50278 + Interview Questions in Physics Page 110 InterviewSolution

5451.	A particle is acted upon by a force of constant magnitude which is always perpendicular to the instantaneous velocity of the particle. The motion of the particle takes place in a plane. It follows that
Answer» A particle is acted upon by a force of constant magnitude which is always perpendicular to the instantaneous velocity of the particle. The motion of the particle takes place in a plane. It follows that

Discussion

5452.	A ball of mass m slides down a fixed sphere. Find the velocity of the ball when it makes an angle θ with the vertical as shown in the figure, if it is released from rest from the topmost position. The sphere has radius R and ball has radius r. Assume the sphere to be smooth.
Answer» A ball of mass $m$ slides down a fixed sphere. Find the velocity of the ball when it makes an angle $θ$ with the vertical as shown in the figure, if it is released from rest from the topmost position. The sphere has radius $R$ and ball has radius $r$ . Assume the sphere to be smooth.

Discussion

5453.	An electron of energy 150 eV has wavelength of 10^{-10} m. The wavelength of a 0.60 keV electron is (a) 0.50 A^{†extdegree }(b) 0.75 A^{†extdegree }(c) 1.2 A^{†extdegree }(d) 1.5 A^†extdegree.
Answer» An electron of energy 150 eV has wavelength of 10^{-10} m. The wavelength of a 0.60 keV electron is (a) 0.50 A^{†extdegree }(b) 0.75 A^{†extdegree }(c) 1.2 A^{†extdegree }(d) 1.5 A^†extdegree.

Discussion

5454.	A pendulum consists of a bob of mass m=0.1 kg and a massless inextensible string of length L=1.0 m. It is suspended from a fixed point at height H=0.9 m above a frictionless horizontal floor. Initially, the bob of the pendulum is lying on the floor at rest vertically below the point of suspension. A horizontal impulse P=0.2 kg-m/s is imparted to the bob at some instant. After the bob slides for some distance, the string becomes taut, and the bob lifts off the floor. The magnitude of the angular momentum of the pendulum about the point of suspension just before the bob lifts off is J kg-m2/s. The kinetic energy of the pendulum just after the lift-off is K Joules.The value of K up to two decimal places is -
Answer» A pendulum consists of a bob of mass $m = 0.1 kg$ and a massless inextensible string of length $L = 1.0 m$ . It is suspended from a fixed point at height $H = 0.9 m$ above a frictionless horizontal floor. Initially, the bob of the pendulum is lying on the floor at rest vertically below the point of suspension. A horizontal impulse $P = 0.2 kg-m/s$ is imparted to the bob at some instant. After the bob slides for some distance, the string becomes taut, and the bob lifts off the floor. The magnitude of the angular momentum of the pendulum about the point of suspension just before the bob lifts off is $J {kg-m}^{2} /s$ . The kinetic energy of the pendulum just after the lift-off is $K Joules$ . The value of $K$ up to two decimal places is -

Discussion

5455.	What is the minimum thickness of a soap bubble needed for constructive interference of reflected light if the light incident on the film is of wavelength 900 nm and refractive index of the film is 1.5.
Answer» What is the minimum thickness of a soap bubble needed for constructive interference of reflected light if the light incident on the film is of wavelength $900 nm$ and refractive index of the film is $1.5.$

Discussion

5456.	What is wane front ? State its relation with ray of light .
Answer» What is wane front ? State its relation with ray of light .

Discussion

5457.	Area of ring
Answer» Area of ring

Discussion

5458.	A hollow sphere of radius r=20 cm and mass m=1 kg has a charge of Q=1 C distributed uniformly over its surface. If the sphere is rotated about a diameter with an angular speed ω=30 rad/s then its magnetic moment is measured to be 10x Am2. Find x .
Answer» A hollow sphere of radius $r = 20 cm$ and mass $m = 1 kg$ has a charge of $Q = 1 C$ distributed uniformly over its surface. If the sphere is rotated about a diameter with an angular speed $ω = 30 rad/s$ then its magnetic moment is measured to be $10 x {Am}^{2}$ . Find $x$ .

Discussion

5459.	20.IS THERE ANY REASON -THE THRUST FACED DURING UPTHRUST ALWAYS POINT TOWARDS UPWARD DIRECTION AND NOT IN DOWNWARD DIRECTION ?
Answer» 20.IS THERE ANY REASON -THE THRUST FACED DURING UPTHRUST ALWAYS POINT TOWARDS UPWARD DIRECTION AND NOT IN DOWNWARD DIRECTION ?

Discussion

5460.	A particle of mass m having de Broglie wavelength λ collides elastically (e=1) with another particle of mass 2m initialy at rest, de Broglie wavelength of particle of mass `2m` after collision is n4λ, then `n` is [collision is head on ]
Answer» A particle of mass $m$ having de Broglie wavelength $λ$ collides elastically $(e = 1)$ with another particle of mass $2 m$ initialy at rest, de Broglie wavelength of particle of mass `2m` after collision is $\frac{n}{4} λ$ , then `n` is [collision is head on ]

Discussion

5461.	A particle is projected from the ground with an initial speed u at an angle θ with horizontal. The average velocity of the particle between its point of projection and the highest point of its trajectory is
Answer» A particle is projected from the ground with an initial speed $u$ at an angle $θ$ with horizontal. The average velocity of the particle between its point of projection and the highest point of its trajectory is

Discussion

5462.	Find the momentum of a 2.53 g mass moving with speed 16.2m/s upto appropriate significant figures
Answer» Find the momentum of a 2.53 g mass moving with speed 16.2m/s upto appropriate significant figures

Discussion

5463.	7. A man generates a symmetrical pulse in a string by moving his hands up and down .At t=0 the point in his hands moves downward.the pulse travel with 3ms on string abd his hands passes 6 times in each second from mean postion.then the point on string 3m will reach its upper extreme first time at time t
Answer» 7. A man generates a symmetrical pulse in a string by moving his hands up and down .At t=0 the point in his hands moves downward.the pulse travel with 3ms on string abd his hands passes 6 times in each second from mean postion.then the point on string 3m will reach its upper extreme first time at time t

Discussion

5464.	Two positive ions each carrying a charge q are separated by a dis†an ce d if F is the force of repulsion between the ions the number of electrons mi
Answer» Two positive ions each carrying a charge q are separated by a dis†an ce d if F is the force of repulsion between the ions the number of electrons mi

Discussion

5465.	A metal sheet is to be bent at an angle of 57.3o with a bend radius of 120 mm and the bend allowance for stretch factor 0.6 is 12.3 cm. The thickness of metal is ________ cm. (correct upto one decimal place)0.05
Answer» A metal sheet is to be bent at an angle of ${57.3}^{o}$ with a bend radius of 120 mm and the bend allowance for stretch factor 0.6 is 12.3 cm. The thickness of metal is ________ cm. (correct upto one decimal place) 0.05

Discussion

5466.	Consider the YDSE arrangement shown in figure. If d=10λ, then the position of the 8th maxima is
Answer» Consider the YDSE arrangement shown in figure. If $d = 10 λ$ , then the position of the 8th maxima is

Discussion

5467.	Statement1: In absence of air, projectile motion is always a 2D motion. Statement2: In absence of any external force in 3D space, at any time during its flight Projectile's velocity has only two components.
Answer» Statement1: In absence of air, projectile motion is always a 2D motion. Statement2: In absence of any external force in 3D space, at any time during its flight Projectile's velocity has only two components.

Discussion

5468.	A uniform rod mass m is lying at a distance √3 a from the centre of a sphere of mass M just over the sphere ( where a is the radius of the ring as well as that of the sphere ) . Find the magnitude of the gravitational force between them.
Answer» A uniform rod mass m is lying at a distance √3 a from the centre of a sphere of mass M just over the sphere ( where a is the radius of the ring as well as that of the sphere ) . Find the magnitude of the gravitational force between them.

Discussion

5469.	A conductor of 3 m length, is moving with a speed of 102 m/s. It is moving in a direction, perpendicular to its length, as well as to a magnetic field of 10−3 T. The force required to move it with this constant speed is -
Answer» A conductor of $3 m$ length, is moving with a speed of $10^{2} m/s$ . It is moving in a direction, perpendicular to its length, as well as to a magnetic field of $10^{- 3} T$ . The force required to move it with this constant speed is -

Discussion

5470.	A body is moving with uniform acceleration starting from rest.Match column I with Column II.Column-IColumn-IIa. Its velocity at the end of t sec., 2t sec., 3t sec. etc are in the ratio p. 1:2:3b. Distances covered in 1stt sec.,q. 1:1:1 2ndt sec.,3rd t. sec. are in the ratioc. Distances covered in t sec., 2t sec & r. 1:3:5 3t sec. are in the ratiod. Change in velocity at the end of s. 1:4:9 1stt.sec.,2ndt.sec.,3rdt.sec are in the ratio
Answer» A body is moving with uniform acceleration starting from rest. Match column I with Column II. $\begin{matrix} Column-I & Column-II a. Its velocity at the end of t sec., 2t sec., 3t sec. etc are in the ratio & p. 1 : 2 : 3 b. Distances covered in 1^{s t} t sec., & q. 1 : 1 : 1 2^{n d} t sec ., 3^{r d} t. sec. are in the ratio c. Distances covered in t sec., 2t sec & & r. 1 : 3 : 5 3t sec. are in the ratio d. Change in velocity at the end of & s. 1 : 4 : 9 1^{s t} t.sec ., 2^{n d} t.sec ., 3^{r d} t.sec are in the ratio \end{matrix}$

Discussion

5471.	At what depth from the surface of the earth (in terms of the radius of earth) the acceleration due to gravity will be 2g5 (correct answer + 1, wrong answer - 0.25)
Answer» At what depth from the surface of the earth (in terms of the radius of earth) the acceleration due to gravity will be $\frac{2 g}{5}$ (correct answer + 1, wrong answer - 0.25)

Discussion

5472.	Consider the function y=x2−6x+9. the maximum value of y obtained when x varies over the interval 2 to 5 is
Answer» Consider the function $y = x^{2} - 6 x + 9$ . the maximum value of $y$ obtained when $x$ varies over the interval $2$ to $5$ is

Discussion

5473.	An electron of mass me, initially at rest, moves through a certain distance in a uniform electric field in time t1. A proton of mass mp, which is also initially at rest, takes time t2 to move through an equal distance in this uniform electric field. Neglecting the effect of gravity, the ratio t2/t1 is nearly equal to
Answer» An electron of mass $m_{e}$ , initially at rest, moves through a certain distance in a uniform electric field in time $t_{1}$ . A proton of mass $m_{p}$ , which is also initially at rest, takes time $t_{2}$ to move through an equal distance in this uniform electric field. Neglecting the effect of gravity, the ratio $t_{2} / t_{1}$ is nearly equal to

Discussion

5474.	Figures14.29 correspond to two circular motions. The radius of the circle,the period of revolution, the initial position, and the sense ofrevolution (i.e. clockwise or anti-clockwise) are indicated on eachfigure.Obtainthe corresponding simple harmonic motions of the x-projectionof the radius vector of the revolving particle P, in each case.
Answer» Figures 14.29 correspond to two circular motions. The radius of the circle, the period of revolution, the initial position, and the sense of revolution (i.e. clockwise or anti-clockwise) are indicated on each figure. Obtain the corresponding simple harmonic motions of the x-projection of the radius vector of the revolving particle P, in each case.

5474.

Figures14.29 correspond to two circular motions. The radius of the circle,the period of revolution, the initial position, and the sense ofrevolution (i.e. clockwise or anti-clockwise) are indicated on eachfigure.Obtainthe corresponding simple harmonic motions of the x-projectionof the radius vector of the revolving particle P, in each case.

Answer»

Figures
14.29 correspond to two circular motions. The radius of the circle,
the period of revolution, the initial position, and the sense of
revolution (i.e. clockwise or anti-clockwise) are indicated on each
figure.

Obtain
the corresponding simple harmonic motions of the x-projection
of the radius vector of the revolving particle P, in each case.

Discussion

5475.	What is electromagnetic field?
Answer» What is electromagnetic field?

Discussion

5476.	25.A ball of mass m is thrown from the top of the tower with velocity u downwards and at the same instant another ball of mass 4m is thrown upwards velocity u. The time interval between the balls when they hit the ground is 1)u/g 2)2u/g
Answer» 25.A ball of mass m is thrown from the top of the tower with velocity u downwards and at the same instant another ball of mass 4m is thrown upwards velocity u. The time interval between the balls when they hit the ground is 1)u/g 2)2u/g

Discussion

5477.	Define Escape speed.
Answer» Define Escape speed.

Discussion

5478.	35. In the Bohr model of hydrogen atom the electron makes about 0.610 to the power 16 rev/sec around the nucleus.What is the average current at a point on the orbit of electron?(e=1.610to the power -19 C)
Answer» 35. In the Bohr model of hydrogen atom the electron makes about 0.610 to the power 16 rev/sec around the nucleus.What is the average current at a point on the orbit of electron?(e=1.610to the power -19 C)

Discussion

5479.	An Atwood machine is set up like the figure which is given below. If m1=6.0kg and m2=4.5kg. What is the acceleration of the system when the masses are released? (Take the value of g=10ms−2)
Answer» An Atwood machine is set up like the figure which is given below. If $m_{1} = 6.0 k g$ and $m_{2} = 4.5 k g$ . What is the acceleration of the system when the masses are released? (Take the value of $g = 10 m s^{- 2}$ )

Discussion

5480.	Figure shows a cylindrical tube of length 30 cm which is partitioned by a tight-fitting separator. The separator is very weakly conducting and can freely slide along the tube. Ideal gases are filled in the two parts of the vessel. In the beginning, the temperatures in the parts A and B are 400 K and 100 k respectively. The separator slides to a momentary equilibrium position shown in the figure. Find the final equilibrium position of the separator, reached after a long time.
Answer» Figure shows a cylindrical tube of length 30 cm which is partitioned by a tight-fitting separator. The separator is very weakly conducting and can freely slide along the tube. Ideal gases are filled in the two parts of the vessel. In the beginning, the temperatures in the parts A and B are 400 K and 100 k respectively. The separator slides to a momentary equilibrium position shown in the figure. Find the final equilibrium position of the separator, reached after a long time.

5480.

Figure shows a cylindrical tube of length 30 cm which is partitioned by a tight-fitting separator. The separator is very weakly conducting and can freely slide along the tube. Ideal gases are filled in the two parts of the vessel. In the beginning, the temperatures in the parts A and B are 400 K and 100 k respectively. The separator slides to a momentary equilibrium position shown in the figure. Find the final equilibrium position of the separator, reached after a long time.

Answer»

Figure shows a cylindrical tube of length 30 cm which is partitioned by a tight-fitting separator. The separator is very weakly conducting and can freely slide along the tube. Ideal gases are filled in the two parts of the vessel. In the beginning, the temperatures in the parts A and B are 400 K and 100 k respectively. The separator slides to a momentary equilibrium position shown in the figure. Find the final equilibrium position of the separator, reached after a long time.

Discussion

5481.	White light may be considered to be a mixture of wavelengths λ ranging between 3900 ˚A and 7800 ˚A. An oil film of thickness 10000 ˚A is examined normally by reflected light. If μ=1.4 , then the film appears bright for-
Answer» White light may be considered to be a mixture of wavelengths $λ$ ranging between $3900 ˚ A and 7800 ˚ A .$ An oil film of thickness $10000 ˚ A$ is examined normally by reflected light. If $μ = 1.4$ , then the film appears bright for-

Discussion

5482.	Find the work done in bringing three particles each having a mass of 100 gm. From large distance to the vertices of an equilateral triangle of side 20 cm.
Answer» Find the work done in bringing three particles each having a mass of 100 gm. From large distance to the vertices of an equilateral triangle of side 20 cm.

Discussion

5483.	Which of the following do not depend on the frame of reference? 1. Mass 2. Distance between two points 3. Velocity 4. Distance
Answer» Which of the following do not depend on the frame of reference? 1. Mass 2. Distance between two points 3. Velocity 4. Distance

Discussion

5484.	A particle of mass m is being circulated on a vertical circle of radius r. If the speed of particle at the highest point be v, then A : mg=mv2r B : mg>mv2r C : mg≤ mv2r D : mg≥ mv2r
Answer» A particle of mass m is being circulated on a vertical circle of radius r. If the speed of particle at the highest point be v, then A : mg=mv2r B : mg>mv2r C : mg≤ mv2r D : mg≥ mv2r

Discussion

5485.	84. why the work done by gravitational force of sun during motion of a planet from perihelion to aphelion is negative?
Answer» 84. why the work done by gravitational force of sun during motion of a planet from perihelion to aphelion is negative?

Discussion

5486.	If →a=^i+^j−2^k,→b=^i+^k, then the resultant of {{(→a×→b)×→a}×→a}×→b is
Answer» If $\to a =^i +^j - 2^k, \to b =^i +^k,$ then the resultant of ${{(\to a \times \to b) \times \to a} \times \to a} \times \to b$ is

Discussion

5487.	A long rod is distributed with a charge of linear charge density +lamda ; a point charge of mass m & charge -q is moving in a horizontal circle around the rod with a const. speed. if radius circle r, then find the speed.
Answer» A long rod is distributed with a charge of linear charge density +lamda ; a point charge of mass m & charge -q is moving in a horizontal circle around the rod with a const. speed. if radius circle r, then find the speed.

Discussion

5488.	The radii of circular paths of 2 particles of same mass are in ratio 6:8 then what will be velocities ratio if they have a "constant centripetal force"?in the solution of this q why F1 =F2 taken does constant centripetal force mean by this??
Answer» The radii of circular paths of 2 particles of same mass are in ratio 6:8 then what will be velocities ratio if they have a "constant centripetal force"? in the solution of this q why F1 =F2 taken does constant centripetal force mean by this??

Discussion

5489.	A wire is sliding as shown in the figure. The angle between acceleration and velocity of the wire at the instant shown is :
Answer» A wire is sliding as shown in the figure. The angle between acceleration and velocity of the wire at the instant shown is :

Discussion

5490.	a gas filled in a cylinder its temperature is increased by 20% and volume is decreased by 20% if pressure remains cons†an t what percentage of mass of the gas leaks out
Answer» a gas filled in a cylinder its temperature is increased by 20% and volume is decreased by 20% if pressure remains cons†an t what percentage of mass of the gas leaks out

Discussion

5491.	Three uniform spheres of mass M and radius R each are kept in such a way that each touches the other two. The magnitude of the gravitational force on any of the spheres due to the other two is
Answer» Three uniform spheres of mass M and radius R each are kept in such a way that each touches the other two. The magnitude of the gravitational force on any of the spheres due to the other two is

Discussion

5492.	The pressure of the gas, filled in the bulb of a constant volume gas thermometer are 60 cm and 80 cm of mercury column at 0°C and 100°C respectively. If its bulb is immersed in a liquid at 80°C temperature. Then its pressure in mercury column will be:-(1)66 cm(2)70 cm(3)76 cm(4)78 cm
Answer» The pressure of the gas, filled in the bulb of a constant volume gas thermometer are 60 cm and 80 cm of mercury column at 0°C and 100°C respectively. If its bulb is immersed in a liquid at 80°C temperature. Then its pressure in mercury column will be:- (1)66 cm (2)70 cm (3)76 cm (4)78 cm

Discussion

5493.	Why it's not possible to have projectile to be perpendicular to the initial velocity direction if thetha < 45 degree?
Answer» Why it's not possible to have projectile to be perpendicular to the initial velocity direction if thetha < 45 degree?

Discussion

5494.	The charge (in C) flowing through a resistance R varies with time (in s) as Q=2t–8t2. The total heat produced in the resistance is (for 0≤t≤18 s)
Answer» The charge $(in C)$ flowing through a resistance $R$ varies with time $(in s)$ as $Q = 2 t - 8 t^{2}$ . The total heat produced in the resistance is (for $0 \leq t \leq \frac{1}{8} s$ )

Discussion

5495.	If the rate of change in the circumference of a circle is 0.5 cm/sec, then the rate of change in its area, when the circumference is 10π cm, is equal to(in sq.cm/sec)
Answer» If the rate of change in the circumference of a circle is $0.5 cm/sec$ , then the rate of change in its area, when the circumference is $10 π cm,$ is equal to(in $sq.cm/sec$ )

Discussion

5496.	The surface of a metal is illuminated with the light ofWavelength 400 nm. The kinetic energy of theejected photoelectrons was found to be 1.68 eV.Work function of the metal is about(1) 3.09 eV(3) 4.73 ev(2) 1.42 eV(4) 0.68 ev
Answer» The surface of a metal is illuminated with the light ofWavelength 400 nm. The kinetic energy of theejected photoelectrons was found to be 1.68 eV.Work function of the metal is about(1) 3.09 eV(3) 4.73 ev(2) 1.42 eV(4) 0.68 ev

Discussion

5497.	Block of mass 8 kg moving with a velocity of 36 kilometre per hour. If the velocity is reduced to 18 kilometre per hour in 0.5 seconds What is the retarding force on the
Answer» Block of mass 8 kg moving with a velocity of 36 kilometre per hour. If the velocity is reduced to 18 kilometre per hour in 0.5 seconds What is the retarding force on the

Discussion

5498.	How does weight of a spacecraft changes as it travels from the earth to moon
Answer» How does weight of a spacecraft changes as it travels from the earth to moon

Discussion

5499.	A fish in an aquarium approaches the left wall at a rate of 3 ms−1 & observes a fly approaching it at 8 ms−1. If the refractive index of water is 4/3, find the actual velocity of the fly.
Answer» A fish in an aquarium approaches the left wall at a rate of $3 {ms}^{- 1}$ & observes a fly approaching it at $8 {ms}^{- 1}$ . If the refractive index of water is $4 / 3$ , find the actual velocity of the fly.

Discussion

5500.	Mass of a block of metal is 10 kg and its dimensions are length 50 cm, breadth 10 cm, height 20 cm. (See fig.) If the metal block is placed on the following suface on the table, find out on which of the surface ABCD, CDEF and BCFG will the pressure exerted on the table be maximum.
Answer» Mass of a block of metal is 10 kg and its dimensions are length 50 cm, breadth 10 cm, height 20 cm. (See fig.) If the metal block is placed on the following suface on the table, find out on which of the surface ABCD, CDEF and BCFG will the pressure exerted on the table be maximum.

Discussion

Explore topic-wise InterviewSolutions in .

A particle is acted upon by a force of constant magnitude which is always perpendicular to the instantaneous velocity of the particle. The motion of the particle takes place in a plane. It follows that

A ball of mass m slides down a fixed sphere. Find the velocity of the ball when it makes an angle θ with the vertical as shown in the figure, if it is released from rest from the topmost position. The sphere has radius R and ball has radius r. Assume the sphere to be smooth.

An electron of energy 150 eV has wavelength of 10^{-10} m. The wavelength of a 0.60 keV electron is (a) 0.50 A^{†extdegree }(b) 0.75 A^{†extdegree }(c) 1.2 A^{†extdegree }(d) 1.5 A^†extdegree.

What is the minimum thickness of a soap bubble needed for constructive interference of reflected light if the light incident on the film is of wavelength 900 nm and refractive index of the film is 1.5.

What is wane front ? State its relation with ray of light .

Area of ring

A hollow sphere of radius r=20 cm and mass m=1 kg has a charge of Q=1 C distributed uniformly over its surface. If the sphere is rotated about a diameter with an angular speed ω=30 rad/s then its magnetic moment is measured to be 10x Am2. Find x .

20.IS THERE ANY REASON -THE THRUST FACED DURING UPTHRUST ALWAYS POINT TOWARDS UPWARD DIRECTION AND NOT IN DOWNWARD DIRECTION ?

A particle of mass m having de Broglie wavelength λ collides elastically (e=1) with another particle of mass 2m initialy at rest, de Broglie wavelength of particle of mass `2m` after collision is n4λ, then `n` is [collision is head on ]

A particle is projected from the ground with an initial speed u at an angle θ with horizontal. The average velocity of the particle between its point of projection and the highest point of its trajectory is

Find the momentum of a 2.53 g mass moving with speed 16.2m/s upto appropriate significant figures

Two positive ions each carrying a charge q are separated by a dis†an ce d if F is the force of repulsion between the ions the number of electrons mi

A metal sheet is to be bent at an angle of 57.3o with a bend radius of 120 mm and the bend allowance for stretch factor 0.6 is 12.3 cm. The thickness of metal is ________ cm. (correct upto one decimal place)0.05

Consider the YDSE arrangement shown in figure. If d=10λ, then the position of the 8th maxima is

Statement1: In absence of air, projectile motion is always a 2D motion. Statement2: In absence of any external force in 3D space, at any time during its flight Projectile's velocity has only two components.

A uniform rod mass m is lying at a distance √3 a from the centre of a sphere of mass M just over the sphere ( where a is the radius of the ring as well as that of the sphere ) . Find the magnitude of the gravitational force between them.

A conductor of 3 m length, is moving with a speed of 102 m/s. It is moving in a direction, perpendicular to its length, as well as to a magnetic field of 10−3 T. The force required to move it with this constant speed is -

At what depth from the surface of the earth (in terms of the radius of earth) the acceleration due to gravity will be 2g5 (correct answer + 1, wrong answer - 0.25)

Consider the function y=x2−6x+9. the maximum value of y obtained when x varies over the interval 2 to 5 is

What is electromagnetic field?

25.A ball of mass m is thrown from the top of the tower with velocity u downwards and at the same instant another ball of mass 4m is thrown upwards velocity u. The time interval between the balls when they hit the ground is 1)u/g 2)2u/g

Define Escape speed.

35. In the Bohr model of hydrogen atom the electron makes about 0.6*10 to the power 16 rev/sec around the nucleus.What is the average current at a point on the orbit of electron?(e=1.6*10to the power -19 C)

An Atwood machine is set up like the figure which is given below. If m1=6.0kg and m2=4.5kg. What is the acceleration of the system when the masses are released? (Take the value of g=10ms−2)

White light may be considered to be a mixture of wavelengths λ ranging between 3900 ˚A and 7800 ˚A. An oil film of thickness 10000 ˚A is examined normally by reflected light. If μ=1.4 , then the film appears bright for-

Find the work done in bringing three particles each having a mass of 100 gm. From large distance to the vertices of an equilateral triangle of side 20 cm.

Which of the following do not depend on the frame of reference? 1. Mass 2. Distance between two points 3. Velocity 4. Distance

A particle of mass m is being circulated on a vertical circle of radius r. If the speed of particle at the highest point be v, then A : mg=mv2r B : mg>mv2r C : mg≤ mv2r D : mg≥ mv2r

84. why the work done by gravitational force of sun during motion of a planet from perihelion to aphelion is negative?

If →a=^i+^j−2^k,→b=^i+^k, then the resultant of {{(→a×→b)×→a}×→a}×→b is

A long rod is distributed with a charge of linear charge density +lamda ; a point charge of mass m & charge -q is moving in a horizontal circle around the rod with a const. speed. if radius circle r, then find the speed.

The radii of circular paths of 2 particles of same mass are in ratio 6:8 then what will be velocities ratio if they have a "constant centripetal force"?in the solution of this q why F1 =F2 taken does constant centripetal force mean by this??

A wire is sliding as shown in the figure. The angle between acceleration and velocity of the wire at the instant shown is :

a gas filled in a cylinder its temperature is increased by 20% and volume is decreased by 20% if pressure remains cons†an t what percentage of mass of the gas leaks out

Three uniform spheres of mass M and radius R each are kept in such a way that each touches the other two. The magnitude of the gravitational force on any of the spheres due to the other two is

The pressure of the gas, filled in the bulb of a constant volume gas thermometer are 60 cm and 80 cm of mercury column at 0°C and 100°C respectively. If its bulb is immersed in a liquid at 80°C temperature. Then its pressure in mercury column will be:-(1)66 cm(2)70 cm(3)76 cm(4)78 cm

Why it's not possible to have projectile to be perpendicular to the initial velocity direction if thetha < 45 degree?

The charge (in C) flowing through a resistance R varies with time (in s) as Q=2t–8t2. The total heat produced in the resistance is (for 0≤t≤18 s)

If the rate of change in the circumference of a circle is 0.5 cm/sec, then the rate of change in its area, when the circumference is 10π cm, is equal to(in sq.cm/sec)

The surface of a metal is illuminated with the light ofWavelength 400 nm. The kinetic energy of theejected photoelectrons was found to be 1.68 eV.Work function of the metal is about(1) 3.09 eV(3) 4.73 ev(2) 1.42 eV(4) 0.68 ev

Block of mass 8 kg moving with a velocity of 36 kilometre per hour. If the velocity is reduced to 18 kilometre per hour in 0.5 seconds What is the retarding force on the

How does weight of a spacecraft changes as it travels from the earth to moon

A fish in an aquarium approaches the left wall at a rate of 3 ms−1 &amp; observes a fly approaching it at 8 ms−1. If the refractive index of water is 4/3, find the actual velocity of the fly.

Mass of a block of metal is 10 kg and its dimensions are length 50 cm, breadth 10 cm, height 20 cm. (See fig.) If the metal block is placed on the following suface on the table, find out on which of the surface ABCD, CDEF and BCFG will the pressure exerted on the table be maximum.

35. In the Bohr model of hydrogen atom the electron makes about 0.610 to the power 16 rev/sec around the nucleus.What is the average current at a point on the orbit of electron?(e=1.610to the power -19 C)

A fish in an aquarium approaches the left wall at a rate of 3 ms−1 & observes a fly approaching it at 8 ms−1. If the refractive index of water is 4/3, find the actual velocity of the fly.