40048 + Interview Questions in Physics in Class 11

1.	A wooden cylinder of length L is partly submerged in a liquid of specific gravity rho_(1) with n^(th)(n lt 1)part of it inside the liquid. Another immiscible liquid of ensity rho_(2). is poured to completely submerge the cylinder. Density of cylinder rho is the square root of the product of densities of two liquids When the cylinder is slightly depressed and released, it oscillates. Let there be a mean position Find the time period of small oscillations below the mean position
Answer» `PI[((N+1)L)/(g(n-1))]^(1//2)` `pi[(n^(2)L)/(g(1-n)^(2))]^(1//2)` `pi[(nL)/(g(n^(2)-1))]^(1//2)` Answer :D

Discussion

2.	When the gas from a cooking gas cylinder is used or when a gas stove is lighted what happens to the pressure of the gas in the cylinder?
Answer» Solution :Pressure DECREASES when a GAS cylinder is used for cooking some amount of gas comes out by keeping VOLUME as CONSTANT. Pressure of gas is proportional to mass of gas in the container `P propto m` (when V & T are constant) So pressure in the cylinder decreases.

Discussion

3.	The ratio of radii of two cylindrical rods of same material is 2 : 1 and ratio of their lengths is 2 : 3. Their ends are maintained at same temperature difference. If rate of flow of heat in the longer rod is 2 Cal s^(-1), then that in the shorter rod will be
Answer» `4" Cal s"^(-1)` `12" Cal s"^(-1)` `8" Cal s"^(-1)` `1" Cal s"^(-1)` ANSWER :B

Discussion

4.	One radian is the angle subtended at …………. By an arc ……………… .
Answer» ANSWER :the CENTRE of a CIRCLE ; equal in length to the RADIUS of the circle.

Discussion

5.	Calculate the root mean square velocity of a gas of density 1.5 g "litre "^(-1) at a pressure of 2xx10^6 Nm^(-2) .
Answer» Solution :`rho=1.5g "LITRE"^(-1) = 1.5 "kgm"^(-3)`, `P = 2 xx10^6 Nm^(-2)` `v_(rms)=SQRT((3P)/rho)` `=sqrt((3xx2xx10^6)/(1.5))=2xx10^3 ms^(-1)`

Discussion

6.	The wavelength of radiation emitted by a black body depends on
Answer» NATURE of the surface temperature surface area all of these Answer :B

Discussion

7.	What is moment of inertia in terms of angular momentum (L) and kinetic energy (K)?
Answer» `(L)/(2K)` `(L^(2))/(2K)` `(L)/(2K^(2))` `(L^(2))/(K)` SOLUTION :Kinetic energy `K=(1)/(2)Iomega^(2)` `=(I^(2)omega^(2))/(2I)` `=(L^(2))/(2I)` `therefore I=(L^(2))/(2K)`

Discussion

8.	A block of mass 10 kg is moving in x-direction with a constant speed of 10 m s^(-1). It is subjected to a retarding force F=-0.1.x J m^(-1) during its travel from x = 20 m to x = 30 m. Its final kinetic energy will be
Answer» 25 J 50 J 75 J 100 J ANSWER :A

Discussion

9.	The density of a wire used in the experiment is 6.9 xx 10^(3) kg//m^(3). If a stress of 2.5 xx 10^(8) N//m^(2) is given to the wire, determine the speed of transverse wave in the wire.
Answer» Solution :Given, `RHO = 6.9 xx 10^(3) kg//m^(3)` Stress `= 2.5 xx 10^(8) N//m^(2)` If A is the area of cross SECTION of the WIRE, then tension in the wire T = Stress `xx` area `= (2.5 xx 10^(8) xx A)N` Mass per unit LENGTH is `m = A xx 1 xx rho = A xx 6.9 xx 10^(3) kg//m^(3)` `therefore` Speed of transverse wave. `upsilon = sqrt((T)/(m)) = sqrt((2.5 xx 10^(8) xx A)/(A xx 6.9 xx 10^(3)))` = 190.3 m/s

Discussion

10.	in a Bramha's press the area of the two plungers are 2cm^(2) and 60 cm^(2) respectively. The pump plunger is worked by a lever whose arms are 5 cm and 75 cm. if the end of the lever is raised and lowered by 30 cm at evergy stoke, find the numberof strokes required to raise the press plunger by 2cm .
Answer» ANSWER :637.5 KG

Discussion

11.	A body is projected up along an inclined plane from the bottom with speed V_(1). If it reaches the bottom of the plane with a velocity V_(1) find (v _(1)//v_(2)) if theta is the angle of inclination with the horizontal and mube the co-efficient of friction.
Answer» `(sin THETA + MU COS theta)/(sin theta - mu cos theta)` `SQRT((sin theta + mu cos theta)/( sin theta - mu cos theta))` `(cos theta + mu sin theta)/( cos theta - mu sin theta)` `sqrt (( cos theta + mu sin theta)/(cos theta - mu sin theta))` Answer :B

Discussion

12.	A geyser heats water flowing at the rate of 3.0 litres per minute from 27 °C to 77 °C. If the geyser operates on a gas burner, what is the rate of consumption of the fuel if its heat of combustion is 4.0 × 104 J//g ?
Answer» 16 G 4 g 0.3 g 0.16 g ANSWER :A

Discussion

13.	When a body is projected with a velocity greater than the orbital velocity but less than escape velocity how does it move ?
Answer» SOLUTION :It MOVES in an ELLIPTICAL ORBIT.

Discussion

14.	A body projected vertically with a velocity 'u' from ground. Its velocity
Answer» a and B correct b is correct c and d correct a is correct Answer :C

Discussion

15.	A piece of metal floats on mercury. The coefficient of expansion of the metal and mercury are Y _(1)and Y_(2) respectively. If the temperature of both mercury and metal are increased by DeltaT, by what factor does the fraction of the volume of the metal submerged in mercury change ?
Answer» Solution :Let the toal volume of metal in air and mercury `V and V _(3)` respectivley, `rho and sigma ` be the densities of metal and mercury RESPECTIVELY . When the metla flots in equilibrium, Fraction of the volume submerged, `f _(s) = (V _(s))/( V) = (rho )/(sigma ) .....(1)` When te temperature charges, the fractionof volume submerged changes as densitied change. `(Delta f _(s))/( f _(s)) = (f _(s))/(f _(s)) - = (rho ^(1))/( sigma ^(2)) xx (sigma )/( rho ) -1""...(2)` DENSITY of LIQUID DECREASES as temperature increases `implies rho . = ( rho )/(1 + gamma Delta T .) , sigma . = (sigma )/(1 + gamma _(2) Delta T)` which on subsituation in EQN. yields `(Delta f _(s))/( f _(s)) = (1 + gamma _(2) Delta T)/( 1 + gamma _(1) Delta T) -1 = ((1 + gamma _(2) Delta T ) - (1 + gamma _(l) Delta T ))/((1 + gamma _(t ) Delta T)) = ((gamma _(2) - gamma _(1)) Delta T)/( (1 + gamma _(t) Delta T))` `= (gamma _(2) - gamma _(1)) Delta T (1 - gamma _(1) Delta T) = (gamma _(2) - gamma _(1)) Delta T` [As `(1)/( 1 + gamma _(t) Delta T) = (1 + gamma _(1) Delta T) ^(-1) = (1- gamma _(1) Delta T) ` and higher powers are neglected]

Discussion

16.	How is the gravitational force between two point masses affected when they are dipped in water keeping the separation between them the same?
Answer» SOLUTION :Since, `F = (Gm_(1) m_(2))/(r^(2))`, is independent of the nature of medium between two point masses `m_(1)` and `m_(2)`. Therefore, the GRAVITATIONAL force between two point masses will not be AFFECTED, when they are dipped in water.

Discussion

17.	n mole of an ideal gas undergo an isothernal process at temperature T. Further, P-V graph of the process is as shown in the figure. Tangent at point A, cuts the V-axis at point D. AO is the line joining the point A to the origin O of P-V diagram. Choose from following the correct option(s).
Answer» coordinates of point D is `((3V_(1))/(2),0)` coordinates of point D is `(2V_(1),0)` AREA of the TRIANGLE AOD is nRT area of the triangle AOD is `(3)/(4)` nRT Answer :B::C

Discussion

18.	Which one of the following is a null vector?
Answer» net DISPLACEMENT of a PARTICLE moving once AROUND, a circle velocity of a body projected VERTICALLY up, when the body is at the highest point acceleration of a particle executing S.H.M. at the mean position All the above Answer :D

Discussion

19.	Express 1 atm pressure into N//m^(2) and bar.
Answer» SOLUTION :1 atm `=1.013xx10^(5)N//m^(2)` `=1.013xx10^(5)Pa` `=1.013`bar

Discussion

20.	If the change in the value of g at a height h above the surface of the earth is same as at depth 'x' below the surface of the earth, then (h lt lt R)
Answer» X = h x = 2h `x = (h)/(2)` `x = h^(2)` ANSWER :D

Discussion

21.	A fully loaded Boeing aircraft has a mass of 3.3xx10^(5)kg, its total wing area is 500m^(2). It is in level flight with a speed of 960 km/h. (a) Estimate the pressure difference between the lower and upper surfaces of the wings (b) Estimate the fractional increase in the speed of the air on the upper surface of the wing relative to the lower surface. (The density of air is rho=1.2kgm^(-3))
Answer» Solution :(a) The weight of the Boeing aircraft is balanced by the upward force due to the pressure difference `DeltaPxxA=3.3xx10^(5)kgxx9.8` `DeltaP=(3.3xx10^(5)kgxx9.8ms^(-2))//500m^(2)` `=6.5xx10^(3)NM^(-2)` (b) We ignore the small height difference between the top and bottom sides in Eq. The pressure difference between them is then `Delta=(rho)/(2)(v_(2)^(2)-v_(1)^(2))` Where `v_(2)` is the speed of air over the upper surface and `v_(1)` is the speed under the bottom surface. `(v_(2)-v_(1))=(2Deltarho)/(rho(v_(2)+v_(1)))` Taking the average speed `v_(av)=(v_(2)+v_(1))//2=960km//h=267ms^(-1)`, we have `(v_(2)-v_(1))//v_(av)=(DeltaP)/(rhov_(av)^(2))~~0.08` The speed above the wing needs to be only 8% HIGHER than that below.

Discussion

22.	A uniform spherical shell rolls down a fixed inclined pla ne without sliping. Find the ratio of rotational kinetic energy to translational kinetic energy as is reaches lowest point of the incline.
Answer» Solution :As there is no SLIP `v=Romega` is valid and rotational kinetic energy `K_(R )=(1)/(2)I_(CM)OMEGA^(2)=(1)/(2)mk^(2)omega^(2)` and translational kinetic energy `K_(T)=(1)/(2)mv^(2)=(1)/(2)mR^(2)omega^(2)` THEREFORE `(K_(R ))/(K_(T))=(k^(2))/(R^(2))=(2)/(3)`

Discussion

23.	A train has to negotiate a curve of 40 m radius. What is the super elevation of the outer rail required for a speed of 54 kmh^(-1). The distance between the rails is one metre ?
Answer» SOLUTION :`h = V^(2)l//rg = -15^(2) XX 1//1 xx 9.8 = 0.574 m`

Discussion

24.	Average velocity of a particle executing SHM in one complete vibration is
Answer» zero `(A OMEGA)/(2)` `A omega` `(A omega^(2))/(2)` Solution :Displacement of S.H.O in one complete oscillation = 0 `:.` AVERAGE velocity `=("displacement")/("PERIODIC time") = (0)/(T) = 0`

Discussion

25.	In the arrangement shwon, initially both springs are in their natural length l_(0). The left spring has force constnat k_(0)=2N//m and the force constant of the right spring varies as k=k_(0)x, wherex is its compression. The mass of the block is 10/3 kg. At time t=0, the block is given a right ward velocity v_(0)=2 m/s. Both the springs are massless. When the block has moved through distance x_(0) m to the right, the elastic potential energy stored in the right spring is
Answer» `(2x_(0)^(3))/3J` `(x_(0)^(2))/2J` `(x_(0)^(3))/6J` `4/3x_(0)^(3)J` Answer :A

Discussion

26.	A ball is thrown in vertically upward direction. It returns back to the same position in 2s. Then the maximum height achieved by the ball is ...... (Take g = 9.8 ms^(-2))
Answer» `9.8m ` `14.7m` `4.9m` `19.6`m Solution :To REACH at maximum height a ball need t=1 s even at that POSITION v =0. From `v = v _(0) - g t, , v _(0) =g t` Now, SUPPOSE maximum height is h. `THEREFORE v ^(2) - v _(0) ^(2) = 2gh` ` therefore (0)^(2) - (g t) ^(2) = 2gh` `therefore h = ((g t ) ^(2))/( 2g ) = (g t ^(2))/( 2) = ( 9.8 xx (1)^(2))/( 2) = 4.9 m`

Discussion

27.	Sand is fallingon a conveyor belt at the rate of 5kgs^(-1). The extra power required to move the belt with a velocity of 6ms^(-1) is,
Answer» 30 W 180 W 150 W 1.2 W Answer :B

Discussion

28.	In the arrangement shwon, initially both springs are in their natural length l_(0). The left spring has force constant k_(0)=2N//m and the force constant of the right spring varies as k=k_(0)x, wherex is its compression. The mass of the block is 10/3 kg. At time t=0, the block is given a right ward velocity v_(0)=2 m/s. Both the springs are massless. The distance covered (approximately) by the block before it comes to instantaneous rest for the first time is
Answer» 3.5 m 2.5 m 4.0 m 1.75 m Answer :D

Discussion

29.	Let .I. be the M.I. of uniform square plate about an axis AB that passes through its centre and is parallel to two of its sides. CD is a line in the plane of the plate that passes through the centre of the plate and makes an angle theta with AB. The M.I. of the plate about the axis CD is equal to
Answer» I `I SIN^(2)THETA` `I COS^(2)theta` `I cos^(2)((theta)/(2))` ANSWER :A

Discussion

30.	In the arrangement shwon, initially both springs are in their natural length l_(0). The left spring has force constnat k_(0)=2N//m and the force constant of the right spring varies as k=k_(0)x, wherex is its compression. The mass of the block is 10/3 kg. At time t=0, the block is given a right ward velocity v_(0)=2 m/s. Both the springs are massless. When the blcok comes to instantaneous rest th energy stored in the left spring is
Answer» 3J 12.25 J 6.25 J 16 J Answer :A

Discussion

31.	A body of mass 5kg is under the action of 50N on the horizontal surface. If coefficient of friction in between the surface is one, the distance it travels in 3 s is
Answer» 2M 1.5 m 0.9 m 6m Answer :C

Discussion

32.	While taking a turn, is it possible for a cyclist to lean at an angle of 45^(@) with the vertical?
Answer» Solution :We know that when a cyclist TAKES a turn along a circular path of radius r with velocity v , he leans at an angle of `theta` with the vertical. In this case, `tan theta = (v^(2))/(rg)""`…(1) Again, normal force on the cycle = mg, where m is the mass of the cycle along with the cyclist. So, if the coefficient of friction is `mu`, then limitingfrictional force = `mu` mg. this limiting FRICTIONAL force provides the necessary centripetal force. Hence, ` (mv^(2))/(r) = mu mg " " or, " " mu = (v^(2))/(rg)""`...(2) From the equations (1) and (2) we get, tan`theta = mu`. it is given that`theta = 45^(@) `, so , `mu = tan 45^(@) = ` 1. But the coefficient of friction between the WHEEL and the road can never be 1, actually it is less than 1. Hence, the cycle will skid when the cyclist leans at an angle of `45^(@)` with the vertical.

Discussion

33.	A force of 2hat(i) + 3hat(j) + 2hat(k) N acts a body for 4 s and produces a displacement of 3hat(i) + 4hat(j) + 5hat(k) m calculate the power ?
Answer» 5 W 6 W 7 W 9W Answer :C

Discussion

34.	A tuning fork A produces 4 beats/sec with another tuning fork B of frequency 320 Hz . On filing the fork A , 4 beats/sec are again heard. The frequency of fork A , after filing is
Answer» 324 Hz 320 Hz 316 Hz 314 Hz Answer :A

Discussion

35.	A body is allowed to slide from the top along a smooth inclined plane of length 5m at an angle of inclination 30^(@). If g=10 ms^(-2), time taken by the body to reach the bottom of the plane is
Answer» `(SQRT(3))/(2)s` 1.414 s `(1)/(sqrt(2))s` 2s Answer :B

Discussion

36.	A solid sphere of radius 10 cm is subjected to a pressure of 5 xx 10^(8) Nm ^(-2),then determine the change in its volume. Bulk modulus of material of sphere is 3.14 xx 10 ^(11) Nm ^(-=2).
Answer» <P> Solution :`B = (P)/( Delta V //V) ` ( Neglecting negative sign) `therefore Delta V = (PV)/(B)` `= (5 xx 10 ^(8) xx (4)/(3) pi r ^(3))/( 3.14 xx 10 ^(11))` `= ( 5 xx 10 ^(8) xx 4 xx 3.14 xx (0.1) ^(3))/( 3.14 xx 10 ^(11) xx 3)` `= 0.00666 xx 10 ^(-3)` `~~ 6.7 xx 10 ^(-6) m ^(3)`

Discussion

37.	A boy is sitting on a horizontal platform in the shape of a disc at a distance of 5m from its centre. The boy begins to slip when the speed of wheel exceeds 10 rpm. The coefficient of friction between the boy and platform is: (g = 10 ms^(-2))
Answer» `pi^2//6` `pi^2//18` `pi//6` `pi//2` ANSWER :B

Discussion

38.	A body is moving along a circle of radius 'r' under the influence of centripetal force F. Its total energy is
Answer» RF -rF `(rF)/(2)` `(-rF)/(2)` ANSWER :D

Discussion

39.	If magnitude of the resultant of two vectors equal of magnitude, is equal to the magnitude of either of the vectors, what is the angle between them ?
Answer» SOLUTION :`R = 2P cos""(theta)/(2)`

Discussion

40.	Two blocks of masses m_(1) and m_(2), connected by a weightless spring of stiffness k rest on a smooth horizontal plane as shown in Fig. Block 2 is shifted a small distance x to the left and then released. Find the velocity of centre of mass of the system after block 1 breaks off the wall.
Answer» Solution :If `m_(2)` is shifted by a distance x and released, the mass `m_(1)` will break off from the WALL when the spring restores its natural length and `m_(2)` will start going towards right. At the TIME of breaking `m_(1), m_(2)` will be going towards right with a velocity `v`, which is given as `1/2kx^(2)=1/2m_(2)v^(2)impliesv=(sqrt(k/m_(2)))x` and the velocity of the centre of mass at this instant is `v_(CM)=(m_(1)xx0+m_(2)xxv)/(m_(1)+m_(2))=((sqrt(m_(2)k)x))/(m_(1)+m_(2))`

Discussion

41.	The flow rate of water from a tap of diameter 1.25 cm is 0.48L/min. The coefficient of viscosity of water is 10^(-3) Pa s. (b) After sometime the flow rate is increased to 3L/min. Characterise the flow for both the flow rates.
Answer» Solution :Let the speed of the flow be v and the diameter of the tap be `d=1.25cm`. The VOLUME of the water flowing out PER second is `Q=vxxpid^(2)//4""v=4Q//d^(2)pi` We then estimate the Reynolds number to be `R_(e)=4rhoQ//pideta` `=4XX10^(3)kgm^(-3)xxQ//(3.14xx1.25xx10^(-2)mxx10^(-3)Pas)` `=1.019xx10^(8)m^(-3)sQ` Since initially (a) `Q=0.48L//min=8cm^(3)//s` `=8xx10^(-6)m^(3)s^(-1)`, we obtain, `R_(e)=815` Since this is below 1000, the flow is steady. After some time (b) when `Q=3L//min=50cm^(3)//s` `=5XX10^(-5)m^(3)s^(-1)`, we obtain, `R_(e)=5095`. The flow will be turbulent.

Discussion

42.	When the heavy weight suspended and removed from the metal wire, it cannot get original length. Why?
Answer» Solution :When METAL WIRE is subjected to a deforming force and removed it in elastic limit, the wire REGAINS its original dimension but wire LOSES the elastic properties beyond the elastic limit if more DEFORMATION occur from it.

Discussion

43.	The magnitude of the reusltant of two vectors vecPand vecQ is R. It is given by
Answer» <P>`R=sqrt(P^(2)+Q^(2)+2PQsintheta` `R=sqrt(P^(2)+Q^(2)+2PQcostheta` `R=sqrt(P^(2)+Q^(2)+PQsintheta` `R=sqrt(P^(2)+Q^(2)+PQcostheta` ANSWER :B

Discussion

44.	If the resultant of two equal forces is sqrt(3) times a single . force, find the angle between the forces .
Answer» SOLUTION :Two two forces areequal (i.e.,) P = Q Here R `= sqrt(3P)` `R = sqrt(P^(2) +Q^(2) + 2P Q cos THETA)` Substituting the values `sqrt(3P) = sqrt(P^(2) + P^(2) + 2P^(2) cos theta)` Squaring both sides `3P^(2) + P^(2) + P^(2) + 2P^(2) cos theta` `3P^(2) = P^(2) (1 + 1+ 2COS theta)` `= 2P^(2) + 2P^(2) cos theta` `:. P^(2) = 2P^(2) cos theta` `2 cos theta = 1` `cos theta = (1)/(2) (or) theta = 60^(@)` .

Discussion

45.	Aman can swim with a speed of 4.0 km/h in still water . How long does he take to cross a river 1.0 km wide if the river flows steadily at 3.0 km/h and he makes hisstrokes normal to the river current ? Howfar down the river does he go whenhe reaches the other bank ?
Answer» ANSWER :15 MIN , 750 m

Discussion

46.	Mention the importanc of writing the physical quantities as vectors.
Answer» SOLUTION :REFER to ART. 2 (C ) . 2.

Discussion

47.	Two identical particles each of mass 0.5 kg are interconnected by a light spring of stiffness 100 N//m, time period of small oscillation is
Answer» `(PI)/(5sqrt(2))` s `(pi)/(10sqrt(2))` s `(pi)/(5)s` `(pi)/(10)s` ANSWER :D

Discussion

48.	A steel wire of diammeter 2 mm is pulled to increase its length by 1% what is the restoring force developed in it if young's modulus for steel 2 *10^12 dynes/ cm ^2 .
Answer» SOLUTION :6.28*10^3N

Discussion

49.	The M.I. ofa body is 1.2" kg m"^(2) . Initially the body is rest. In order to produce a rotational kinetic energy of 1500 J an angular acceleration of 25" rad s"^(-2) must be applied about the axis for a duration of
Answer» 3s 4s 8s 10s Answer :A

Discussion

50.	Two particles are thrown a from the same poin in the same verticle plane, as shown in figure simultaneously so as to reach the same maximum height. Then indicale the correct statements :
Answer» Time of flight forB is less than that of A Projection speed of B is greater than that of A Horizontal component of VELOCITY for B is greater than that of A The VERTICAL component of VELOCITIES of both A and B are always equal throughout the DURATION for which both the particles in air. Answer :B::C::D

Discussion

Explore topic-wise InterviewSolutions in Current Affairs.

When the gas from a cooking gas cylinder is used or when a gas stove is lighted what happens to the pressure of the gas in the cylinder?

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A block of mass 10 kg is moving in x-direction with a constant speed of 10 m s^(-1). It is subjected to a retarding force F=-0.1.x J m^(-1) during its travel from x = 20 m to x = 30 m. Its final kinetic energy will be

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A body is projected up along an inclined plane from the bottom with speed V_(1). If it reaches the bottom of the plane with a velocity V_(1) find (v _(1)//v_(2)) if theta is the angle of inclination with the horizontal and mube the co-efficient of friction.

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How is the gravitational force between two point masses affected when they are dipped in water keeping the separation between them the same?

n mole of an ideal gas undergo an isothernal process at temperature T. Further, P-V graph of the process is as shown in the figure. Tangent at point A, cuts the V-axis at point D. AO is the line joining the point A to the origin O of P-V diagram. Choose from following the correct option(s).

Which one of the following is a null vector?

Express 1 atm pressure into N//m^(2) and bar.

If the change in the value of g at a height h above the surface of the earth is same as at depth 'x' below the surface of the earth, then (h lt lt R)

A uniform spherical shell rolls down a fixed inclined pla ne without sliping. Find the ratio of rotational kinetic energy to translational kinetic energy as is reaches lowest point of the incline.

A train has to negotiate a curve of 40 m radius. What is the super elevation of the outer rail required for a speed of 54 kmh^(-1). The distance between the rails is one metre ?

Average velocity of a particle executing SHM in one complete vibration is

A ball is thrown in vertically upward direction. It returns back to the same position in 2s. Then the maximum height achieved by the ball is ...... (Take g = 9.8 ms^(-2))

Sand is fallingon a conveyor belt at the rate of 5kgs^(-1). The extra power required to move the belt with a velocity of 6ms^(-1) is,

Let .I. be the M.I. of uniform square plate about an axis AB that passes through its centre and is parallel to two of its sides. CD is a line in the plane of the plate that passes through the centre of the plate and makes an angle theta with AB. The M.I. of the plate about the axis CD is equal to

A body of mass 5kg is under the action of 50N on the horizontal surface. If coefficient of friction in between the surface is one, the distance it travels in 3 s is

While taking a turn, is it possible for a cyclist to lean at an angle of 45^(@) with the vertical?

A force of 2hat(i) + 3hat(j) + 2hat(k) N acts a body for 4 s and produces a displacement of 3hat(i) + 4hat(j) + 5hat(k) m calculate the power ?

A tuning fork A produces 4 beats/sec with another tuning fork B of frequency 320 Hz . On filing the fork A , 4 beats/sec are again heard. The frequency of fork A , after filing is

A body is allowed to slide from the top along a smooth inclined plane of length 5m at an angle of inclination 30^(@). If g=10 ms^(-2), time taken by the body to reach the bottom of the plane is

A solid sphere of radius 10 cm is subjected to a pressure of 5 xx 10^(8) Nm ^(-2),then determine the change in its volume. Bulk modulus of material of sphere is 3.14 xx 10 ^(11) Nm ^(-=2).

A boy is sitting on a horizontal platform in the shape of a disc at a distance of 5m from its centre. The boy begins to slip when the speed of wheel exceeds 10 rpm. The coefficient of friction between the boy and platform is: (g = 10 ms^(-2))

A body is moving along a circle of radius 'r' under the influence of centripetal force F. Its total energy is

If magnitude of the resultant of two vectors equal of magnitude, is equal to the magnitude of either of the vectors, what is the angle between them ?

Two blocks of masses m_(1) and m_(2), connected by a weightless spring of stiffness k rest on a smooth horizontal plane as shown in Fig. Block 2 is shifted a small distance x to the left and then released. Find the velocity of centre of mass of the system after block 1 breaks off the wall.

The flow rate of water from a tap of diameter 1.25 cm is 0.48L/min. The coefficient of viscosity of water is 10^(-3) Pa s. (b) After sometime the flow rate is increased to 3L/min. Characterise the flow for both the flow rates.

When the heavy weight suspended and removed from the metal wire, it cannot get original length. Why?

The magnitude of the reusltant of two vectors vecPand vecQ is R. It is given by

If the resultant of two equal forces is sqrt(3) times a single . force, find the angle between the forces .

Aman can swim with a speed of 4.0 km/h in still water . How long does he take to cross a river 1.0 km wide if the river flows steadily at 3.0 km/h and he makes hisstrokes normal to the river current ? Howfar down the river does he go whenhe reaches the other bank ?

Mention the importanc of writing the physical quantities as vectors.

Two identical particles each of mass 0.5 kg are interconnected by a light spring of stiffness 100 N//m, time period of small oscillation is

A steel wire of diammeter 2 mm is pulled to increase its length by 1% what is the restoring force developed in it if young's modulus for steel 2 *10^12 dynes/ cm ^2 .

The M.I. ofa body is 1.2" kg m"^(2) . Initially the body is rest. In order to produce a rotational kinetic energy of 1500 J an angular acceleration of 25" rad s"^(-2) must be applied about the axis for a duration of

Two particles are thrown a from the same poin in the same verticle plane, as shown in figure simultaneously so as to reach the same maximum height. Then indicale the correct statements :