40048 + Interview Questions in Physics in Class 11

1.	The function (sin^(2) omegat) represents
Answer» A periodic but not SIMPLE harmonic MOTION A simple harmonic motion with a period `(2pi)/(omega)` A simple harmonic motion with a period half that of `cos omega t` A simple harmonic motion with a period TWICE that of `cos omegat` Answer :C

Discussion

2.	When is the magnitude of (A+B) equal to the magnitude of (A-B)?
Answer» SOLUTION :When A is PERPENDICULAR to B.

Discussion

3.	An athlete throws a discus from rest to a final angular velocity of 15 rad s^(-1) in 0.270 s before releasing it. During acceleration, discus moves in a circular arc of radius 0.810 m. Acceleration of discus before it is released is
Answer» `45 m s^(-2)` `182 m s^(-2)` `187 m s^(-2)` `192 m s ^(-2)` Solution :`omega = omega_(0) + alpha t or omega = 0 + alpha t` or `alpha = (omega)/(t) = (15)/(0.270) rad s^(-2)` `THEREFORE a = R alpha = 0.81 XX (15)/(0.270) = 45ms^(-2)`

Discussion

4.	Moment of force is a vector ___true or false ?
Answer» ANSWER :TRUE

Discussion

5.	If velocity of centre of mass v_(cm)=0 and angular speed omega=0, then object is said to be in …... equilibrium.
Answer» ANSWER :STATIC

Discussion

6.	The step-ladder shown in figure 6.11 is 8 m long and hinged at C.BDis a tie rod 2.5 m long half way up. A man of 86 kg climbs 6 m along the ladder . Find the tension in the tie rod the forces exerted on the ladder by the assuming the floor to frictionless and the ladder weightless. [Hints: Consider the free-body diagram of the sides of the ladder.]
Answer» ANSWER :`R_(A)=54.0 KGF, R_(E)=32.2 kgf, T=21.2 KG `

Discussion

7.	The range of a projectile fired at angle of 15^(@) is 40m . If it is fired with the same speed at an angle of 45^(@)then, which one of the following statement is an incorrect statement ?
Answer» FINAL range is twice the initial range. Final range is half of the initial range. Final range is greater then the initial range Final range is 80 m Solution :`R = (u^(2) sin 2 THETA)/(2)` `R prop sin 2theta` `(R')/(R) = (sin 2 (45))/(sin 2 (15)) = (sin 90)/(sin 30) = 2` (a) R' = 2R (b) `R' = 2xx 40 = 80 m ` (c) `R ' gt R` `:.` Option (b) is INCORRECT statement

Discussion

8.	Themoon is observed from two diametrically opposite points A and B on Earth. The angle theta subtended at the moon by the two directions of observation is 1^(@)54' . Given the diameter of the Earth to be about 1.276xx10^(7) , compute the distance of the moon from the Earth.
Answer» SOLUTION :We have `theta = 1^(@)54. =114. = (114xx60)"xx(4.85xx10^(-6))` rad =`3.32xx10^(-2)` rad, Since `1" = 4.85xx10^(-6)` rad, Also b=AB=`1.276xx10^(7)m` Hence from Eq. (2.1.) , we have the earth-moon DISTANCE. D=b/`theta` `=(1.276xx10^(7))/(3.32xx10^(-2))` `=3.84xx10^(8)m`

Discussion

9.	Which are inferior planets ?
Answer» SOLUTION :Planets which at less distance between the SUN and the Earth are CALLED inferior planets.

Discussion

10.	A body travels a distance of (13.8+0.2)m uniformly in a time (4.0+0.3) sec. The velocity of the body in ms^(-1) is
Answer» `(3.45pm 0.2)` `(3.45pm0.3)` `(3.45pm0.2)` `(3.45pm0.5)` ANSWER :B

Discussion

11.	The terminal velocity of a copper ball of radius 1.0 mm falling through a tank of oil at 20^(@)C is 8.5cms^(-1) .Compute the viscosity of the oil at 20^(@)C .Density of oil is 1.5xx10^(3)kgm^(-3) , density of copper is 8.9xx10^(3)kgm^(-3)
Answer» SOLUTION :RADIUS of COPPER ball , `r=2.0mm=2xx10^(-3)m` The TERMINAL velocity of ball , `v_(t)=6.5cms^(-1)=6.5xx10^(-2)ms^(-1)` Density of oil `sigma=1.5xx10^(3)kgm^(-3)` Density of copper `rho=8.9xx10^(3)kgm^(-3)` From Stoke.s law , `eta=(2)/(9)xx(r^(2)g)/(v_(t))(rho-sigma)` `=(2xx(2xx10^(-3))^(2)xx9.8(8.9xx10^(3)-1.5xx10^(3)))/(9xx6.5xx10^(-2))` `=9.917xx10^(-6+3+2)` `=9.9xx10^(-1)` `=0.99kgm^(9-1)s^(-1)`

Discussion

12.	According to Newton.s law of cooling (provided the difference of temperature is small) the rate of loss of heat is proportional is
Answer» the EXCESS temperature the SQUARE of the excess temperature the cube of the excess temperature the fourth POWER of the excess temperature ANSWER :A

Discussion

13.	Assertion : In a freely falling liquid container, upthrust force is zero. Reason : In freely falling case value of effective value of g is zero.
Answer» If both ASSERTION and Reason are correct and Reason is the correct EXPLANATION of Assertion. If both Assertion and Reason are true but Reason is not the correct explanation of Assertion. If Assertion is true but Reason is FALSE. If Assertion is false but Reason is true. Solution :upthrust =mass of fluid displaced `xx g_("effective")` And in case of free FALL, `g_("effective")=0`

Discussion

14.	(A) : When air is blown between two ping pong balls which are suspended freely they move closer (R ) : When air is blown between two ping pong balls the pressure between the balls decreases
Answer» Both (A) and (R ) are true and (R ) is the correct EXPLANATION of (A) Both (A) and (R ) are true and (R ) is not the correct explanation of (A) (A) is true but (R ) is false Both (A) and (R ) are false ANSWER :A

Discussion

15.	Let us consider that our galaxy consists of 2.5 xx 10^11 stars each of one solar mass. How long will a star at a distance of 50,000 ly from thegalactic centre take to complete one revolution ? Take the diameter of the milky way to be 10^5 ly .G = 6.67 xx 10^(-11) Nm^2 Kg^2
Answer» SOLUTION :`M = 2.5 XX 10^11 `solar mass ` = 2.5 xx 10^11 xx (2 xx 10^30 )kg= 5.0 xx 10^41 kg ` We know that `M = (4pi^2 R^3)/(GT^2) ` ` r = 50,000ly = 50,000 xx 9.46 xx 10^15 m = 4.73 xx 10^20m` ` T = ((4pi^2 r^3)/(GM))^(1//2) = [(4 xx (22//7)^2 xx (4.73 xx 10^20)^3)/((6.67 xx 10^(-11)) xx (5.0 xx 10^41))]^(1/2) = 1.12 xx 10^16 s `

Discussion

16.	For a linear SHM, when the distance of the oscillator from the equilibrium position has values y_(1)" and "y_(2) the velocities are v_(1)" and "v_(2). Show that the time period of oscillation is T= 2pi [(y_(2)^(2) -y_(1)^(2))/(v_(1)^(2)-v_(2)^(2))]^(1/2).
Answer» Solution :Velocity `v_(1)` at displacement `y_(1)` is `v_(1) = OMEGA SQRT(A^(2) - y_(1)^(2))"""……."(1)` and velocity `v_(2)` at displacement `y_(2)` is `v_(2) = omegasqrt(A^(2) - y_(2)^(2))""".........."(2)` `therefore v_(1)^(2) -v_(2)^(2) = omega^(2)[A^(2) -y_(1)^(2) - A^(2)+ y_(2)^(2)]` `= omega^(2) [ y_(2)^(2)- y_(1)^(2)]` `therefore omega^(2)= (v_(1)^(2)- v_(2)^(2))/(y_(2)^(2)- y_(1)^(2))` `therefore omega = [(v_(1)^(2)- v_(2)^(2))/(y_(2)^(2)- y_(1)^(2))]^(1/2)` `therefore (2pi)/(T) = [(v_(1)^(2)- v_(2)^(2))/(y_(2)^(2)- y_(1)^(2))]^(1/2)` `therefore T =2pi[(v_(1)^(2)- v_(2)^(2))/(y_(2)^(2)- y_(1)^(2))]^(1/2)` is PROVED.

Discussion

17.	Define angular momentum. Give an expression for it.
Answer» Solution :The angular momentum of a point MASS is DEFINED as the moment of its linear momentum `vecL= VECR xx vecp ORL= RP sin theta`

Discussion

18.	A hollow sphere of inner radius a and outer radius 2a is made of a material of thermal conductivity K. It is surrouunded by another hollow sphere of inner radius 2a and outside radius 3a made of same material of thermal conductivity K. The inside of smaller sphere is maintained at 0^(0)C and the outside of bigger sphere at 100^(0)C. The system is in steady state. The temperature of the interface is 25xx x. Then x is equal to ....................
Answer» ANSWER :3

Discussion

19.	Considerthe decay of a free neutron at rest : n to p +e^(-) Show that the two body decay of this type must necessary give an electron of fixed energy and therefore cannot account distribution in the beta - decay of a neutron or a nucleous as shown in figure. [ Note : The simple result of this exercise was one among the several arguments advancedbyW . Pauli to perdict the existence of a thirdparticle in the decay products of beta -decay . This particleis known as neutrino spin 1/2( like e^(-) p or n ) but is neutral ad either massless or having an extremely small mass (compared to the mass of electron) and which interacts very weakly with matter . The correct decay process of neutron is : n to p+e(-)+v)
Answer» Solution :Suppose `Deltam` is USED for a decay of neutron to a proton and electron energy released is E . but `E = Deltamc^(2)` where `Deltam + "mass of neutron "-("mass of proton "+ " mass of electron")` `= 1.6747 xx10^(-24) - (1.6724 xx10^(-24)+9.11 xx10^(-28))` ` = 1.6747 xx10^(-24) -1.6733 xx10^(-24)` ` = 0.0014 xx10^(-24)`fram Now , `E = Deltamc^(2)` `= 0.0014 xx10^(-24) xx(3xx10^(-10))^(2)` ` = 0.0126 xx10^(-4)` erg ` =(0.0126 xx10^(-4))/(1.6 xx10^(-12))eV` `= 0.007875 xx 10^(8)` eV ` = 0.7875 xx10^(6) ` eV ` = 0.79` MeV Mass of a electron and a positionis same and charges are also same but they are opposite. When the electron and a positron comes to CLOSE they destroyed each other and their mass converted into energy as according to Einstein relation and the energy in the form of gamma rays produced . `E=2mc^(2) = 2xx9.1 xx10^(-31) xx(3xx10^(8))^(2)` ` = 1.638 xx 1^(-13)J ` ` =(1.638 xx10^(-13))/(1.6xx10^(-19))`MeV Photon must have minimum energy for PAIR production .

Discussion

20.	Water in a bucket tied with rope whirled around in a vertical circle of radius 0.5 m. Calculate the minimum velocity at the lowest point so that the water does not spill from it in the course of motion. (g=10ms^(-1))
Answer» `sqrt5 ms^(-1)` `5 ms^(-1)` `50 ms^(-1)` `500 ms^(-1)` SOLUTION :Required speed at the HIGHEST point`=sqrt(RG) =sqrt(0.5xx10) = sqrt5 ms^(-1)`

Discussion

21.	Two identical bodies of same mass are raised to same heights by two persons X and Y in 10s and 20s respectively. The work done by
Answer» X is greater Y is greater both X and Y are the same none Answer :C

Discussion

22.	A body starts with a velocity 2hati+3hatj+11hatkm//s and moves with an acceleration 10hati+10hatj+10hatk m//s^(2). What is its velocity after 0.2seconds?
Answer» ANSWER :`4hati+5hatj-9hatk`

Discussion

23.	Differentiate between closed pipe and open pipe at both ends of same length fro frequency of fundamental note and harmonics.
Answer» SOLUTION :(i) In a PIPE open at both ends, the frequency of fundamental note PRODUCED is twice as that produced by a closed pipe of same length.(ii) An open pipe produces all the HARMONICS, while in a closed pipe, the even harmonics are ABSENT.

Discussion

24.	If I_(1), I_(2) and I are moments of inertia of a disc about its geometric axis, diameter and a tangent in its plane, then
Answer» `I_(1) GT I_(2) gt I_(3)` `I_(3) gt I_(2) gt I_(1)` `I_(3) gt I_(1) gt I_(2)` `I_(2) gt I_(1) gt I_(3)` ANSWER :C

Discussion

25.	An ideal gas is taken through a cyclic thermodynamic process through four steps. The amounts of heat involved in these steps are Q_(1) = 5960 J, Q_(2) = -5585 J, Q_(3) = -2980 J and Q_(A)=3635J respectively. The corresponding works involved are w_(1) = 2200 J, W_(2) = -825 J, W_(3) =-1100 J, and W_(4)respectively (i) Find the value of W, (ii) What is the efficiency of the cycle ?
Answer» Solution :In a cyclic process `dU=0` Net heat absorbed by the system, `Q=Q_(1)+Q_(2)+Q_(3)+Q_(4)` `=5960-5585-2980+3645=1040J` Net work done `W=W_(1)+W_(2)+W_(3)+W_(4)` `=2200-825-1100+W_(4)=275+W_(4)` From 1ST law of thermodynamics, `Q=dU+W or 1040=0+275 +W_(4)` `:.W_(4)=1040 -275 =765J` EFFICIENCY of CYCLE `=("Work done (W)")/("Heat absorved"(Q_(1)+Q_(4)))` `=(275+765)/(5960+3645)=(1040)/(9605)` % efficiency `=(1040)/(9605)xx100=10.83%`

Discussion

26.	A 160 g rope 4 m long is fixed at one end and tied to a light string of the same length at the other end. Its tension is 400 N. (a) What are the wavelength of the fundamental and the first two overtones? (b) What are the frequencies of these standing waves? [Hint :In this case, fixed end is a node and the end tied with the light string is antinode.]
Answer» SOLUTION :(a) `l = lambda_(1)//4` `:. lambda_(1) = 4l = 16M,l= (3lambda_(2))//4` `:. lambda_2 = (4l)/3 = 5.33m` `l = 5lambda_(3)//4` `:. lambda_3 = (4l)/5 = 3.2m ` (b) `v= sqrt (T/mu)` `= sqrt(400/(0.16//4)) = 100 m//s` Now, `f_1 = v/lambda_1 = 100/16 = 6.25 Hz` Similarly, `f_2` and `f_3`.

Discussion

27.	If frequency (F), velocity (v) and density (D) are considered as fundamental units the dimensional formula for momentum will be.....
Answer» `D^(2)v^(2)F^(2)` `D^(1)v^(4)F^(-3)` `D^(-1)v^(-4)F^(-3)` `D^(1)v^(1)F^(-2)` Solution :`P prop F^(a)v^(b)D^(c)` `:.P=KF^(a)v^(b)D^(c)` where `K ne 0` dimensionless onstant. `:. A,b ne0 and a,b,c, in R` Comparing both the SIDES `:. M^(1)L^(1)T^(1)=(T^(-1))^(a)(L^(1)T^(-1))^(b)(M^(1)L^(-3))^(c)` `=T^(-a)XXL^(b)xxM^(c)L^(-3c)` `=M^(-c)xxL^(b-3c)T^(-a-b)` `:.` Comparing power of M,L,T `:. 1=c "" :. c=I` `:. 1=b-3c=b-3 "" :.b=4` `:. a=1-b=1-4=-3 "" :.a=-3` `:.` Dimensional formula of momentum in new SYSTEM is `P=K F^(a)v^(b)D^(c)` `K=1, a=-3,b=4,c=1` `:.[P]=F^(-3)v^(4)D^(1)` `:.[P]=D^(1)v^(4)F^(-3)`

Discussion

28.	It is easier to catch a tennis balll as compared to a cricket ball, moving with the same velocity. This is because
Answer» The tennis BALLL is lighter than the cricket ball the linear momentum of the tennis ball is less than that of the cricket ball the potential energy of the tennis ball is more than that of the cricket ball both the balls have the same kinetic energy Solution :Mass(m) of the tennis ball LT Mass (M) of the cricket ball as they have the same velocity. p of tennis ball lt p of cricket ball. Hence the IMPACT of tennis ball on the HAND is less.

Discussion

29.	What is error of measurement ?
Answer» SOLUTION :It is the DIFFERENCE in the TRUE value and measured value of a QUANTITY.

Discussion

30.	Assertion: The earth is slowing down and as a result the moon is coming nearer to it.Reason:The angular momentum of the earth moon system is not conserved.Which one of the following statements is a correct staement?
Answer» Both assertion and reason are TRUE and reason explains assertion correctly. Both assertion and reason are true but reason does not EXPLAIN assertion correctly. Both assertion and reason are false. Assertion is true but reason is false. Solution :The earth is not SLOWING down. The angular MOMENTUM of the earth moon SYSTEM is conserved.

Discussion

31.	The speed of a wave in a certain medium is 900 m/s. If 3000 waves passes over a certain point of the medium in 2 minutes, then compute its wavelength.
Answer» Solution :Speed of the wave in medium `v= 900 ms^(-1)` frequency (N) `=("Number of waves")/("TIME")=(3000)/(2 xx 60) = 25 s^(-1)` Wavelength `lambda = v/n = (9000)/(25) , lambda =36 m`

Discussion

32.	An explosion breaks a rock into three parts in a horizontal plane. Two of them go off at right angles to each other. The first part of mass 1 kg moves with a speed of 12 ms^(-1)and the second part of mass 2 kg moves with 8 ms^(-1)speed. If the third part flies off with 4 ms^(-1)speed, then its mass i s .....
Answer» 17 kg 3 kg 5 kg 7 kg Solution : Supposemass of rockis M andvelocity`vec( V )= 0 ` massof firstpiece`m_(1) = 1` kgandvelocity`vec( v) _(1) = 12 hat(I ) m//s` Mass of thirpiece`m_(3)=?`andmagnitude ofvelocity`v_(3) =4 m//s` From the lawof conservationof momentum Momentum ofrock= addition of momentum Magnitude`m_(3) v_(3) = SQRT((12)^(2) + (16)^(2))` `=sqrt(144+256)` `=sqrt(400) =20 KGMS^(-1)` `m_(3)= (20)/(v_(3) ) = (20)/(4) =5 kg`

Discussion

33.	Motion of an oscillating liquid column in a U-tube is
Answer» periodic but not simple harmonic. non-periodic simple harmonic and time period is independent of the density of the LIQUID. simple harmonic and time period is directly proportional to the density of the liquid. Solution :Motion of an OSCILLATING liquid column in a U tube is SHM with period, `T=2pisqrt((H)/(G))`, where h is the height of liquid column in one arm of U tube in equilibrium position of liquid. Therefore, T is independent of density of liquid.

Discussion

34.	A particle execute S.H.M from the mean position. Its amplitude is A, its time period is 'T'. At what displacement, will its speed be half of its maximum speed ?
Answer» `(SQRT(3)A)/(2)` `(sqrt(2)A)/(3)` `(2A)/(sqrt(3))` `(3A)/(sqrt(2))` Answer :A

Discussion

35.	Einstein was awarded Noble Prize in Physics for
Answer» THEORY of RELATIVITY LAW of GRAVITATION Uncerainty Principle Photo electricity Answer :(d)

Discussion

36.	A block of 0.5kg is placed on a horizontal platform. The system is making vertical oscillations about a fixed point with a frequency of 0.5Hz. Find the maximum amplitude of oscillation if the block is not to lose contact with the horizontal platform ?
Answer» 0.6542 m 0.9927 m 0.7428 m 0.852 m ANSWER :B

Discussion

37.	The ratio gamma=(C_(P))/(C_(V)) for a gas mixture consisting of 8 g of helium and 16 g of oxygen is
Answer» `(23)/(15)` `(15)/(23)` `(27)/(11)` `(17)/(27)` Solution :Helium is a MONO atomic gas and oxygen is diatomic gas. `C_(P)= of O_(2)= (7)/(2) R,C_(P) "of helium"= (5)/(2)R,n_(1) "of oxygen"=2` `C_(V) of O_(2)= (5)/(2)R , C_(V) "of helium"= (3)/(2)R, n_(2) "of oxygen"=0.5` `gamma_("mix")= (n_(1)C_(P_(1))+ n_(2)C_(P_(2)))/(n_(1)C_(V_(1))+ n_(2)C_(V_(2)))= (2 xx (5)/(2)R+ (1)/(2) xx (7)/(2) R)/(2 xx(3)/(2)R+ (1)/(2) xx (5)(2)R)= (27)/(17)`

Discussion

38.	Find the magnitude of acceleration due to gravity at height of 10 km from the surface of earth.
Answer» Solution :`implies` In equation `g_h=g_e(1-(2H)/R_e),h = 10 KM = 10^(4)m` `Re = 6.4 XX 10^(6) m and g_e=9.8 ms^(-2)` `:. g_(h)=9.8 [1-(2XX10^(4))/(6.4xx10^(6))]` `:. g_h=9.8[1-0.003125]` `:. g_h= 9.8 [0.996875]` `:. g_h=9.769375 ms^(-2)` `:. g_h = 9.8 ms^(-2)`

Discussion

39.	An air bubble of radius 1cm rises from the bottom portion through a liquid of density 1.5g/cc at constant speed of 0.25cm/sec. If the density of air is neglected then find the coefficient of viscosity of the liquid.
Answer» SOLUTION :130 PA. s

Discussion

40.	A motion of a shell fired from the gun is an example for . . . . . Dimensional motion.
Answer» two three one both (a) and (B) SOLUTION :It TAKES PLACE in a PLANE.

Discussion

41.	What is the effet of radial and tangential components of linear acceleration in circular motion?
Answer» Solution :Due to RADIAL component, the DIRECTION of linear velocity of PARTICLE is CHANGES which due to tangential component. The magnitude of linear velocity of particle changes.

Discussion

42.	If theta is the angle between unit vectors vec(A) and vec(B), then ((1-vec(A).vec(B)))/((1+vec(A).vec(B))) is equal to
Answer» `TAN^(2)(theta//2)` `SIN^(2)(theta//2)` `cot^(2)(theta//2)` `cos^(2)(theta//2)` ANSWER :A

Discussion

43.	Least cound of metre scale is :
Answer» 1 cm 0.1 cm 1 mm 0.1 mm Solution :`"L.C"=(1)/(1000)m=10^(-3)m=1mm`

Discussion

44.	Pressure versus temperature graph of an ideal gas is as shown in figure. Density of the gas at point A is rho_0 . Density at point B will be____
Answer» `3/4rho_0` `3/2rho_0` `4/3rho_0` `2rho_0` Solution :`RHO="PM"/"RT"` or `rho PROP P/T` `THEREFORE (P/T)_A=P_0/T_0` and `(P/T)_B=3/2 (P_0/T_0)` `therefore (P/T)_B=3/2(P/T)_A` `therefore rho_B=3/2rho_A=3/2rho_0`

Discussion

45.	Rotational analogue of inertia in translatory motion is
Answer» mass weight moment of incrtia Torque Answer :C

Discussion

46.	Two men each of mass m stand on the rim of a horizontal circular disc, diametrically opposite to each other. The disc has a mass M and is free to rotate about a vertical axis passing through its centre of mass. Each man start simultaneously along the rim clockwise and reaches their original starting points on the disc. The angle turned through by the disc with respect to the ground (in radian) is:
Answer» `(8mpi)/(4m+M)` `(2mpi)/(4m+M)` `(MPI)/(M+m)` `(4mpi)/(2M+m)` ANSWER :A

Discussion

47.	Law of equipartition of energy is used to
Answer» predict the specific heats of GASES predict the specific heats of SOLIDS both 1 and 2 are correct both 1 and 2 are INCORRECT Answer :C

Discussion

48.	An airplane pilot wants to fly from city A to city B which is 1000 km duenorthof city A. The speed of the plane in still air is 500 km/hr. The pilot neglects the effect of the wind and directs his planedue north and 2 hours later find himself 300 km due north-east of city B. The wind velocity is
Answer» 150 km/hr at `45^(@)` N of E 106 km/hr at `45^(@)` N of E 150 km/hr at `45^(@)` N of W 106 km/hr at `45^(@)` N of W Answer :A

Discussion

49.	Two particles of masses 3kg and 2kg move due north and due east respectively with the velocities2ms^(-1) and 3ms^(-1). The magnitude and direction of the velocity of centre of mass is
Answer» 1.2 NE `SQRT(2)NE` 2SW `1.2 sqrt(2)NE` ANSWER :D

Discussion

50.	Give distance between consecutive nodes and antinodes in terms of wavelength.
Answer» `lamda` `(lamda)/(2)` `(lamda)/(4)` `2lamda` Solution :DISTANCE of `n^(th)` node from `X =0` is `x _(N) = (nlamda)/(2)` Distance of `n^(th)` ANTINODE from `x =0` is, `x _(A) = (n + (1)/(2)) (lamda)/(2)` REQUIRED distance is, `x _(A) - x _(N) = (n + (1)/(2)) (lamda )/(2) - (n lamda )/( 2)` `therefore x_(A) - x _(N) = (lamda )/(4)`

Discussion

Explore topic-wise InterviewSolutions in Current Affairs.

The function (sin^(2) omegat) represents

When is the magnitude of (A+B) equal to the magnitude of (A-B)?

An athlete throws a discus from rest to a final angular velocity of 15 rad s^(-1) in 0.270 s before releasing it. During acceleration, discus moves in a circular arc of radius 0.810 m. Acceleration of discus before it is released is

Moment of force is a vector ___true or false ?

If velocity of centre of mass v_(cm)=0 and angular speed omega=0, then object is said to be in …... equilibrium.

The range of a projectile fired at angle of 15^(@) is 40m . If it is fired with the same speed at an angle of 45^(@)then, which one of the following statement is an incorrect statement ?

Themoon is observed from two diametrically opposite points A and B on Earth. The angle theta subtended at the moon by the two directions of observation is 1^(@)54' . Given the diameter of the Earth to be about 1.276xx10^(7) , compute the distance of the moon from the Earth.

Which are inferior planets ?

A body travels a distance of (13.8+0.2)m uniformly in a time (4.0+0.3) sec. The velocity of the body in ms^(-1) is

The terminal velocity of a copper ball of radius 1.0 mm falling through a tank of oil at 20^(@)C is 8.5cms^(-1) .Compute the viscosity of the oil at 20^(@)C .Density of oil is 1.5xx10^(3)kgm^(-3) , density of copper is 8.9xx10^(3)kgm^(-3)

According to Newton.s law of cooling (provided the difference of temperature is small) the rate of loss of heat is proportional is

Assertion : In a freely falling liquid container, upthrust force is zero. Reason : In freely falling case value of effective value of g is zero.

(A) : When air is blown between two ping pong balls which are suspended freely they move closer (R ) : When air is blown between two ping pong balls the pressure between the balls decreases

Let us consider that our galaxy consists of 2.5 xx 10^11 stars each of one solar mass. How long will a star at a distance of 50,000 ly from thegalactic centre take to complete one revolution ? Take the diameter of the milky way to be 10^5 ly .G = 6.67 xx 10^(-11) Nm^2 Kg^2

For a linear SHM, when the distance of the oscillator from the equilibrium position has values y_(1)" and "y_(2) the velocities are v_(1)" and "v_(2). Show that the time period of oscillation is T= 2pi [(y_(2)^(2) -y_(1)^(2))/(v_(1)^(2)-v_(2)^(2))]^(1/2).

Define angular momentum. Give an expression for it.

Water in a bucket tied with rope whirled around in a vertical circle of radius 0.5 m. Calculate the minimum velocity at the lowest point so that the water does not spill from it in the course of motion. (g=10ms^(-1))

Two identical bodies of same mass are raised to same heights by two persons X and Y in 10s and 20s respectively. The work done by

A body starts with a velocity 2hati+3hatj+11hatkm//s and moves with an acceleration 10hati+10hatj+10hatk m//s^(2). What is its velocity after 0.2seconds?

Differentiate between closed pipe and open pipe at both ends of same length fro frequency of fundamental note and harmonics.

If I_(1), I_(2) and I are moments of inertia of a disc about its geometric axis, diameter and a tangent in its plane, then

If frequency (F), velocity (v) and density (D) are considered as fundamental units the dimensional formula for momentum will be.....

It is easier to catch a tennis balll as compared to a cricket ball, moving with the same velocity. This is because

What is error of measurement ?

Assertion: The earth is slowing down and as a result the moon is coming nearer to it.Reason:The angular momentum of the earth moon system is not conserved.Which one of the following statements is a correct staement?

The speed of a wave in a certain medium is 900 m/s. If 3000 waves passes over a certain point of the medium in 2 minutes, then compute its wavelength.

Motion of an oscillating liquid column in a U-tube is

A particle execute S.H.M from the mean position. Its amplitude is A, its time period is 'T'. At what displacement, will its speed be half of its maximum speed ?

Einstein was awarded Noble Prize in Physics for

A block of 0.5kg is placed on a horizontal platform. The system is making vertical oscillations about a fixed point with a frequency of 0.5Hz. Find the maximum amplitude of oscillation if the block is not to lose contact with the horizontal platform ?

The ratio gamma=(C_(P))/(C_(V)) for a gas mixture consisting of 8 g of helium and 16 g of oxygen is

Find the magnitude of acceleration due to gravity at height of 10 km from the surface of earth.

An air bubble of radius 1cm rises from the bottom portion through a liquid of density 1.5g/cc at constant speed of 0.25cm/sec. If the density of air is neglected then find the coefficient of viscosity of the liquid.

A motion of a shell fired from the gun is an example for . . . . . Dimensional motion.

What is the effet of radial and tangential components of linear acceleration in circular motion?

If theta is the angle between unit vectors vec(A) and vec(B), then ((1-vec(A).vec(B)))/((1+vec(A).vec(B))) is equal to

Least cound of metre scale is :

Pressure versus temperature graph of an ideal gas is as shown in figure. Density of the gas at point A is rho_0 . Density at point B will be____

Rotational analogue of inertia in translatory motion is

Law of equipartition of energy is used to

An airplane pilot wants to fly from city A to city B which is 1000 km duenorthof city A. The speed of the plane in still air is 500 km/hr. The pilot neglects the effect of the wind and directs his planedue north and 2 hours later find himself 300 km due north-east of city B. The wind velocity is

Two particles of masses 3kg and 2kg move due north and due east respectively with the velocities2ms^(-1) and 3ms^(-1). The magnitude and direction of the velocity of centre of mass is

Give distance between consecutive nodes and antinodes in terms of wavelength.