Total internal reflection will occure only when………………in………….medium is………………than…………for the pair of media in contact. |
| Answer» angle of incidence , denser , equal to or greater , critical angle. | |
| 119. |
STATEMENT-`1`The critical angle in case of total internal reflection depends on the pair of medium chosen. `STATEMENT 2`The critical angle in case of total internal reflection is independent of pair of medium chosen.A. STATEMENT -`1`is true statement `2` is true,Statement -`2`is a correct explanation for statement -`1`B. STATEMENT -`1`is true statement `2` is true,Statement -`2`is a not a correct explanation for statement -`1`C. Statement -`1`is true,Statement -`2`is FalseD. Statement -`1`is False ,Statement -`2`is True |
|
Answer» Correct Answer - C `theta_(C)=sin-1(1//mu)` and is taken relative, hence it depends on pair of medium chosen. |
|
| 120. |
Statement I: A lighr ray is incident on a glass slab. Some portion of it is reflected and some is refracted. Reeefracted and reflected rays are always perpendicular to each other. Statement II: Angle of incidence is equal to angle of reflection. A. STATEMENT -`1`is true statement `2` is true,Statement -`2`is a correct explanation for statement -`1`B. STATEMENT -`1`is true statement `2` is true,Statement -`2`is a not a correct explanation for statement -`1`C. Statement -`1`is true,Statement -`2`is FalseD. Statement -`1`is False ,Statement -`2`is True |
|
Answer» Correct Answer - D `1xx sini =sin r` `=sin(90-i)` `sin i=cos i` `rArr tan i=mu` So relected and reflected rays are perpendicular if tani=. |
|
| 121. |
A ray of light is incident on the interface between water and glass at an angle `i` and refracted parallel to the water surface, then value of `mu_(g)` will be A. `(4//3)sini`B. `1/(sin i)`C. `4/3`D. `1` |
|
Answer» (b) `._(g)mu_(w)=(sin i )/(sin r)` `._mu_(a)=(sin r)/(sin 90^(@))` `implies ._(g)mu_(w)xx._(w)mu_(a)=(sin i)/(sin r)=(sin r)/(sin 90^(@))=sini` or `(mu_(w))/(mu_(g))xx(mu_(a))/(mu_(w))=sin i impliesmu_(g)=1/(sin i)` |
|
| 122. |
On a glass plate a light wave is incident at an angle of `60^(@)`. If the reflected and the refracted waves are mutually perpendicular, the refractive index of material isA. `sqrt(3)/2`B. `sqrt(3)`C. `3/2`D. `1/sqrt(3)` |
| Answer» Correct Answer - b | |
| 123. |
When light travels from glass to air, the incident angle is `theta_(1)` and the refracted angle is `theta_(2)`. The true relation isA. `theta_(1) =theta(2)`B. `theta_(1) lt theta_(2)`C. `theta_(1) gt theta_(2)`D. Not predictable |
| Answer» Correct Answer - b | |
| 124. |
An object is immersed in a fluid. In order that the object becomes invisible, it shouldA. Behave as a perfect reflectorB. Absorb all light falling on itC. Have refractive index oneD. Have refractive index exactly matching with that of the surrounding fluid |
| Answer» Correct Answer - d | |
| 125. |
The refractive index of a material of a prism of angles `45^(@) - 45^(@) - 90^(@)` is 1.5. The path of the ray of light incident normally on the hypotenuse side is shown inA. B. C. D. |
| Answer» Correct Answer - a | |
| 126. |
A convex lens if in contact with concave lens. The magnitude of the ratio of their focal length is `(2)/(3)`. Their equivalent focal length is 30 cm. What are their individual focal lengths?A. `75,-50`B. `75,50`C. `10,-15`D. `-75,50` |
|
Answer» Correct Answer - C `P=(1)/(f)rArr (P_(1))/(P_(2))=(f_(2))/(f_(1))=-(3)/(2)` Let focal length of convex lens is `f_(1)=f`than focus length of concave length `f_(2)=-(3f)/(2)` So,`(1)/(30)=(1)/(f)-(2)/(3f)` `(1)/(30)=(3-2)/(3f)` `f=10cm` `f_(1)=10cm,f_(2)=-15cm` |
|
| 127. |
What is the minimum value of the refractive index for a `90^(@)-45^(@)-45^(@)` prism which is used to deviate a beam through `90^(@)` by total internal reflection ? A. `3//2`B. `sqrt(3)`C. `sqrt(2)`D. `5//3` |
| Answer» Correct Answer - C | |
| 128. |
A convex lens is in contact with a concave lens. The magnitude of the ratio of their powers is `(3)/(2)`. Their equivalent focal length is 30 cm. What are their individual focal lengths?A. `-75, 50`B. `-10, 15`C. `-75, 25`D. `-15, 10` |
| Answer» Correct Answer - D | |
| 129. |
A concave lens of focal length 20 cm placed in contact with a plane mirror acts as aA. convex mirror of focal length 10 cmB. concave mirror of focal length 40 cmC. concave mirror of focal length 60 cmD. concave mirror of focal length 10 cm |
|
Answer» Correct Answer - A (a) Power, `P=2P_(L)+P_(M)` or `-1/F=2(-1/0.2)+0orF= 10cm` On silvering the surface of the lens, it behaves as a mirror. Therefore, the combination behaves as a convex mirror of focal length 10 cm. |
|
| 130. |
The optical density of turpentine is higher than that of water, while its mass density is lower. Fig. shows a layer of turpentine floating over water in a container. For which one of the four rays incident on turpentine in Fig., the path shows is correct ? .A. 1B. 2C. 3D. 4 |
|
Answer» Correct Answer - B (b) Here light rays goes from (optically) rarer medium air to optically denser turpentine, then it bends towards the normal i.e., i`gt`r whereas when it goes from to optically denser medium turpentine to rarer medium water, then it bends away the normal i.e., i`gt`r. |
|
| 131. |
The resolving power of electron microscope is higher that that of an optical microscope because the wavelength of electrons is ……. Than the wavelength of visible light.A. If both assertion and reason are true and the reason is the correct explanation of the assertionB. If both assertion and reason are true but reason is not the correct explanation of the assertionC. If assertion is true but reason is falseD. If the assertion and reason both are false |
| Answer» Correct Answer - c | |
| 132. |
A car is moving with a constant speed of `60 km h^-1` on a straight road. Looking at the rear view mirror, the driver finds that the car following him is at a distance of `100 m` and is approaching with a speed of `5 km h^-1`. In order to keep track of the car in the rear, the driver begins to glane alternatively at the rear and side mirror of his car after every `2 s` till the other car overtakes. If the two cars were maintaining their speeds, which of the following statement (s) is/are correct ?A. The speed of the car in the rear is `65 km h^-1`.B. In the side mirror, the car in the rear would appear to approach with a speed of `5 km h^-1` to the driver of the leading car.C. In the rear view mirror, the speed of the approaching car would appear to decrease as the distance between the cars decreases.D. In the side mirror, the speed of the approaching car would appear to increase as the distance between the cars decreases. |
|
Answer» Correct Answer - D As is known, in the side mirror, the speed of approaching car would appear to increase as the distance between the cars decreases. Choice (d) is correct. |
|
| 133. |
A person runs with a speed u towards a bicycle moving away from him with speed v . The person approaches his image in the mirror fixed at the rear of bicycle with a speed ofA. `u - v`B. `u - 2v`C. `2u - v`D. `2(u - v)` |
| Answer» Correct Answer - d | |
| 134. |
For a normal eye, the cornea of eye provides a converging power of `40 D` and the least converging power of the eye lens behind the cornea is `20 D`. Using this information, the distance between the retina and the cornea eye lens can be estimated to beA. 5cmB. 2.5cmC. 1.67cmD. 1.5cm |
|
Answer» Correct Answer - C Given power `(P_(1))=40D` and power `(P_(2))=20D` We have, `P_("eq")=P_(1)+P_(2)=40+20=60D` `"So," (1)/(f_("eq"))=(1)/(f_(1))+(1)/(f_(2))` `Rightarrow f_("eq")=(100)/(P_("eq"))=(100)/(60)=1.67cm` |
|
| 135. |
For a normal eye, the cornea of eye provides a converging power of `40 D` and the least converging power of the eye lens behind the cornea is `20 D`. Using this information, the distance between the retina and the cornea eye lens can be estimated to beA. 5 cmB. 2.5 cmC. 1.67 cmD. 1.5 cm |
|
Answer» Correct Answer - C Given, power `(P_(1)) = 40 D` and power `(P_(2))=20 D` We have, `P_("eq")=P_(1)+P_(2)=40+20=60 D` So, `" "(1)/(f_("eq"))=(1)/(f_(1))+(1)/(f_(2))` `rArr " " f_("eq")=(100)/(P_("eq"))=(100)/(60)` `= 1.67 cm` |
|
| 136. |
A dentist concave mirror has a radius of curvature of `30 cm`. How far must it be placed from a small cavity in order to get a virtual image magnified `5` times ? |
|
Answer» Correct Answer - 1.2 cm |
|
| 137. |
In an astronomical telescope, the focal length of the objective lens is 100 cm and of eye-piece is 2 cm . The magnifying power of the telescope for the normal eye isA. 50B. 10C. 100D. `(1)/(50)` |
|
Answer» Correct Answer - A Magnification of astronomical telescope for normal eye is, `m=(f_(o))/(f_(e ))=-(100)/(2)=-50` |
|
| 138. |
In an astronomical telescope, focal length of objective lens is `75 cm` and that of eye piece is `5 cm` . Calculate the magnifying power and the distance between the two lenses, when final image of distant object is seen at a distance of `25 cm` from the eye. |
|
Answer» Here, `f_0 = 75 cm, f_e = 5 cm, m = ?` `L = ? D = 25 cm` `m = -(f_0)/(f_e)(1 + (f_e)/(d))` =`-(75)/(5) (1 + (5)/(25)) = -15 xx (6)/(5) = - 18` From `(1)/(v_e)-(1)/(u_e) = (1)/(f_e)` `- (1)/(u_e)=(1)/(f_e)-(1)/(v_e)=(1)/(5)-(1)/(-25)=(6)/(25)` `u_e = (-25)/(6) = -4.17 cm` Distance between the two lenses, `L = f_0 + |u_e|` =`75 + 4.17 = 79.17 cm`. |
|
| 139. |
The magnifying power of an astronomical telescope is 8 and the distance between the two lenses is `54 cm`. The focal length of eye lens and objective lens will be respectivelyA. 6 cm and 48 cmB. 48 cm and 6 cmC. 8 cm and 64 cmD. 64 cm and 8 cm |
| Answer» Correct Answer - a | |
| 140. |
In which, microscope or telescope, the difference in the focal lengths of the two lenses is larger ? |
| Answer» In a telescope, the difference in the focal lengths of two lenses is larger. | |
| 141. |
Assertion `:` If objective and eye lenses of a microscope are interchanged then it can work as telescope. Reason `:` The objective of telescope has small focal length.A. If both assertion and reason are true and the reason is the correct explanation of the assertionB. If both assertion and reason are true but reason is not the correct explanation of the assertionC. If assertion is true but reason is falseD. If the assertion and reason both are false |
| Answer» Correct Answer - d | |
| 142. |
Using the data given below, state which two of the given lenses will you prefer to construct a best possible (i) telescope (ii) microscope. Also, indicate which of the selected lenses is to be used as an objective and as an eye piece in each case Lenses,`L_1, L_2,L_3` Power(P), 6 D,3 D, 10 D Aperture (A), 1 cm, 8 cm, 1 cm. |
|
Answer» For a telescope, lens `L_2` is chosen as objective, as its aperture is largest. The lens `L_3` is chosen as eye piece as its focal length is smallest. For a microscope, lens `L_3` is chosen as objective because its focal length is smallest. Lens `L_1` serves as eye piece because its focal length is not largest. This is required to secure greater magnifying power of the microscope. |
|
| 143. |
The apparent depth of water in cylindrical water tank of diameter `2R cm` is reducing at the rate of `x cm // min ` when water is being drained out at a constant rate. The amount of water drained in `c.c.` per minute is `(n_(1)=` refractive index of air, `n_(2)=` refractive index of water )A. `x pi R^(2) n_(1)//n_(2)`B. `x pi R^(2) n_(2)//n_(1)`C. `2 pi R n_(1)//n_(2)`D. `pi R^(2) x` |
| Answer» Correct Answer - b | |
| 144. |
In an experiment to find focal length of a concave mirror, a graph is drawn between the magnitudes of (u) and (v). The graph looks like.A. B. C. D. |
| Answer» Correct Answer - c | |
| 145. |
A screen is placed 90 cm from an object. The image an object on the screen is formed by a convex lens two different locations separated by 20 cm. the focus length of the lense isA. 18 cmB. 21.4 cmC. 60 cmD. 96.25 cm |
| Answer» Correct Answer - B | |
| 146. |
An observer can see through a pin-hole the top end of a thin rod of height h, placed as shown in the figure. The beaker height is 3h and its radius h. When the beaker is filled with a liquid up to a height 2h, he can see the lower end of the rod. Then the refractive index of the liquid is A. `5//2`B. `sqrt((5//2))`C. `sqrt((3//2))`D. `3//2` |
| Answer» Correct Answer - B | |
| 147. |
A glass prism `(mu = 1.5)` is dipped in water `(mu = 4//3)` as shown in figure. A light ray is incident normally on the surface AB . It reaches the surface BC after totally reflected, if A. `sin theta ge 8//9`B. `2//3 lt sin theta lt 8//9`C. `sin theta le 2//3`D. It is not possible |
| Answer» Correct Answer - A | |
| 148. |
A ray of light is incident at the glass-water interface at an angle I, it emerges fimally parallel to the surface of water, the the value of `mu_g` would be A. `(4//3) sin i`B. `1//sin i`C. `4//3`D. s |
| Answer» Correct Answer - B | |
| 149. |
STATEMENT-`1` The minimum slit separation of a interfernce to produce at least one maximum other than centeral maximum in`YDSE"is" 3`. STATEMENT2 for amaximum ,path difference = n.The maximum value of path difference =`d`,silt separation.A. STATEMENT -`1`is true statement `2` is true,Statement -`2`is a correct explanation for statement -`1`B. STATEMENT -`1`is true statement `2` is true,Statement -`2`is a not a correct explanation for statement -`1`C. Statement -`1`is true,Statement -`2`is FalseD. Statement -`1`is False ,Statement -`2`is True |
|
Answer» Correct Answer - D `Deltax=d=n lambda` For`n=1,d=lambda`and we will have three maximum. |
|
| 150. |
A ray of light undergoes ……… on passing through a prism. |
| Answer» Correct Answer - two refractions | |