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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.
| 601. |
A light ray is incident upon a prism in minimum deviation position and suffers a deviation of `34^(@)`. If the shaded half of the prism is knocked off, the ray will A. Suffer a deviation of `34^(@)`B. Suffer a deviation of `68^(@)`C. Suffer a deviation of `17^(@)`D. Not come out of the prism |
| Answer» Correct Answer - c | |
| 602. |
Light from sodium lamp is passed through cold sodium vapours the spectrum of transmitted light consists ofA. The `D_(1)` and `D_(2)` bright yellow lines of sodiumB. Two dark lines in the yellow regionC. All colours from violet to redD. No colours at all |
| Answer» Correct Answer - b | |
| 603. |
A prism ABC of angle `30^(@)` has its face AC silvered. A ray of light incident at an angle of `45^(@)` at the face AB retraces its path after refraction at face AB and reflection at face AC . The refractive index of the material of the prism is A. 1.5B. `(3)/(sqrt2)`C. `sqrt2`D. `(4)/(3)` |
| Answer» Correct Answer - c | |
| 604. |
A ray of light is incident on the hypotenuse of a right-angled prism after travelling parallel to the base inside the prism. If `mu` is the refractive index of the material of the prism, the maximum value of the base angle for which light is totally reflected from the hypotenuse isA. `sin^(-1) ((1)/(mu))`B. `tan^(-1) ((1)/(mu))`C. `sin^(-1) ((mu - 1)/(mu))`D. `cos^(-1) ((1)/(mu))` |
| Answer» Correct Answer - D | |
| 605. |
A ray of light is incident on the hypotenuse of a right-angled prism after travelling parallel to the base inside the prism. If `mu` is the refractive index of the material of the prism, the maximum value of the base angle for which light is totally reflected from the hypotenuse isA. `sin^(-1) ((I)/(mu))`B. `tan^(-1) ((1)/(mu))`C. `sin^(-1) ((mu-1)/(mu))`D. `cos^(-1)((1)/(mu))` |
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Answer» Correct Answer - D |
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| 606. |
In a compound microscope the objective of `f_(o)` and eyepiece of `f_(e)` are placed at distance `L` such that `L` equalsA. `f_(o)+f_(e)`B. `f_(o)-f_(e)`C. Much greater than `f_(o)` or `f_(e)`D. Much less than `f_(o)` or `f_(e)` |
| Answer» Correct Answer - c | |
| 607. |
For a compound microscope, the focal length of object lens and eye lens are `f_(o)` and `f_(e)` respectively, then magnification will be done by microscope whenA. `f_(o) = f_(e)`B. `f_(o) gt f_(e)`C. `f_(o) lt f_(e)`D. None of these |
| Answer» Correct Answer - c | |
| 608. |
An air bubble in a jar of water shines brightly. Why ? |
| Answer» Light entering water in the jar is totally reflected from the air bubble. The observer feels this light is coming from the bubble. So the bubble appears to shine. | |
| 609. |
Assertion `:` The setting sun apears to be red. Reason `:` Scattering of light is directly proportional to the wavelength .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 | |
| 610. |
Light of different colours propagates through airA. With the velocity of airB. With different velocitiesC. With the velocity of soundD. Having the equal velocities |
| Answer» Correct Answer - d | |
| 611. |
What is the refractive index of a medium in which light travels with a speed of `2 xx 10^8 m//s` ?A. `3//2`B. `2//3`C. 1D. none of these |
| Answer» Correct Answer - A | |
| 612. |
The image of point `P` when viewed from top of the slabs will be A. 2.0 cm above PB. 1.5 cm above PC. 2.0 cm below PD. 1 cm above P |
| Answer» Correct Answer - d | |
| 613. |
When light travels from one medium to the other of which the refractive index is different, then which of the following will changeA. Frequency, wavelength and velocityB. Frequency and wavelengthC. Frequency and velocityD. Wavelength and velocity |
| Answer» Correct Answer - d | |
| 614. |
How much water should be filled in a container 21 cm in height, so that it appaers half filled when viewed from the top of the contaier? [Given that : `""_(a) mu _(w) = (4)/(3)` ]A. 8.0 cmB. 10.5 cmC. 12.0 cmD. None of these |
| Answer» Correct Answer - c | |
| 615. |
A light wave has a frequency of `4xx10^(14)Hz` and a wavelength of `5xx10^(-7)` meters in a medium. The refractive index of the medium isA. 1.5B. 1.33C. `1.0`D. `0.66` |
| Answer» Correct Answer - a | |
| 616. |
A light wave has a frequency of `4xx10^(14)Hz` and a wavelength of `5xx10^(-7)` meters in a medium. The refractive index of the medium isA. 1.5B. 1.33C. 1.25D. 1.7 |
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Answer» Correct Answer - A (a) Refractive index of the medium, `mu=(c)/(v)=(c)/(nlambda)=(3xx10^(8))/(4xx10^(14)xx5xx10^(-7))=1.5` |
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| 617. |
Absolute refractive indices of glass and water are `3//2` and `4//3`. The ratio of velocity of light in glass and water will beA. `4 : 3`B. `9 : 8`C. `8 : 9`D. `3 : 4` |
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Answer» Correct Answer - C (c ) As, `µ=(c)/(v)rArrvprop1/µ` `therefore` `v_(1)/v_(2)=µ_(1)/µ_(2)` `rArr` Ratio of velocities of light `v_(g)/v_(w)=µ_(w)/µ_(g)=(4//3)/(3//2)=8/9` |
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| 618. |
The refractive index of glass with respect to air is `3/2` and the refraction index of water with respect to air is `4/3`. The refractive index of glass with respect to water will be:A. `8//9`B. `9//8`C. `7//6`D. None of these |
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Answer» Correct Answer - B (b) Refractive index of glass with respect to water, `""_(w)µ_(g)=(""_(a)mu_(g))/(""_(a)mu_(g))=(3//2)/(4//3)=(9)/(8)` |
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| 619. |
STATEMENT-`1` Law of reflection is applicable for all type of mirrors. `STATEMENT 2`Rays which are parallel to principal axis are known as paraxial rays.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 |
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Answer» Correct Answer - C Rays whichare near and parallel to principal axis are known as paraxial axis. |
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| 620. |
Light wave enters from medium 1 to medium 2. Its velocity in `2^(nd)` medium is double from `1^(st)`. For total internal reflection the angle of incidence must be greater thanA. `30^(@)`B. `60^(@)`C. `45^(@)`D. `90^(@)` |
| Answer» Correct Answer - a | |
| 621. |
Optical fibres are related withA. CommunicationB. LightC. ComputerD. None of these |
| Answer» Correct Answer - a | |
| 622. |
Assertion : Optical fibres make use of total internal reflection. Reason : Light undergoes successive total internal reflections as it moves through an optical fibre.A. If both assertion and reason are true and reason is the correct explanation of assertion.B. If both assertion and reason are true and reason is not the correct explanation of assertion.C. If assertion is true but reason is false.D. If both assertion and reason are false. |
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Answer» Correct Answer - B Optical fibres are fabricated with high quality composite glass or quartz fibres. Each fibre consists of a core and cladding. The refractive index of the material of the core is higher than that of the cladding. When a signal in the form of light is directed at one end of the fibre at a suitable angle, it undergoes repeated total internal reflections along the length of the fibre and finally comes out at the other end. |
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| 623. |
A candle placed 25 cm from a lens, forms an image on a screen placed 75 cm on the other end of the lens. The focal length and type of the lens should beA. `+ 18.75 cm` and convex lensB. ` – 18.75 cm` and concave lensC. `+ 20.25 cm` and convex lensD. `– 20.25 cm` and concave lens |
| Answer» Correct Answer - a | |
| 624. |
The relation between `n_(1)` and `n_(2)` , if behaviour of light rays is as shown in figure is A. `n_(1) gt gt n_(2)`B. `n_(2) gt n_(1)`C. `n_(1) gt n_(2)`D. `n_(1) = n_(2)` |
| Answer» Correct Answer - b | |
| 625. |
Chromatic aberration of lens can be corrected byA. Reducing its aperatureB. Proper polishing of its two surfacesC. Suitably combining it with another lensD. Providing different suitable curvature to its two surfaces |
| Answer» Correct Answer - c | |
| 626. |
STATEMENT-`1` A single lens cannot be free from chromatic aberration `STATEMENT 2` When light passes through single lens dispersion must occurA. 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 - A | |
| 627. |
STATEMENT-`1` When a glass prism is Immesed in water ,the deviation caused by prism decreases. `STATEMENT 2`Refractive index of glass prism relative to water is less than relative to air.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 - A | |
| 628. |
A beaker containing liquid is placed on a table, underneath a microscope which can be moved along a vertical scale. The microscope is focused, through the liquid onto a mark on the table when the reading on the scale is `a`. It is next focused on the upper surface of the liquid and the reading is `b`. More liquid is added and the observations are repeated, the corresponding readings are `c` and `d`. The refractive index of the liquid isA. `(d - b)/(d - c - b + a)`B. `(b - d)/( d - c - b + a)`C. `(d - c - b + a)/(d - b)`D. `(d - b)/(a + b - c - d)` |
| Answer» Correct Answer - a | |
| 629. |
The time required to pass the light through a glass slab of 2 mm thick is `(mu_("glass")=1.5)`A. `10^(-5) s`B. `10^(-11) s`C. `10^(-9) s`D. `10^(-13) s` |
| Answer» Correct Answer - b | |
| 630. |
The refractive index of water is 1.33. What will be the speed of light in waterA. `3xx10^(8) m//s`B. `2.25xx10^(8) m//s`C. `4xx10^(8) m//s`D. `1.33xx10^(8) m//s` |
| Answer» Correct Answer - b | |
| 631. |
Ray optics is valid when characteristic dimensions areA. Of the same order as the wavelength of lightB. Much smaller than the wavelength of lightC. Of the order of one millimetreD. Much larger than the wavelength of light |
| Answer» Correct Answer - d | |
| 632. |
Radii of curvature of a canverging lends are in the ration 1:2. Its focal length is 6cm and refractive index is 1:5. Then, its radii of curvature are…A. 9cm and 18cmB. 6cm and 12cmC. 3cm and 6cmD. 4.5cm and 9cm |
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Answer» Correct Answer - D Given `(R_(1))/(R_(2))=(1)/(2),f=6`cm and `mu=1.5` Let, `R_(1)=R and R_(2)=2R` We know that the focal length of converging lens by using releationg , `(1)/(f)=(mu-1)[(1)/(R_(1))-(1)/(R_(2))]` Substituting all the values, we get `R=4.5cm` `R_(1)=4.5cm` and `R_(2)=2xx4.5=9cm` |
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| 633. |
The sun light reaches us as white and not as its components becauseA. air medium is dispersiveB. air medium is non dispersiveC. air medium scatter the sunlightD. spped of light depends on wavelength in vaccum |
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Answer» Correct Answer - B The sun light reaches us as white light and not as its components because air medium is non-dispersive. |
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| 634. |
The radius of curvature of the convex face of a plano convex lens is 12cm and the refractive index of the material of the lends 1.5. Then, the focal length of the lens isA. 6cmB. 12cmC. 18cmD. 24cm |
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Answer» Correct Answer - D We know that, `(1)/(f)=(n-1)(1)/(R )` Given, R=12cm and r=1.5 Here, `f=(R)/(n-1)=(12)/(1.5-1)=(12)/(0.5)=24cm` |
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| 635. |
The radius of curvature of the convex surface of a thin plano-convex lens is 15 cm and the refractive index of its material is 1.6. The power of the lens isA. `+1 D`B. `-2 D`C. `+3D`D. `+4 D` |
| Answer» Correct Answer - d | |
| 636. |
Two lenses of power`+2.50D`and`-3.75D`are combined to form a compound lens Its focal length in cm,will beA. 40B. -40C. -80D. 160 |
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Answer» Correct Answer - 3 `P=P_(1)+P_(2)` `P=2.50-3.75=-1.25D` `:.f=(1)/(P)` or`f=(1)/((-1.25))=-0.8m` `f=-80cm` |
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| 637. |
Two lenses of power `+12` and `-2` dioptres are placed in contact. The combined focal length of the combination will beA. `8.33 cm`B. `1.66 cm`C. `12.5 cm`D. `10 cm` |
| Answer» Correct Answer - d | |
| 638. |
It is desired to make an achromatic combination of two lenses, `(L_(1)& L_(2))` made of materials having dispersive power `omega_(1)` and `omega_(2)(ltomega_(1))`. If the combination of lenses is converging then:A. `L_(1)` is convergingB. `L_(2)`is convergingC. Power of `L_(1)`is greater than the power of `L_(2)`D. None of these |
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Answer» Correct Answer - B Condition for achromatism `(omega_(1))/(f_(1))+(omega_(2))/(f_(2))=0` `(omega_(1))/(omega_(2))=-(f_(1))/(f_(2))` Given that`omega_(1)gtomega_(2)` `(omega_(1))/(omega_(2))gt1` `-(f_(1))/(f_(2))gt1` `f_(1)gtf_(2)`and of opposite nature So,`P_(1) ltP_(2)`For focal length of combination `(1)/(f)=(1)/(f_(1))+(1)/(f_(2))` `P=P_(1)+P_(2)` Since the combination of lens is converging that means `Pgt0`,,So power of`L_(2)` must be greater & must be positive .option (B)is correct choice. |
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| 639. |
Focal length of convex lens will miximum forA. Blue lightB. Yellow lightC. Green lightD. Red light |
| Answer» Correct Answer - d | |
| 640. |
Two lenses of power 6 D and – 2 D are combined to form a single lens. The focal length of this lens will beA. `3/2 m`B. `1/4 m`C. `4 m`D. `1/8 m` |
| Answer» Correct Answer - b | |
| 641. |
The focal lengths for violet, green and red light rays are `f_(V), f_(G)` , and `f_(R)` respectively. Which of the following is the true relationshipA. `f_(R) lt f_(G) lt f_(V)`B. `f_(V) lt f_(G) lt f_(R)`C. `f_(G) lt f_(R) lt f_(V)`D. `f_(G) lt f_(V) lt f_(R)` |
| Answer» Correct Answer - b | |
| 642. |
A lens if placed between a source of light and a wall. It forms images of area` A_(1)` and `A_(2)` on the wall for its two different positions. The area of the source or light isA. `(A_(1)+A_(2))/(2)`B. `[1/A_(1)+1/A_(2)]^(-1)`C. `sqrt(A_(1)A_(2))`D. `[(sqrt(A_(1))+sqrt(A_(2)))/(2)]^(2)` |
| Answer» Correct Answer - c | |
| 643. |
The power of an achromatic convergent lens of two lenses is + 2 D . The power of convex lens is + 5 D . The ratio of dispersive power of convex and concave lens will beA. `5:3`B. `3:5`C. `2:5`D. `5:2` |
| Answer» Correct Answer - b | |
| 644. |
The focal lengths of convex lens for red and blue light are 100 cm and 96.8 cm respectively. The dispersive power of material of lens isA. `0.325`B. `0.0325`C. `0.98`D. `0.968` |
| Answer» Correct Answer - b | |
| 645. |
Light travels in two media A and B with speeds `1.8 × 10^(8) m s^(–1) and2.4 × 10^(8) m s^(–1)` respectively. Then the critical angle between them isA. `sin^(-1)(2/3)`B. `tan^(-1)(3/4)`C. `tan^(-1)(2/3)`D. `sin^(-1)(3/4)` |
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Answer» Correct Answer - D (d) We have, `C=sin^(-1)(v_(1)/v_(2))=sin^(-1)(3/4)` |
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| 646. |
Two plane mirrors are at `45^(@)` to each other. If an object is placed between them, then the number of images will beA. 5B. 9C. 7D. 8 |
| Answer» Correct Answer - c | |
| 647. |
The focal length of a thin convex lens for red and blue colours is 100.5 cm and 99.5 cm .The dispersive power of the lens isA. 0.01B. 0.02C. 1.005D. 0.995 |
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Answer» Correct Answer - A (a) We have, `f_(y)=sqrt(f_(R)f_(b))` `f_(y)=sqrt(100.5xx99.5)=99.99` Also, omega=`(f_(R)-f_(b))/(f_(y))=(100.5-99.5)/99.99` Dispersive power,omega=`1/99.99=0.01` |
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| 648. |
Angular resolving power of human eye isA. `3.6xx10^(3)`radB. `3.6xx10^(2)`radC. `3.6xx10^(4)`radD. `3.6xx10^(6)`rad |
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Answer» Correct Answer - A (a) The mjnimum angular separation between two objects, so that they are just resolved is called resolving limit. For eye it is `1=[1/60]^(@)`. Reciprocal of resolving limit is clled resolving power (RP), `=1/(1/60)^(@)=1/(1/60xxpi/180)` `10800/pi=3.436xx10^(3) rad` |
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| 649. |
Two mirrors are placed at right angle to each other. A man is standing between them combining his hair. How many images he will see?A. 2B. 3C. 1D. zero |
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Answer» Correct Answer - B (b) The number of images formed depends upon the angle between the mirrors. If two mirrors make an angle `theta` with each other, then the number of images formed is `n=360^(@)/theta-1` when mirrors are kept mutually perpendicular to each other, then `theta=90^(@)` `n=360^(@)/90^(@)-1=3` |
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| 650. |
If two mirrors are keps at `60^circ` to each other, then the number of images formed by them isA. sixB. fourC. fiveD. three |
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Answer» Correct Answer - C (c ) As,m=`360^(@)/60^(@)`=6 Since, m is an even integer, total number of images will be (m-1) or 5. |
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