50278 + Interview Questions in Physics Page 190 InterviewSolution

9451.	Three slabs of same dimension having dielectric constants K1,K2 and K3 completely fill the space between the plates of a parallel plate capacitor as shown in figure. If C is the initial capacitance of the capacitor, the new capacitance after the introduction of slabs will be:
Answer» Three slabs of same dimension having dielectric constants $K_{1}, K_{2}$ and $K_{3}$ completely fill the space between the plates of a parallel plate capacitor as shown in figure. If $C$ is the initial capacitance of the capacitor, the new capacitance after the introduction of slabs will be:

Discussion

9452.	In the given circuit, if current through inductor L is given as i=i0(1−e−Rt2), then R in ohms is (Write upto two digits after the decimal point.)
Answer» In the given circuit, if current through inductor L is given as $i = i_{0} (1 - e^{\frac{- R t}{2}})$ , then R in ohms is (Write upto two digits after the decimal point.)

Discussion

9453.	a body of mass m is alliwed to fall with help of string with downward acceleration g /6 to dis†an ce x.workdone by string =
Answer» a body of mass m is alliwed to fall with help of string with downward acceleration g /6 to dis†an ce x.workdone by string =

Discussion

9454.	how to find size of image when magnification is not given
Answer» how to find size of image when magnification is not given

Discussion

9455.	Explain clearly, with examples, the distinction between : (a) magnitude of displacement (sometimes called distance) over an interval of time, and the total length of path covered by a particle over the same interval; (b) magnitude of average velocity over an interval of time, and the average speed over the same interval. [Average speed of a particle over an interval of time is defined as the total path length divided by the time interval]. Show in both (a) and (b) that the second quantity is either greater than or equal to the first. When is the equality sign true ? [For simplicity, consider one-dimensional motion only].
Answer» Explain clearly, with examples, the distinction between : (a) magnitude of displacement (sometimes called distance) over an interval of time, and the total length of path covered by a particle over the same interval; (b) magnitude of average velocity over an interval of time, and the average speed over the same interval. [Average speed of a particle over an interval of time is defined as the total path length divided by the time interval]. Show in both (a) and (b) that the second quantity is either greater than or equal to the first. When is the equality sign true ? [For simplicity, consider one-dimensional motion only].

Discussion

9456.	If amplitude of waves at distance r from a point source is A, the amplitude at a distance 2r will be [MP PMT 1985]
Answer» If amplitude of waves at distance r from a point source is A, the amplitude at a distance 2r will be [MP PMT 1985]

9456.

If amplitude of waves at distance r from a point source is A, the amplitude at a distance 2r will be [MP PMT 1985]

Answer»

If amplitude of waves at distance r from a point source is A, the amplitude at a distance 2r will be

[MP PMT 1985]

Discussion

9457.	A block is projected with speed 20 m/s on a roughhorizontal surface. The coefficient of friction (u)between the surfaces varies with time (t) as shownin figure. The speed of body at the end of 4 secondwill be (g = 10 m/s)0(1) 2 m/s(3) 7.2 m/s(2) 5 m/s(4) 9.5 m/s
Answer» A block is projected with speed 20 m/s on a roughhorizontal surface. The coefficient of friction (u)between the surfaces varies with time (t) as shownin figure. The speed of body at the end of 4 secondwill be (g = 10 m/s)0(1) 2 m/s(3) 7.2 m/s(2) 5 m/s(4) 9.5 m/s

Discussion

9458.	A particle of mass 200 MeV/c2 collides with a hydrogen atom at rest. Soon after the collision the particle comes to rest and the atom recoils and goes to its first excited state. The initial kinetic energy of the particle (in eV) is N4. The value of N is:
Answer» A particle of mass $200 {MeV/c}^{2}$ collides with a hydrogen atom at rest. Soon after the collision the particle comes to rest and the atom recoils and goes to its first excited state. The initial kinetic energy of the particle (in $eV$ ) is $\frac{N}{4}$ . The value of $N$ is:

Discussion

9459.	In derivation of connected motion why we are not considering vectors sign?
Answer» In derivation of connected motion why we are not considering vectors sign?

Discussion

9460.	47 A particle of mass M is situated at the centre of a spherical shell of same mass and radius a. The gravitational potential at a point situated at a/2 distance from centre will be
Answer» 47 A particle of mass M is situated at the centre of a spherical shell of same mass and radius a. The gravitational potential at a point situated at a/2 distance from centre will be

Discussion

9461.	A block of mass 2 kg is pushed against a rough vertical wall with a force of 40N, the coefficient of static friction is 0.5. Another horizontal force of 15N is applied on the block in a direction parallel to the wall. Will the block move? If yes then why and in what direction? If it doesn't move find the frictional force by the wall on the block.
Answer» A block of mass 2 kg is pushed against a rough vertical wall with a force of 40N, the coefficient of static friction is 0.5. Another horizontal force of 15N is applied on the block in a direction parallel to the wall. Will the block move? If yes then why and in what direction? If it doesn't move find the frictional force by the wall on the block.

Discussion

9462.	What is the formula of capacitance?
Answer» What is the formula of capacitance?

Discussion

9463.	A PARTICLE EXECUTES WITH TIME PERIOD 12 S .FIND THE TIME TAKEN BY THE PARTICLE TO GO DIRECTLY FROM ITS MEAN POSITION TO HALF ITS AMPLITUDE?
Answer» A PARTICLE EXECUTES WITH TIME PERIOD 12 S .FIND THE TIME TAKEN BY THE PARTICLE TO GO DIRECTLY FROM ITS MEAN POSITION TO HALF ITS AMPLITUDE?

Discussion

9464.	Light of wavelength 2×10^{-3}m falls on a slit of width 4×10^{-3}m .Find angular dispersion of cental maximum
Answer» Light of wavelength 2×10^{-3}m falls on a slit of width 4×10^{-3}m .Find angular dispersion of cental maximum

Discussion

9465.	A straight wire of resis†an ce r per unit lenght is bent to form an angle 2α . a rod of the same wire perpendicular to angle bisector form a closed triangular loop.The loop is placed in uniform magnetic field of induction B .Calculate the current in the loop when rod moves with cons†an t velocity
Answer» A straight wire of resis†an ce r per unit lenght is bent to form an angle 2α . a rod of the same wire perpendicular to angle bisector form a closed triangular loop.The loop is placed in uniform magnetic field of induction B .Calculate the current in the loop when rod moves with cons†an t velocity

Discussion

9466.	A 1kg block situated on a rough incline plane is connected to a spring of negligible mass having spring constant 100Nm−1 as shown in the figure. The block is released from rest with the spring in the unstretched position. The block moves 10cm down the incline before coming to rest. The coefficient of friction between the block and the incline is (take g = 10ms−2 and assume that the pulley is frictionless)
Answer» A 1kg block situated on a rough incline plane is connected to a spring of negligible mass having spring constant $100 N m^{- 1}$ as shown in the figure. The block is released from rest with the spring in the unstretched position. The block moves 10cm down the incline before coming to rest. The coefficient of friction between the block and the incline is (take g = $10 m s^{- 2}$ and assume that the pulley is frictionless)

9466.

A 1kg block situated on a rough incline plane is connected to a spring of negligible mass having spring constant 100Nm−1 as shown in the figure. The block is released from rest with the spring in the unstretched position. The block moves 10cm down the incline before coming to rest. The coefficient of friction between the block and the incline is (take g = 10ms−2 and assume that the pulley is frictionless)

Answer»

A 1kg block situated on a rough incline plane is connected to a spring of negligible mass having spring constant $100 N m^{- 1}$ as shown in the figure. The block is released from rest with the spring in the unstretched position. The block moves 10cm down the incline before coming to rest. The coefficient of friction between the block and the incline is (take g = $10 m s^{- 2}$ and assume that the pulley is frictionless)

Discussion

9467.	A body has charge (q) on it. Which of following is not the possible value of charge (q) on the body ?
Answer» A body has charge (q) on it. Which of following is not the possible value of charge (q) on the body ?

Discussion

9468.	In a photoelectric experiment, kinetic energy of photoelectron is 18.210 power -19 J. The wavelength of incident light (approx) , if work function of metal is 1 eV, is (planck's constant = 6.610 power -34 J s and 1 eV = 1.610 power -19 J
Answer» In a photoelectric experiment, kinetic energy of photoelectron is 18.210 power -19 J. The wavelength of incident light (approx) , if work function of metal is 1 eV, is (planck's constant = 6.610 power -34 J s and 1 eV = 1.610 power -19 J

Discussion

9469.	Two trees are at distance of 3.14 m from each other. What should be the maximum distance of an observer from tree to see them separately.1. 21.6 km 2. 10.8 km3. 15 km4. 25.2 km
Answer» Two trees are at distance of 3.14 m from each other. What should be the maximum distance of an observer from tree to see them separately. 1. 21.6 km 2. 10.8 km 3. 15 km 4. 25.2 km

Discussion

9470.	50.A projectile is fired with a speed u at an angle theta above a horizontal feild. The coefficient of restitution of collision between the projectile and the field is e. How far from the starting point, does the projectileakes its second collision with the field?
Answer» 50.A projectile is fired with a speed u at an angle theta above a horizontal feild. The coefficient of restitution of collision between the projectile and the field is e. How far from the starting point, does the projectileakes its second collision with the field?

Discussion

9471.	Two carts of masses 200 kg and 300 kg on horizontal rails are pushed apart. Suppose the coefficient of friction between the carts and the rails are same. If the 200 kg cart travels a distance of 36 m and stops, then the distance travelled by the cart weighing 300 kg is
Answer» Two carts of masses 200 kg and 300 kg on horizontal rails are pushed apart. Suppose the coefficient of friction between the carts and the rails are same. If the 200 kg cart travels a distance of 36 m and stops, then the distance travelled by the cart weighing 300 kg is

9471.

Two carts of masses 200 kg and 300 kg on horizontal rails are pushed apart. Suppose the coefficient of friction between the carts and the rails are same. If the 200 kg cart travels a distance of 36 m and stops, then the distance travelled by the cart weighing 300 kg is

Answer»

Two carts of masses 200 kg and 300 kg on horizontal rails are pushed apart. Suppose the coefficient of friction between the carts and the rails are same. If the 200 kg cart travels a distance of 36 m and stops, then the distance travelled by the cart weighing 300 kg is

Discussion

9472.	The area (in sq.units) bounded between curves y2−4y−4x+12=0 and x2−4x−3y+10=0, is
Answer» The area (in $sq.units$ ) bounded between curves $y^{2} - 4 y - 4 x + 12 = 0$ and $x^{2} - 4 x - 3 y + 10 = 0,$ is

Discussion

9473.	Theterminology of different parts of the electromagnetic spectrum isgiven in the text. Use the formula E= hν(for energy of a quantum of radiation: photon) and obtain the photonenergy in units of eV for different parts of the electromagneticspectrum. In what way are the different scales of photon energiesthat you obtain related to the sources of electromagnetic radiation?
Answer» The terminology of different parts of the electromagnetic spectrum is given in the text. Use the formula E = hν (for energy of a quantum of radiation: photon) and obtain the photon energy in units of eV for different parts of the electromagnetic spectrum. In what way are the different scales of photon energies that you obtain related to the sources of electromagnetic radiation?

Discussion

9474.	The power of a thin convex lens (aμg=1.5) is +5.0 D. When it is placed in a liquid of refractive index aμl,then it behaves as a concave lens of local length 100 cm. The refractive index of the liquid aμl will be
Answer» The power of a thin convex lens $(_{a} μ_{g} = 1.5)$ is +5.0 D. When it is placed in a liquid of refractive index $_{a} μ_{l}$ ,then it behaves as a concave lens of local length 100 cm. The refractive index of the liquid $_{a} μ_{l}$ will be

Discussion

9475.

A conducting shell of inner radius R1 and outer radius R2 is given a charge +Q. A point charge q1 is placed inside the shell and q2 is placed outside the shell.Then for various locations of q1 and q2, match the following entries of column−I with the entries of column−II. Column-IColumn-II(i). If q1 is at center and q2=0 , then →E at center of shell due to charge on outer surface of shell is(a). q14πε0r2(ii). If q1 is at center and q2 is at distance r from the center, then →E at a point distant r2 (>r) from the center of the shell due to outer surface charge is(b). Zero(iii). If q1 is not at center and q2=0 , then →E at point P (P is at distance r from q1 due to charge of the inner surface of shell) is(c). Cant be determined

Answer»

A conducting shell of inner radius $R_{1}$ and outer radius $R_{2}$ is given a charge $+ Q$ . A point charge $q_{1}$ is placed inside the shell and $q_{2}$ is placed outside the shell.

Then for various locations of $q_{1}$ and $q_{2}$ , match the following entries of column $- I$ with the entries of column $- II$ .

Column- $I$	Column- $II$
$(i) .$ If $q_{1}$ is at center and $q_{2} = 0$ , then $\to E$ at center of shell due to charge on outer surface of shell is	$(a) . \frac{q_{1}}{4 π ε_{0} r^{2}}$
$(ii) .$ If $q_{1}$ is at center and $q_{2}$ is at distance $r$ from the center, then $\to E$ at a point distant $r_{2}$ ( $> r$ ) from the center of the shell due to outer surface charge is	$(b) .$ Zero
$(iii) .$ If $q_{1}$ is not at center and $q_{2} = 0$ , then $\to E$ at point $P$ ( $P$ is at distance $r$ from $q_{1}$ due to charge of the inner surface of shell) is	$(c) .$ Cant be determined

Discussion

9476.	Two coherent narrow slits emitting light of wavelength λ in the same phase are placed parallel to each other at a small separation of 2λ. The light is collected on a screen S which is placed at a distance D(>>λ) from the slit S1 as shown in figure. Find the finite distance x such that the intensity at P is equal to the intensity at O.
Answer» Two coherent narrow slits emitting light of wavelength $λ$ in the same phase are placed parallel to each other at a small separation of $2 λ$ . The light is collected on a screen $S$ which is placed at a distance $D (>> λ)$ from the slit $S_{1}$ as shown in figure. Find the finite distance $x$ such that the intensity at $P$ is equal to the intensity at $O$ .

Discussion

9477.	A closed solid conductor of irregular shape is given some charge. Which of the following statement is correct?Options:Potential of conductor will change if its shape is changedElectric field inside it is non-zeroAll points on its surface will have same-charge densityAll of these
Answer» A closed solid conductor of irregular shape is given some charge. Which of the following statement is correct? Options: Potential of conductor will change if its shape is changed Electric field inside it is non-zero All points on its surface will have same-charge density All of these

Discussion

9478.	A ball of mass 'm' moving horizontally at a speed 'v' collides with the bob of a simple pendulum at rest. The mass of the bob is also 'm'. If the collision is perfectly inelastic, the height to which the two balls rise after the collision will be given by
Answer» A ball of mass 'm' moving horizontally at a speed 'v' collides with the bob of a simple pendulum at rest. The mass of the bob is also 'm'. If the collision is perfectly inelastic, the height to which the two balls rise after the collision will be given by

Discussion

9479.	5. THE VALUE OF(1/27)raise to the power-2/3 is?
Answer» 5. THE VALUE OF(1/27)raise to the power-2/3 is?

Discussion

9480.	There is a horizontal curve of radius 360m and length 180m. Calculate the clearance required from the central line on the inner side of the curve, so as to provide an overtaking sight distance of 250m.19.85
Answer» There is a horizontal curve of radius $360 m$ and length $180 m$ . Calculate the clearance required from the central line on the inner side of the curve, so as to provide an overtaking sight distance of $250 m$ . 19.85

9480.

There is a horizontal curve of radius 360m and length 180m. Calculate the clearance required from the central line on the inner side of the curve, so as to provide an overtaking sight distance of 250m.19.85

Answer»

There is a horizontal curve of radius $360 m$ and length $180 m$ . Calculate the clearance required from the central line on the inner side of the curve, so as to provide an overtaking sight distance of $250 m$ .

19.85

Discussion

9481.	Explain the Primary and Secondary Rainbows ?
Answer» Explain the Primary and Secondary Rainbows ?

Discussion

9482.	Two trains A and B, 100 m and 60 m long respectively, are moving in opposite directions on parallel tracks. The velocity of the shorter train is 5 times that of the longer one. If the trains take 2 s to cross each other, the velocity of the shorter train is
Answer» Two trains A and B, $100 m$ and $60 m$ long respectively, are moving in opposite directions on parallel tracks. The velocity of the shorter train is $5$ times that of the longer one. If the trains take $2 s$ to cross each other, the velocity of the shorter train is

Discussion

9483.	The extension in a string, obeying Hook's law, is x. The speed of sound in the stretched string is v. If the extension in the string is increased to 1.5 x, the speed of sound will be :
Answer» The extension in a string, obeying Hook's law, is $x$ . The speed of sound in the stretched string is $v$ . If the extension in the string is increased to $1.5 x$ , the speed of sound will be :

Discussion

9484.	A small mass m is attached to a massless string whose other end is fixed at P as shown in the figure. The mass is undergoing circular motion in the x-y plane with center at O and constant angular speed ω. If the angular momentum of the system calculated about O and P are denoted by →L0 and →Lr respectively, then
Answer» A small mass m is attached to a massless string whose other end is fixed at P as shown in the figure. The mass is undergoing circular motion in the x-y plane with center at O and constant angular speed $ω$ . If the angular momentum of the system calculated about O and P are denoted by ${\to L}_{0} a n d {\to L}_{r}$ respectively, then

9484.

A small mass m is attached to a massless string whose other end is fixed at P as shown in the figure. The mass is undergoing circular motion in the x-y plane with center at O and constant angular speed ω. If the angular momentum of the system calculated about O and P are denoted by →L0 and →Lr respectively, then

Answer»

A small mass m is attached to a massless string whose other end is fixed at P as shown in the figure. The mass is undergoing circular motion in the x-y plane with center at O and constant angular speed $ω$ . If the angular momentum of the system calculated about O and P are denoted by ${\to L}_{0} a n d {\to L}_{r}$ respectively, then

Discussion

9485.	A light rod carries three equal masses A, B and Cas shown in the figure. What will be the velocity ofB in the vertical position of the rod, if it is releasedfrom horizontal position as shown in the figure?
Answer» A light rod carries three equal masses A, B and Cas shown in the figure. What will be the velocity ofB in the vertical position of the rod, if it is releasedfrom horizontal position as shown in the figure?

Discussion

9486.	Two seconds after projection a projectile is travelling in a direction inclined at 30∘ to the horizontal after one more sec, it is travelling horizontally, the magnitude and direction of its velocity are
Answer» Two seconds after projection a projectile is travelling in a direction inclined at $30^{\circ}$ to the horizontal after one more sec, it is travelling horizontally, the magnitude and direction of its velocity are

Discussion

9487.	The intensity of the sunlight reaching the earth is 1.380Wm−2 Assume this light to be a plane, monochromatic wave. Find the amplitudes of electric and magnetic fields in this wave
Answer» The intensity of the sunlight reaching the earth is $1.380 W m^{- 2}$ Assume this light to be a plane, monochromatic wave. Find the amplitudes of electric and magnetic fields in this wave

Discussion

9488.	A point source of light is moving at a rate of 2 cm-s−1 towards a thin convex lens of focal length 10 cm along its optical axis. When the source is 15 cm away from the lens the image is moving at
Answer» A point source of light is moving at a rate of 2 cm-s $^{- 1}$ towards a thin convex lens of focal length 10 cm along its optical axis. When the source is 15 cm away from the lens the image is moving at

Discussion

9489.	Which of the following is an extensive property A.) molar entropy B.) specific volume C.) Boiling point D.) none of these
Answer» Which of the following is an extensive property A.) molar entropy B.) specific volume C.) Boiling point D.) none of these

9489.

Which of the following is an extensive property A.) molar entropy B.) specific volume C.) Boiling point D.) none of these

Answer»

Which of the following is an extensive property

A.) molar entropy

B.) specific volume

C.) Boiling point

D.) none of these

Discussion

9490.	If electronic charge e, electron mass m, speed of light in vaccum c and Plank's constant h are taken as fundamental quantities, the permeability of vaccum μ0 can be expressed in units of Hint: [h]=[ML2T−1],[μ0]=[MLT−2A−2]
Answer» If electronic charge $e$ , electron mass $m$ , speed of light in vaccum $c$ and Plank's constant $h$ are taken as fundamental quantities, the permeability of vaccum $μ_{0}$ can be expressed in units of Hint: $[h] = [M L^{2} T^{- 1}], [μ_{0}] = [M L T^{- 2} A^{- 2}]$

Discussion

9491.	The resistance per unit length of a wire is 10−6 Ω/m. It is bent in the form of a circle of diameter 2 m. A wire of same material and cross sectional area is connected across its diameter. The total resistance across its diameter AB will be
Answer» The resistance per unit length of a wire is $10^{- 6} Ω / m$ . It is bent in the form of a circle of diameter 2 m. A wire of same material and cross sectional area is connected across its diameter. The total resistance across its diameter $A B$ will be

Discussion

9492.	A rectangular coil is uniformly rotating in a uniform mag feild such that axis of rotation is perpendicular to direction of mag field .when the plane of coil is parallel to mag feild the mag flux and induced emf are a. 0 ,0 b.0, max c.max, 0 d.max,max
Answer» A rectangular coil is uniformly rotating in a uniform mag feild such that axis of rotation is perpendicular to direction of mag field .when the plane of coil is parallel to mag feild the mag flux and induced emf are a. 0 ,0 b.0, max c.max, 0 d.max,max

Discussion

9493.	Calculate the energy in joule corresponding to light of wavelength 45 nm: (Planck's constant h=6.63×10−34Js; speed of light c=3×108 ms−1)
Answer» Calculate the energy in joule corresponding to light of wavelength 45 nm: (Planck's constant $h = 6.63 \times 10^{- 34} J s;$ speed of light $c = 3 \times 10^{8} m s^{- 1}$ )

Discussion

9494.	If I consider thethe Newton's third law of motion, then is it enough for me to train just my legs and make them very strong, stronger than the other Sumo wrestler to defeat him in a fight? I mean being able to push him out of the ring?
Answer» If I consider thethe Newton's third law of motion, then is it enough for me to train just my legs and make them very strong, stronger than the other Sumo wrestler to defeat him in a fight? I mean being able to push him out of the ring?

Discussion

9495.	A body of mass 1 kg travelling due East with 3 m/s turns due North to travel with the same velocity. Find the net force exerted on the body for it to turn if it takes 0.01 sec to turn
Answer» A body of mass 1 $k g$ travelling due East with $3 m / s$ turns due North to travel with the same velocity. Find the net force exerted on the body for it to turn if it takes $0.01$ sec to turn

Discussion

9496.	Two blocks of masses 8kg and 5kg are connected with a rod of mass 3kg . The 8kg mass is pulled with a rod of mass 3kg . The 8kg mass is pulled with force of 180 N . The tension in rod at contact point of 8 kg block is
Answer» Two blocks of masses 8kg and 5kg are connected with a rod of mass 3kg . The 8kg mass is pulled with a rod of mass 3kg . The 8kg mass is pulled with force of 180 N . The tension in rod at contact point of 8 kg block is

Discussion

9497.	two particles of mass 2 kg and 4 kg are projected from the top of a tower simultaneously such that 2 kg is with speed 20 m/s at an angle 30 above horizontal and 4 kg is with 40 m/s horizontally. Acceleration of centre of mass of the system of two particles is
Answer» two particles of mass 2 kg and 4 kg are projected from the top of a tower simultaneously such that 2 kg is with speed 20 m/s at an angle 30 above horizontal and 4 kg is with 40 m/s horizontally. Acceleration of centre of mass of the system of two particles is

Discussion

9498.	If a ball of steel (density ρs=7.8 g/cm3) attains a terminal velocity of 10 cm/s when falling in a tank of water (coefficient of viscosity, ηw=8.5×10−4 Pa-s). Then, its terminal velocity in glycerine (ρg=1.2 g/cm3,ηg=13.2 Pa-s) would be nearly:
Answer» If a ball of steel (density $ρ_{s} = 7.8 {g/cm}^{3}$ ) attains a terminal velocity of $10 cm/s$ when falling in a tank of water (coefficient of viscosity, $η_{w} = 8.5 \times 10^{- 4} Pa-s$ ). Then, its terminal velocity in glycerine ( $ρ_{g} = 1.2 {g/cm}^{3}, η_{g} = 13.2 Pa-s$ ) would be nearly:

Discussion

9499.	34. A cricketer catches a ball of mass 200g in 0.2 s initially moving with speed of 30m/s he experience an average force of the magnitude of
Answer» 34. A cricketer catches a ball of mass 200g in 0.2 s initially moving with speed of 30m/s he experience an average force of the magnitude of

Discussion

9500.	A ball is projected from an inclined plane having inclination θ, normal to the plane with speed u. It strikes the vertical wall horizontally and again it stikes the inclined plane. If all the collisions are elastic, find the time taken by the ball to hit the inclined plane.
Answer» A ball is projected from an inclined plane having inclination $θ$ , normal to the plane with speed $u$ . It strikes the vertical wall horizontally and again it stikes the inclined plane. If all the collisions are elastic, find the time taken by the ball to hit the inclined plane.

Discussion

Explore topic-wise InterviewSolutions in .

Three slabs of same dimension having dielectric constants K1,K2 and K3 completely fill the space between the plates of a parallel plate capacitor as shown in figure. If C is the initial capacitance of the capacitor, the new capacitance after the introduction of slabs will be:

In the given circuit, if current through inductor L is given as i=i0(1−e−Rt2), then R in ohms is (Write upto two digits after the decimal point.)

a body of mass m is alliwed to fall with help of string with downward acceleration g /6 to dis†an ce x.workdone by string =

how to find size of image when magnification is not given

If amplitude of waves at distance r from a point source is A, the amplitude at a distance 2r will be [MP PMT 1985]

A block is projected with speed 20 m/s on a roughhorizontal surface. The coefficient of friction (u)between the surfaces varies with time (t) as shownin figure. The speed of body at the end of 4 secondwill be (g = 10 m/s)0(1) 2 m/s(3) 7.2 m/s(2) 5 m/s(4) 9.5 m/s

A particle of mass 200 MeV/c2 collides with a hydrogen atom at rest. Soon after the collision the particle comes to rest and the atom recoils and goes to its first excited state. The initial kinetic energy of the particle (in eV) is N4. The value of N is:

In derivation of connected motion why we are not considering vectors sign?

47 A particle of mass M is situated at the centre of a spherical shell of same mass and radius a. The gravitational potential at a point situated at a/2 distance from centre will be

What is the formula of capacitance?

A PARTICLE EXECUTES WITH TIME PERIOD 12 S .FIND THE TIME TAKEN BY THE PARTICLE TO GO DIRECTLY FROM ITS MEAN POSITION TO HALF ITS AMPLITUDE?

Light of wavelength 2×10^{-3}m falls on a slit of width 4×10^{-3}m .Find angular dispersion of cental maximum

A body has charge (q) on it. Which of following is not the possible value of charge (q) on the body ?

In a photoelectric experiment, kinetic energy of photoelectron is 18.210 power -19 J. The wavelength of incident light (approx) , if work function of metal is 1 eV, is (planck's constant = 6.610 power -34 J s and 1 eV = 1.610 power -19 J

Two trees are at distance of 3.14 m from each other. What should be the maximum distance of an observer from tree to see them separately.1. 21.6 km 2. 10.8 km3. 15 km4. 25.2 km

50.A projectile is fired with a speed u at an angle theta above a horizontal feild. The coefficient of restitution of collision between the projectile and the field is e. How far from the starting point, does the projectileakes its second collision with the field?

Two carts of masses 200 kg and 300 kg on horizontal rails are pushed apart. Suppose the coefficient of friction between the carts and the rails are same. If the 200 kg cart travels a distance of 36 m and stops, then the distance travelled by the cart weighing 300 kg is

The area (in sq.units) bounded between curves y2−4y−4x+12=0 and x2−4x−3y+10=0, is

The power of a thin convex lens (aμg=1.5) is +5.0 D. When it is placed in a liquid of refractive index aμl,then it behaves as a concave lens of local length 100 cm. The refractive index of the liquid aμl will be

A closed solid conductor of irregular shape is given some charge. Which of the following statement is correct?Options:Potential of conductor will change if its shape is changedElectric field inside it is non-zeroAll points on its surface will have same-charge densityAll of these

A ball of mass 'm' moving horizontally at a speed 'v' collides with the bob of a simple pendulum at rest. The mass of the bob is also 'm'. If the collision is perfectly inelastic, the height to which the two balls rise after the collision will be given by

5. THE VALUE OF(1/27)raise to the power-2/3 is?

There is a horizontal curve of radius 360m and length 180m. Calculate the clearance required from the central line on the inner side of the curve, so as to provide an overtaking sight distance of 250m.19.85

Explain the Primary and Secondary Rainbows ?

Two trains A and B, 100 m and 60 m long respectively, are moving in opposite directions on parallel tracks. The velocity of the shorter train is 5 times that of the longer one. If the trains take 2 s to cross each other, the velocity of the shorter train is

The extension in a string, obeying Hook's law, is x. The speed of sound in the stretched string is v. If the extension in the string is increased to 1.5 x, the speed of sound will be :

A light rod carries three equal masses A, B and Cas shown in the figure. What will be the velocity ofB in the vertical position of the rod, if it is releasedfrom horizontal position as shown in the figure?

Two seconds after projection a projectile is travelling in a direction inclined at 30∘ to the horizontal after one more sec, it is travelling horizontally, the magnitude and direction of its velocity are

The intensity of the sunlight reaching the earth is 1.380Wm−2 Assume this light to be a plane, monochromatic wave. Find the amplitudes of electric and magnetic fields in this wave

A point source of light is moving at a rate of 2 cm-s−1 towards a thin convex lens of focal length 10 cm along its optical axis. When the source is 15 cm away from the lens the image is moving at

Which of the following is an extensive property A.) molar entropy B.) specific volume C.) Boiling point D.) none of these

If electronic charge e, electron mass m, speed of light in vaccum c and Plank's constant h are taken as fundamental quantities, the permeability of vaccum μ0 can be expressed in units of Hint: [h]=[ML2T−1],[μ0]=[MLT−2A−2]

The resistance per unit length of a wire is 10−6 Ω/m. It is bent in the form of a circle of diameter 2 m. A wire of same material and cross sectional area is connected across its diameter. The total resistance across its diameter AB will be

A rectangular coil is uniformly rotating in a uniform mag feild such that axis of rotation is perpendicular to direction of mag field .when the plane of coil is parallel to mag feild the mag flux and induced emf are a. 0 ,0 b.0, max c.max, 0 d.max,max

Calculate the energy in joule corresponding to light of wavelength 45 nm: (Planck's constant h=6.63×10−34Js; speed of light c=3×108 ms−1)

If I consider thethe Newton's third law of motion, then is it enough for me to train just my legs and make them very strong, stronger than the other Sumo wrestler to defeat him in a fight? I mean being able to push him out of the ring?

A body of mass 1 kg travelling due East with 3 m/s turns due North to travel with the same velocity. Find the net force exerted on the body for it to turn if it takes 0.01 sec to turn

Two blocks of masses 8kg and 5kg are connected with a rod of mass 3kg . The 8kg mass is pulled with a rod of mass 3kg . The 8kg mass is pulled with force of 180 N . The tension in rod at contact point of 8 kg block is

two particles of mass 2 kg and 4 kg are projected from the top of a tower simultaneously such that 2 kg is with speed 20 m/s at an angle 30 above horizontal and 4 kg is with 40 m/s horizontally. Acceleration of centre of mass of the system of two particles is

If a ball of steel (density ρs=7.8 g/cm3) attains a terminal velocity of 10 cm/s when falling in a tank of water (coefficient of viscosity, ηw=8.5×10−4 Pa-s). Then, its terminal velocity in glycerine (ρg=1.2 g/cm3,ηg=13.2 Pa-s) would be nearly:

34. A cricketer catches a ball of mass 200g in 0.2 s initially moving with speed of 30m/s he experience an average force of the magnitude of

A ball is projected from an inclined plane having inclination θ, normal to the plane with speed u. It strikes the vertical wall horizontally and again it stikes the inclined plane. If all the collisions are elastic, find the time taken by the ball to hit the inclined plane.