45406 + Interview Questions in Physics in Class 12

1.	What is the meaning of the word 'alter'?
Answer» PLACE for WEDDING ceremonies To make something different in some way, but WITHOUT changing it completely To win in an argument All of the above Answer :B

Discussion

2.	Four small objects each of mass m are fixed at the comers of a rectangular wire-frame of negligible mass and of sides a and b (a gt b ). If the wire frame is now rotated about an axis passing along the side of length b, then the moment of inertia of the system for this axis of rotation is
Answer» `2ma^(2)` `4ma^(2)` `2m(a^(2)+b^(2))` `2m(a^(2)-b^(2))` SOLUTION :Moment of inertia of a rectangular wire FRAME about an AXIS passing through along the side b. `I=ma^(2)+0+ma^(2)+0=2ma^(2)`

Discussion

3.	if three are N atoms in a source of laser light and each atom is emitting light with intensityl, then the total intensity produced by it is
Answer» NI `N^2I` `N^3I` `N^4I` SOLUTION :NA

Discussion

4.	Two waves of same frequency and intensity superimpose on each other in opposite phases. After the superposition. The intensity and frequency of waves will
Answer» increases decreases REMAIN constant Become zero Answer :D

Discussion

5.	Choose the correct statements from the following
Answer» Like other LIGHT nuclei, the 2He4 nuclei also have a low VALUE of the binding energy per NUCLEON The binding energy per nucleon decreases for nuclei with small as well as large atomic number. The energy required to remove one neutronfrom `._(3)Li^(7)` to transform it into the ISOTOPE `._(3)Li^(6)` is 5.6 MeV, which is the same as the binding energy per nucleon of `._(3)Li^(6)`. When two deuterium nuclei fuse together, theygive rise to a TRITIUM nucleus accompanied by a release of energy. Answer :B::C

Discussion

6.	While a collector-emitter voltage is constant in a transistor, the collector current changes by 8.2mA when the emitter current changes by 8.3mA. The change in base current is
Answer» `100muA` `200 MUA` `300 muA` `400 muA` ANSWER :A

Discussion

7.	A train starting from rest travels the first part of its journey with constant acceleration a , second part with constant velocity v and third part with constant retardation a, being brough to rest. The average speed for the whole journely is (7v)/(8) . For what fraction of the total time, the train travels with constant velocity ?
Answer» `1//2` `3//4` `5//3` `5//8` ANSWER :B

Discussion

8.	Spherical waves are emitted from a 1.0 watt source in an isotropic non-absorbing medium. What is the wave intensity 1.0 m from the source?
Answer» SOLUTION :`1/(4PI)WATT //m^2`

Discussion

9.	In the figure shown three slits s_(1),s_(2) and s_(3) are illuminated with of wavelength lambda.lambda ltltd and D gtgt d. Each slit prouduces same intensity I on the screen. If intensity at the point on screen directly infront of s_(2) is 3I then the maximum value of lambda is (nd^(2))/(2D) Find value of n.
Answer» SOLUTION :N//a

Discussion

10.	The speed of water is double that of swimmer's velocity relative to water ?What should be the direction of the swimmer so as to express minimum displacement assuming v_m= 5m//sec ?
Answer» SOLUTION :Putting the value of `(V_(mw))/(V_(W))=(1)/(2)` in the derived expression `THETA`= `sin^(-1)(V_(mw))/(V_(w))` we obatin `theta=sin^(-1)((1)/(2))=30^(@)implies 120^(@)` from direction of river flow

Discussion

11.	SI unit of magnetic field intensity is _____ or T .
Answer» SOLUTION :`"WEB"/m^2`

Discussion

12.	Explain quantitatively the order of magnitude diff ere nee between the diamagnetic susceptibility of N_(2) (-5 xx 10^(-9) ) (at STP) and Cu (-10^(-5) ).
Answer» Solution :MAGNETIC susceptibility is the property of the SUBSTANCE which shows how easily a substance can be magnetised. Density of `N_(2)`, `(rho)N_(2) =- (28 g) /( 22.4 L) = (28 g)/( 22,400 cm^(3) ) ""…(1)` Density of copper, `(rho)_(Cu) = (8g)/( cm^(3) )""...(2)` Taking the ratio of equation (1) and (2), `therefore ((rho)N_2 )/( (rho ) Cu) = (((28)/( 22,400)))/( 8)` `=0.0001562` `=1.562 xx 10^(-4)` `((rho) N)_(2) ) /( (rho)_(Cu) )= 1.6 xx 10^(-4)""...(3)` Magnetic susceptibility of given MATERIAL, `CHI = ("Magnetisation (M)")/( " Magnetic intensity (H)")` `= ("Magnetic dipole moment per volume")/( " H")` `((("Magnetic dipole moment" m) /( "Volume V")))/(H)"` `chi = (m) /( HV)""...(4)` but density `rho = ("MASS" m.)/( "volume V")` `therefore V= (m.)/( rho) ""...(5)` `therefore chi = ((m)/( H_m) .)rho ` Taking terms of bracket as constant, Thus `chi xx rho ""...(6)` `therefore ((chi) N_2) /( (chi ) Cu)= ((rho) N_2) /((rho) (Cu) ) ""...(7)` Putting the value of equation (3) in equation (7), `((chi) N_2 )/( (chi) Cu ) = 1.6 xx 10^(-4) ""...(8)`

Discussion

13.	When a thin wedge-shaped film is illuminated by a parallel beam of light of wavelength 6000 overset()A, 7 fringes are observed in a certain region of the film. How many fringes will be observed in the same region of the film if light of wavelength 4200 overset()A is used ?
Answer» 6 10 14 18 Answer :B

Discussion

14.	Consider a hypothetical annihilation of a stationary electron with a stationary position, what is wavelength of resulting radiation?
Answer» ANSWER :`H/(m_(0)C)`

Discussion

15.	Do all the photons have same dynamic mass ? If not, Why ?
Answer» SOLUTION :`E=mc^2,HV=mc^2,m=(hv)/(C^2)`, no, it DEPENDS UPON FREQUENCY.

Discussion

16.	Satellite communication is generally carried out for frequencies above
Answer» 1MHz 1kHz 20 MHz 20kHz Answer :C

Discussion

17.	The angle of incidence for a ray of light passing through the centre of curvature of a concave mirror is :
Answer» `45^(@)` `90^(@)` `0^(@)` `180^(@)` Answer :C

Discussion

18.	In a longitudinal stationary wave produced in a gas, pressure changes are maximum
Answer» At the nodes None of the above At the antinodes At all points Answer :C

Discussion

19.	Whenever a hydrogen atom emits a photon in the Balmer series ,
Answer» it MUST emit another photon in the Balmer series it must emit another photon in the Lyman series the SECOND photon, if emitted will have a wavelenth of about 122 NM it may emit a second photon, but the wavelength of this photon cannot be PREDICTED Answer :B::C

Discussion

20.	For a projectile , the angle of projection for which the horizontal range equal to the maximum height attained by the projectile will be
Answer» `tan^-1 4` `tan^-1 2` `tan^-1` 1/4 `tan^-1` (1/2) ANSWER :A

Discussion

21.	Due to a certain redistribution of masses, the totment of inertia of a rotating body about the axis of retation increases by 50%. The torque acceleration of the body should be
Answer» INCREASED to 2 times reduced to half increased to 1.5 times increased to 3 times Answer :C

Discussion

22.	The half life of a substance A is 1 h. The half life of another substance B is 10 years. A mixture of the two substances has an activity of 1000 Bq. After 1 h, its activity drops to 900 Bq. What will be its acitivity after 20 years?
Answer» ANSWER :200Bq

Discussion

23.	A human wave. During sporting events within large, density packed stadiums, spectators will send a wave (or pulse) around the stadium (Fig. 16-44). As the wave reaches a group of spectators, they stand with a cheer and then sit. At any instant, the width w of the wave is the distance froin the leading edge (people are just about to stand) to the trailing edge (people have just sat down). Suppose a human wave fravels a distance of 853 seats around a stadium in 51 s, with spectators requiring about 1.8 s to respond to the wave's passage by stand- ing and then sitting. What are (a) the wave speed v in seats per second) and (b) width w (in number of sears)?
Answer» ANSWER :(a) 17 SEATS/s; (B) 30 seats

Discussion

24.	What is angle of minimum deviation?
Answer» Solution :The minimumvalue of the ANGLE of DEVIATION SUFFERED by a RAY on passing through a prism a refracting medium is called desperison.

Discussion

25.	Is the resistance of an ammeter greater than or less than that of the galvanometer of which it is formed?
Answer» SOLUTION :It is ALWAYS LESS than the RESISTANCE of the GALVANOMETER.

Discussion

26.	For a CE transistor amplifier, the audio signal voltage across the collector resistance of 2k Omega is 2V. Suppose the current amplification factor of the transistor is 100. The value of R_(B) in series with V_(BB) supply of 2V, if the DC base current has to be 10 times the signal current is.
Answer» `7kOmega` `26kOmega` `10KOMEGA` `14kOmega` ANSWER :D

Discussion

27.	In comparing the resistance of two coils P and Q with the help of a metre-bridge arrangement, a balance point is obtained when the sliding contact is 50 cm from the zero end of the wire. The resistances P and Q are then interchanged and balance point is obtained at 120 cm from the zero end. Deduce the ratio of the resistances P and Q and the length of the wire.
Answer» ANSWER :`5:12,170cm`

Discussion

28.	If the coefficient of mutual induction of the primary and secondary coils of an induction coil is 6H and a current of 5A is cut off in 1/5000 second, calculate the emf induced in the secondary coil.
Answer» Solution :`e= -M (DI)/(DT)` `e= 6 xx (5)/(1//5000) V= 15 xx 10^(-4)V`

Discussion

29.	The camera lens has an aperture of f and the exposure time is 1/60 s. What will be the new exposure time if the aperture become 1.4 f?
Answer» `(1)/(42)s` `(1)/(56)s` `(1)/(72)s` `(1)/(31)s` Solution :TIME of EXPOSURE `prop (f - "number")^(2)` `therefore(t)/(((1)/(60)))=((1.4)/(1))^(2)rArrt=(1.4xx1.4)/(60)APPROX(1)/(31)s`

Discussion

30.	A ray of light passing through a prism having mu =sqrt2 suffers minimum deviation. It is found that the angle of incidence is double the angle of refraction within the prism. What is the angle of prism.
Answer» SOLUTION :As the prism is in the position of MINIMUM deviation.`delta_m =(2i - A)` with r=A/2 According to given problem, `i = 2R = A (as r = A/2]` `delta_m = 2A - A = A` and hence from `mu = ( sin[ A+ delta_m)//2])/(sin (A//2))i.e., sqrt(2)= ( sin A)/(sin A//2)` (or) `sqrt(2)sin (A )/( 2 )= 2 sin(A )/(2)cos (A )/(2) i.e.,cos ""(A)/(2) =(1)/( sqrt(2)) `(or ) `A/2 = cos^(-1) [(1)/(sqrt2)]=45^@ ,i.e.,,A=90^@`

Discussion

31.	Heat produced in a resistance wire of resistance R on passing current is H cal/sec.Then current through resistor = ...... A.
Answer» `SQRT((H)/(R)) ` `sqrt((H)/(Rt))` `sqrt((Ht)/(R))` `(HJ)/(R)` SOLUTION :`sqrt((HJ)/(R))` H = `(I^(2)R)/(J)therefore I^(2) = (11J)/(R) "" therefore I = sqrt((HJ)/(R))`

Discussion

32.	What are the maximum number of rectangular components of a vector can be split in space and in plane respectively
Answer» 3,2 3,3 2,2 `OO,oo` ANSWER :A

Discussion

33.	(A): Two particles of same charge projected with different velocity normal to electric field experience same force (R ): A charged particle experiences force, independent of velocity in electric field
Answer» Both .A. and .R. are TRUE and .R. is the CORRECT EXPLANATION of .A. Both .A. and .R. are TRU and .R. is not the correct explanation of .A. A. is true and .R. is false A. is false and .R. is true Answer :A

Discussion

34.	State basic properties of em. Waves.
Answer» SOLUTION :Gauss.s LAW of ELECTROSTATICS.

Discussion

35.	One face of a prism with a refracting angle of 30^@ is coated with silver. A ray incident on another face at an angle of 45^@ is refracted and reflected from the silver coated face and retraces its path. What is the refractive index of the prism?
Answer» Solution :GIVEN`A=30^@, i_1= 45^@and r_2=0` SINCE ` , r_1+r_2= A` ` thereforer_1=A =30 ^@` Now refractive index of the PRISM, `mu = ( SIN i_1)/( sin r_1) = ( sin45^@ )/(sin 30^@) = ((1)/(sqrt2))/(1/2) = sqrt(2)`

Discussion

36.	The hysterisis loop of material depends not only on the nature of material but also on the history of its magnetization cycles. Suggest a use of this property of material.
Answer» Solution :The value of magnetization is record/memory of its cycles of magnetisation. If INFORMATION bits can be made correspond to these cycles, the SYSTEM displaying such HYSTERISIS loop can act as a device for storing information’s.

Discussion

37.	Assume Eq. 6-29 gives the drag force on a pilot plus ejec-tion seat just after they are ejected from a plane traveling horizontally at 1300 km/h. Assume also that the mass of the seat is equal to the mass of the pilot and that the drag coefficient is that of a sky diver. Making a reasonable guess of the pilot's mass and using the appropriate v, value from Table 6-2, estimate the magnitudes of (a) the drag force on the pilot + seat and (b) their horizontal deceleration (in terms of g), both just after ejection. (The result of (a) should indicate an engineering requirement: The seat must include a protective barrier to deflect the initial wind blast away from the pilot's head.)
Answer» Solution :`(a)D~~2xx10^(4)N,(b)\|a\|=(D)/(2m)=(G)/(2)((V)/(v_(1)))^(2)=18g`

Discussion

38.	Referring to the provious illustration, if the maximum heights for two possible paths are given as H_(1)=3m and H_(2)=9m, find the corresponding angles of projection
Answer» SOLUTION :`H_(1)//H_(2)=(v_(0)^(2)sin^(2)theta)/(2g)div(v_(0)^(2)sin^(2)(90-theta))/(2g)=tan^(2)theta` `rArrtheta=tan^(-1)sqrt((H_(1))/(H_(2)))=tan^(-1)[sqrt((3)/(9))]=.tan^(-1).(1)/(sqrt(3)=30^(@)`

Discussion

39.	Suppose that the same system of charges is now placed in an external electric field E=A(1//r^2),A=9xx10^5Cm^-2. What would the electros -tatic energy of the configuration be ?
Answer» Solution :The mutal INTERACTION energy of the TWO charges REMAINS unchanged. In addition , there is the energy of interaction of the two charges with the external electric FIELD. We find, `q_(1)V(r_1)+q_2V(r_2)=A(7muC)/(0.09m)+A(-2muC)/(0.09m)` and the net electrostatic energy is `q_1V(r_1)+q_2V(r_2)+(q_1q_2)/(4piepsi_0r_12)` `=A(7muC)/(0.09m)+A(-2muC)/(0.09m)-0.7J` `=70-20-0.7=49.3J`.

Discussion

40.	Magnetic intensity is measured in
Answer» `Am^-1` tesla gauss weber. Answer :A

Discussion

41.	Name the device which results in the amplification of signals.
Answer» SOLUTION :AMPLIFIER.

Discussion

42.	The coils, in certain galvanometers, have a fixed core made of a non-magnetic metallic material. Why does the oscillatory coil come to rest so quickly in such a core ?
Answer» Answer :On ACCOUNT of EDDY currents SET up in the metallic core, when the galvanometer coil oscillates in a magnetic field.

Discussion

43.	Assertion:For a perfectly diamagnetic substance permeability is always one. Reason: The ability of a material of permit the passage of magnetic lines of force through it is called magnetic permeability.
Answer» If both assertion and REASON are TRUE and the reason is the correct EXPLANATION of the assertion. If both assertion and reason are true but reason is not the correct explanation of the assertion f assertion is true but reason is FALSE. If assertion is false but reason is true Answer :D

Discussion

44.	A straight rod of light L and mass m is pivoted freely from a point of the roof. Its lower end is connected to an ideal spring of spring constant K. The other end of the spring is connected to the wall as shown in the figure. Find the frequency of small oscillation of the system.
Answer» SOLUTION :`(1)/(2PI) SQRT(3 ((K)/(m) + (g)/(2L)))`

Discussion

45.	If the conjugatefoci of a spherical mirror lie of the same side of the mirror then, what is the nature of the mirror?
Answer» ANSWER :CONCAVE

Discussion

46.	In a arrangement of Young experiment the central fringe of interference pattern produced by light of wavelength 6000 Å so the central fringe is superposing to 4th order dark fringe, after a glass plate of refractive index 1.5 is introduced. The thickness of the glass plate would be ......
Answer» `6xx10^(-6)m` `4.5xx10^(-6)m` `4.2xx10^(-6)m` `4.8xx10^(-6)m` SOLUTION :THICKNESS of PLATE `t=(XD)/(D(mu-1)) ""...(1)` but `(xd)/(D)=(2n-1)(lambda)/(2)` `(xd)/(D)=(7lambda)/(2) ""...(2) n=4` dark `:.` From equation (1) and (2), `t=(7lambda)/(2(mu-1))` `=(7xx6xx10^(-7))/(2(1.5-1.0))=(21xx10^(-7))/(0.5)=4.2xx10^(-6)m`

Discussion

47.	A rod of 5 cm length is moving perpendicular to uniform magnetic field of intensity 2 xx 10^(-4) "Wbm"^(-2). If the acceleration of rod is 2 ms^(-2), the rate of increasing of the induced emf is .......
Answer» `20xx10^(-4) Vs^(-2)` `20xx10^(-4)V` `20xx10^(-4)` Vs `2 xx10^(-5)Vs^(-1)` SOLUTION :The induced EMF `\|epsilon\|=Bvl` `therefore (d\|epsilon\|)/(DT)=d/(dt)(Bvl)` `=B(dv)/(dt)l` [ `because` B and l are constant] =Bal[`because (dv)/(dt)`=a=acceleration] `=2XX10^(-2)xx2xx5xx10^(-2)` `=20xx10^(-4)Vs^(-1)`

Discussion

48.	A metal rod of Young's modulus Y and coefficient of thermal expansion a is held at its two ends such that its length remains invariant. If its temperature is raised by t^(@)C, the linear stress developed in it is:
Answer» `(Y)/(alpha t)` `Y alpha t` `(1)/((Y alpha t)` `(alpha t)/(Y)` Solution :`Y =(F//A)/(DELTA lIl)` So, F=A `Y alpha t` Thermal stress (F/A) `=Y alpha t`. CORRECT choice : (B).

Discussion

49.	In YDSE's experiment performed in a medium of refractive index (4/3), a light of 60 nm wavelength is falling ono the slits having 0.45 mm separation.t he lower slit S_(2) is covered by a thin glass sheet of thickness 10.4mum and refractive index 1.5 the interference pattern is observed on a screen palced 1.5m from the slits as shown int hef ignore dispersion. Q. If white light of range 400-700 nm has replaced 600 nm light, one of the wavelengths of light that forms maxima exactly at point O wll be:
Answer» 650 nm 625 nm 550 nm 605 nm Answer :A

Discussion

50.	Consider sunlightincident on a slit of width 10^(4)A^(0). The image seen through the slit shall :
Answer» be a fine sharp slit WHITE in colour at the CENTRE a BRIGHT slit white at the centre diffusing to ZERO intensities at the edges a bright slit white at the centre diffusing to regions of DIFFERENT colour only be a diffused slit white in colour Answer :A

Discussion

Explore topic-wise InterviewSolutions in Current Affairs.

What is the meaning of the word 'alter'?

Four small objects each of mass m are fixed at the comers of a rectangular wire-frame of negligible mass and of sides a and b (a gt b ). If the wire frame is now rotated about an axis passing along the side of length b, then the moment of inertia of the system for this axis of rotation is

if three are N atoms in a source of laser light and each atom is emitting light with intensityl, then the total intensity produced by it is

Two waves of same frequency and intensity superimpose on each other in opposite phases. After the superposition. The intensity and frequency of waves will

Choose the correct statements from the following

While a collector-emitter voltage is constant in a transistor, the collector current changes by 8.2mA when the emitter current changes by 8.3mA. The change in base current is

Spherical waves are emitted from a 1.0 watt source in an isotropic non-absorbing medium. What is the wave intensity 1.0 m from the source?

The speed of water is double that of swimmer's velocity relative to water ?What should be the direction of the swimmer so as to express minimum displacement assuming v_m= 5m//sec ?

SI unit of magnetic field intensity is _____ or T .

Explain quantitatively the order of magnitude diff ere nee between the diamagnetic susceptibility of N_(2) (-5 xx 10^(-9) ) (at STP) and Cu (-10^(-5) ).

When a thin wedge-shaped film is illuminated by a parallel beam of light of wavelength 6000 overset(*)A, 7 fringes are﻿ observed in a certain region of the film. How many﻿ fringes will be observed in the same region of the film﻿ if light of wavelength 4200 overset(*)A is used ?﻿

Consider a hypothetical annihilation of a stationary electron with a stationary position, what is wavelength of resulting radiation?

Do all the photons have same dynamic mass ? If not, Why ?

Satellite communication is generally carried out for frequencies above

The angle of incidence for a ray of light passing through the centre of curvature of a concave mirror is :

In a longitudinal stationary wave produced in a gas, pressure changes are maximum

Whenever a hydrogen atom emits a photon in the Balmer series ,

For a projectile , the angle of projection for which the horizontal range equal to the maximum height attained by the projectile will be

Due to a certain redistribution of masses, the totment of inertia of a rotating body about the axis of retation increases by 50%. The torque acceleration of the body should be

The half life of a substance A is 1 h. The half life of another substance B is 10 years. A mixture of the two substances has an activity of 1000 Bq. After 1 h, its activity drops to 900 Bq. What will be its acitivity after 20 years?

What is angle of minimum deviation?

Is the resistance of an ammeter greater than or less than that of the galvanometer of which it is formed?

For a CE transistor amplifier, the audio signal voltage across the collector resistance of 2k Omega is 2V. Suppose the current amplification factor of the transistor is 100. The value of R_(B) in series with V_(BB) supply of 2V, if the DC base current has to be 10 times the signal current is.

If the coefficient of mutual induction of the primary and secondary coils of an induction coil is 6H and a current of 5A is cut off in 1/5000 second, calculate the emf induced in the secondary coil.

The camera lens has an aperture of f and the exposure time is 1/60 s. What will be the new exposure time if the aperture become 1.4 f?

A ray of light passing through a prism having mu =sqrt2 suffers minimum deviation. It is found that the angle of incidence is double the angle of refraction within the prism. What is the angle of prism.

Heat produced in a resistance wire of resistance R on passing current is H cal/sec.Then current through resistor = ...... A.

What are the maximum number of rectangular components of a vector can be split in space and in plane respectively

(A): Two particles of same charge projected with different velocity normal to electric field experience same force (R ): A charged particle experiences force, independent of velocity in electric field

State basic properties of em. Waves.

One face of a prism with a refracting angle of 30^@ is coated with silver. A ray incident on another face at an angle of 45^@ is refracted and reflected from the silver coated face and retraces its path. What is the refractive index of the prism?

The hysterisis loop of material depends not only on the nature of material but also on the history of its magnetization cycles. Suggest a use of this property of material.

Referring to the provious illustration, if the maximum heights for two possible paths are given as H_(1)=3m and H_(2)=9m, find the corresponding angles of projection

Suppose that the same system of charges is now placed in an external electric field E=A(1//r^2),A=9xx10^5Cm^-2. What would the electros -tatic energy of the configuration be ?

Magnetic intensity is measured in

Name the device which results in the amplification of signals.

The coils, in certain galvanometers, have a fixed core made of a non-magnetic metallic material. Why does the oscillatory coil come to rest so quickly in such a core ?

Assertion:For a perfectly diamagnetic substance permeability is always one. Reason: The ability of a material of permit the passage of magnetic lines of force through it is called magnetic permeability.

A straight rod of light L and mass m is pivoted freely from a point of the roof. Its lower end is connected to an ideal spring of spring constant K. The other end of the spring is connected to the wall as shown in the figure. Find the frequency of small oscillation of the system.

If the conjugatefoci of a spherical mirror lie of the same side of the mirror then, what is the nature of the mirror?

In a arrangement of Young experiment the central fringe of interference pattern produced by light of wavelength 6000 Å so the central fringe is superposing to 4th order dark fringe, after a glass plate of refractive index 1.5 is introduced. The thickness of the glass plate would be ......

A rod of 5 cm length is moving perpendicular to uniform magnetic field of intensity 2 xx 10^(-4) "Wbm"^(-2). If the acceleration of rod is 2 ms^(-2), the rate of increasing of the induced emf is .......

A metal rod of Young's modulus Y and coefficient of thermal expansion a is held at its two ends such that its length remains invariant. If its temperature is raised by t^(@)C, the linear stress developed in it is:

Consider sunlightincident on a slit of width 10^(4)A^(0). The image seen through the slit shall :

When a thin wedge-shaped film is illuminated by a parallel beam of light of wavelength 6000 overset()A, 7 fringes are observed in a certain region of the film. How many fringes will be observed in the same region of the film if light of wavelength 4200 overset()A is used ?