50278 + Interview Questions in Physics

1.	Explain the difference between resistance and resistivity.
Answer» Explain the difference between resistance and resistivity.

Discussion

2.	Who discovered the cathode rays ?
Answer» Who discovered the cathode rays ?

Discussion

3.	7.Two particles at a distance 5m apart are thrown towards each other on an inclined smooth plane with equal speeds v. Inclined plane is inclined at an angle of 30 degree with the horizontal. It is known that both the particles move along the same straight line. The particles collide at the point from where the lower particle is thrown. If the value of v is found to be 10/n m/sec. Find n
Answer» 7.Two particles at a distance 5m apart are thrown towards each other on an inclined smooth plane with equal speeds v. Inclined plane is inclined at an angle of 30 degree with the horizontal. It is known that both the particles move along the same straight line. The particles collide at the point from where the lower particle is thrown. If the value of v is found to be 10/n m/sec. Find n

Discussion

4.	One half of a semicircular ring of radius R has charge -Q while the other half has +Q. The ring is placed in the XY plane where a uniform electric field exists E=Eo^i . Find the work required to be done by an external agent to rotate the ring about the z-axis by 90 degrees in a clockwise direction.1). 2(QER)π 2). 8(QER)π 3). 4(QER)π 4). Zero
Answer» One half of a semicircular ring of radius R has charge -Q while the other half has +Q. The ring is placed in the XY plane where a uniform electric field exists $E = E_{o}^i$ . Find the work required to be done by an external agent to rotate the ring about the z-axis by 90 degrees in a clockwise direction. 1). $\frac{2 (Q E R)}{π}$ 2). $\frac{8 (Q E R)}{π}$ 3). $\frac{4 (Q E R)}{π}$ 4). Zero

4.

One half of a semicircular ring of radius R has charge -Q while the other half has +Q. The ring is placed in the XY plane where a uniform electric field exists E=Eo^i . Find the work required to be done by an external agent to rotate the ring about the z-axis by 90 degrees in a clockwise direction.1). 2(QER)π 2). 8(QER)π 3). 4(QER)π 4). Zero

Answer»

One half of a semicircular ring of radius R has charge -Q while the other half has +Q. The ring is placed in the XY plane where a uniform electric field exists $E = E_{o}^i$ . Find the work required to be done by an external agent to rotate the ring about the z-axis by 90 degrees in a clockwise direction.

1). $\frac{2 (Q E R)}{π}$

2). $\frac{8 (Q E R)}{π}$

3). $\frac{4 (Q E R)}{π}$

4). Zero

Discussion

5.	Shown in the figure, is a hollow ice-cream cone (it is open at the top). If its mass is M, radius of its top is R and height H then, its moment of inertia about its axis is:
Answer» Shown in the figure, is a hollow ice-cream cone (it is open at the top). If its mass is $M$ , radius of its top is $R$ and height $H$ then, its moment of inertia about its axis is:

Discussion

6.	A particle of mass 3m is projected from the ground at some angle with horizontal. The horizontal range is R. At the highest point of its path it breaks into two pieces m and 2m. The smaller mass comes to rest and larger mass finally falls at a distance x from the point of projection, where x is equal to
Answer» A particle of mass $3 m$ is projected from the ground at some angle with horizontal. The horizontal range is $R$ . At the highest point of its path it breaks into two pieces $m$ and $2 m$ . The smaller mass comes to rest and larger mass finally falls at a distance $x$ from the point of projection, where $x$ is equal to

Discussion

7.	From a uniformly charged disc of radius r r having surface charge density sigma, a disc of radius r/2 is removed such the dis†an ce between the centre of original sphere and the centre of removed sphere is r/2 . What is electric potential at point lying on the end point of diametre of removed sphere along the diametre of original.sphere which is away from the centre of original.sph?
Answer» From a uniformly charged disc of radius r r having surface charge density sigma, a disc of radius r/2 is removed such the dis†an ce between the centre of original sphere and the centre of removed sphere is r/2 . What is electric potential at point lying on the end point of diametre of removed sphere along the diametre of original.sphere which is away from the centre of original.sph?

Discussion

8.	Motional emf in straight conductor
Answer» Motional emf in straight conductor

Discussion

9.	37 A uniform ladder of length 3.25 m and weighing 250 N is placed against a smooth verticalwall with its lower end 1.25 m from the wall. If coefficient of friction between the ladderand the floor is 0.3, then, find the frictional force acting on the ladder at the point of contactbetween ladder and floor
Answer» 37 A uniform ladder of length 3.25 m and weighing 250 N is placed against a smooth verticalwall with its lower end 1.25 m from the wall. If coefficient of friction between the ladderand the floor is 0.3, then, find the frictional force acting on the ladder at the point of contactbetween ladder and floor

Discussion

10.	An observer stands at a distance of 850 m from the cliff and fires a gun. After what time gap will he hear the echo, if sound travels at a speed of 350ms−1 in air?
Answer» An observer stands at a distance of $850 m$ from the cliff and fires a gun. After what time gap will he hear the echo, if sound travels at a speed of $350 m s^{- 1}$ in air?

Discussion

11.	If position x as a function of time t is given as x=t^3+2t^2 then acceleration at t=2 seconds is (x in metres)
Answer» If position x as a function of time t is given as x=t^3+2t^2 then acceleration at t=2 seconds is (x in metres)

Discussion

12.	(a) At what distance should the lens be held from the figure in Exercise 9.29 in order to view the squares distinctly with the maximum possible magnifying power? (b) What is the magnification in this case? (c) Is the magnification equal to the magnifying power in this case? Explain.
Answer» (a) At what distance should the lens be held from the figure in Exercise 9.29 in order to view the squares distinctly with the maximum possible magnifying power? (b) What is the magnification in this case? (c) Is the magnification equal to the magnifying power in this case? Explain.

Discussion

13.	Derives=vt-1\2(at²)
Answer» Derive s=vt-1\2(at²)

Discussion

14.	A parallel beam of light of wavelength 600 nm is incident normally on a slit of width d. If the distance between the slits and the screen is 0.8 m and the distance of 2nd order maximum from the center of the screen is 15 mm, the width of the slit is,
Answer» A parallel beam of light of wavelength $600 nm$ is incident normally on a slit of width $d$ . If the distance between the slits and the screen is $0.8 m$ and the distance of $2^{nd}$ order maximum from the center of the screen is $15 mm$ , the width of the slit is,

Discussion

15.	In a lake 2m deep, a measuring post of height 3m is fixed vertically. For an angle of incidence of 30° of Sun’s radiations, find the length of the shadow of the post at the bottom surface?(μw = 4/3)
Answer» In a lake 2m deep, a measuring post of height 3m is fixed vertically. For an angle of incidence of 30° of Sun’s radiations, find the length of the shadow of the post at the bottom surface?(μw = 4/3)

Discussion

16.	Through the oil drop experiment, how did Millikan calculate the charge of an electron?
Answer» Through the oil drop experiment, how did Millikan calculate the charge of an electron?

Discussion

17.	A person needs a lens of power –5.5 dioptres for correcting distant vision, for correcting his near vision he needs a lens of power +1.5 dioptre. What is the focal length of the lens required and lens type required for correcting 1. distant vision, 2. near vision. [3 MARKS]
Answer» A person needs a lens of power –5.5 dioptres for correcting distant vision, for correcting his near vision he needs a lens of power +1.5 dioptre. What is the focal length of the lens required and lens type required for correcting 1. distant vision, 2. near vision. [3 MARKS]

Discussion

18.	ntA convex lens made up of glass of refractive index 1.5 is dipped , in turn , inn nti) a medium of refractive index 1.65n ntii) a medium of of refractive index 1.33n nt a)will it behave as refracting lens in the 2 cases? Explainn nt b)How will its focal length change in the 2 media?n
Answer» ntA convex lens made up of glass of refractive index 1.5 is dipped , in turn , inn nti) a medium of refractive index 1.65n ntii) a medium of of refractive index 1.33n nt a)will it behave as refracting lens in the 2 cases? Explainn nt b)How will its focal length change in the 2 media?n

Discussion

19.	A pendulum of mass m kg has velocity v at point A. What is the change in potential energy when the pendulum reaches point B as shown in figure ?
Answer» A pendulum of mass $m kg$ has velocity $v$ at point $A$ . What is the change in potential energy when the pendulum reaches point $B$ as shown in figure ?

Discussion

20.	The angle between the two vectors →A=3^i+4^j+5^k and →B=3^i+4^j−5^k will be
Answer» The angle between the two vectors $\to A = 3^i + 4^j + 5^k$ and $\to B = 3^i + 4^j - 5^k$ will be

Discussion

21.	a charge Q is distributed uniformly within the material of a hollow sphere of inner and outer radii r1 and r2 respectively. Draw a rough graph showing the electric field as a function of x for 0
Answer» a charge Q is distributed uniformly within the material of a hollow sphere of inner and outer radii r1 and r2 respectively. Draw a rough graph showing the electric field as a function of x for 0

Discussion

22.	the ratio of maximum velocity to the velocity od of a particle performing S.H.M at a point where potential energy is 25% of total energ
Answer» the ratio of maximum velocity to the velocity od of a particle performing S.H.M at a point where potential energy is 25% of total energ

Discussion

23.	A potential difference of 6 V is applied across a conductor of length 0.12 m. The drift velocity of an electron is[mobility of electron=5.6×10−6 m2/Vs]
Answer» A potential difference of $6 V$ is applied across a conductor of length $0.12 m$ . The drift velocity of an electron is $[$ mobility of electron $= 5.6 \times 10^{- 6} m^{2} /Vs]$

Discussion

24.	An open cubical tank was initially fully filled with water. When the tank was accelerated on a horizontal plane along one of its side it was found that one -third of volume of water spilled out . The acceleration was : A) g/3 B) 2g/3 C) 3g/2 D) none of these
Answer» An open cubical tank was initially fully filled with water. When the tank was accelerated on a horizontal plane along one of its side it was found that one -third of volume of water spilled out . The acceleration was : A) g/3 B) 2g/3 C) 3g/2 D) none of these

Discussion

25.	A given coin has a mass of 3.0 g. Calculate the nuclear energy thatwould be required to separate all the neutrons and protons fromeach other. For simplicity assume that the coin is entirely made of6329Cu atoms (of mass 62.92960 u).
Answer» A given coin has a mass of 3.0 g. Calculate the nuclear energy thatwould be required to separate all the neutrons and protons fromeach other. For simplicity assume that the coin is entirely made of6329Cu atoms (of mass 62.92960 u).

Discussion

26.	The length of a simple pendulum is increased by 44%. What is the percentage increase in its time period?
Answer» The length of a simple pendulum is increased by $44 %$ . What is the percentage increase in its time period?

Discussion

27.	The length of an elastic string is X m when the tension is 8 N and Y m when the tension is 10 N.The length in meters when the tension will be 18 N , will be what?
Answer» The length of an elastic string is X m when the tension is 8 N and Y m when the tension is 10 N.The length in meters when the tension will be 18 N , will be what?

Discussion

28.	In an intrinsic semiconductor the energy gap Eg is 1.2eV. Its holemobility is much smaller than electron mobility and independent oftemperature. What is the ratio between conductivity at 600K andthat at 300K? Assume that the temperature dependence of intrinsiccarrier concentration ni is given byni=n0exp(-Eg/2kBT) where n0is a constant.
Answer» In an intrinsic semiconductor the energy gap Eg is 1.2eV. Its holemobility is much smaller than electron mobility and independent oftemperature. What is the ratio between conductivity at 600K andthat at 300K? Assume that the temperature dependence of intrinsiccarrier concentration ni is given byni=n0exp(-Eg/2kBT) where n0is a constant.

Discussion

29.	What is the role of a split ring in an electric motor? [3 MARKS]
Answer» What is the role of a split ring in an electric motor? [3 MARKS]

Discussion

30.	Aconducting sphere of radius 10 cm has an unknown charge. If theelectric field 20 cm from the centre of the sphere is 1.5 × 103N/C and points radially inward,what is the net charge on the sphere?
Answer» A conducting sphere of radius 10 cm has an unknown charge. If the electric field 20 cm from the centre of the sphere is 1.5 × 10³N/C and points radially inward, what is the net charge on the sphere?

Discussion

31.	energy of 1 mole of photons each having wavelength 300 nm will be ?if h=6.625×10 raise to -34 J
Answer» energy of 1 mole of photons each having wavelength 300 nm will be ?if h=6.625×10 raise to -34 J

Discussion

32.	A body falls from height h.The v-s graph is?
Answer» A body falls from height h.The v-s graph is?

Discussion

33.	52. The minimum stopping distance of a car moving with no velocity v is x. If the car is moving with velocity 2v then the minimum stopping distance will be
Answer» 52. The minimum stopping distance of a car moving with no velocity v is x. If the car is moving with velocity 2v then the minimum stopping distance will be

Discussion

34.	A square plate of 0.1 m side moves parallel to a second plate with a relative velocity of 0.1 m/s, both plates being immersed in water. If the viscous force is 0.002 N and the coefficient of viscosity is 0.01 Poise, distance between the plates in m is
Answer» A square plate of $0.1 m$ side moves parallel to a second plate with a relative velocity of $0.1 m/s$ , both plates being immersed in water. If the viscous force is $0.002 N$ and the coefficient of viscosity is $0.01 Poise$ , distance between the plates in $m$ is

Discussion

35.	what is the order of electronegativity in boron famil
Answer» what is the order of electronegativity in boron famil

Discussion

36.	A machine gun fires a bullet of mass 40 g with a velocity 1200 m/s. The man holding it can exert a maximum force of 144 N on the gun. How many bullets can be fired per second at most?
Answer» A machine gun fires a bullet of mass $40 g$ with a velocity $1200 m/s$ . The man holding it can exert a maximum force of $144 N$ on the gun. How many bullets can be fired per second at most?

Discussion

37.	A 2 kg mass M slides from rest at A along the frictionless rod bent into an elliptical shape. The spring with spring constant k=17.5 N/m has an unstretched length of 450 mm. Determine the speed of M at B. (Answer upto two decimal places]
Answer» A $2 kg$ mass $M$ slides from rest at $A$ along the frictionless rod bent into an elliptical shape. The spring with spring constant $k = 17.5 N/m$ has an unstretched length of $450 mm$ . Determine the speed of $M$ at $B$ . (Answer upto two decimal places]

Discussion

38.	If a bullet of mass 5 gm moving with velocity 100 m /sec, penetrates the wooden block upto 6 cm. Then the average force imposed by the bullet on the block is
Answer» If a bullet of mass 5 gm moving with velocity 100 m /sec, penetrates the wooden block upto 6 cm. Then the average force imposed by the bullet on the block is

Discussion

39.	In an electric iron heat produced is same, whether it is connected across an A.C. source or across 50 Vconstant voltage. R.M.S. value of the A.C. voltage applied is
Answer» In an electric iron heat produced is same, whether it is connected across an A.C. source or across 50 Vconstant voltage. R.M.S. value of the A.C. voltage applied is

Discussion

40.	Which of the following do not depend on the frame of reference?1. Mass2. Distance between two points3. Velocity4. 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

41.	31. A meter stick is held vertically with one end on the floor and is allowed too fall. The speed of the other endwhen it hits the floor assuming that the end at the floor does not slip is (g 9.8 m/s2)(3) 7.6 m/s(1) 3.2 m/s(2) 5.4 m/s(4) 9.2 m/s
Answer» 31. A meter stick is held vertically with one end on the floor and is allowed too fall. The speed of the other end when it hits the floor assuming that the end at the floor does not slip is (g 9.8 m/s2) (3) 7.6 m/s (1) 3.2 m/s (2) 5.4 m/s (4) 9.2 m/s

Discussion

42.	For a Physics project, a student requires a 4 μF capacitor in a circuit across a potential difference of 1 kV. Unfortunately, 4 μF capacitors are out of stock in the lab. However, 2 μF capacitors which can withstand a potential difference of 400 V are available in plenty. Find the minimum number of capacitors required.
Answer» For a Physics project, a student requires a $4 μ F$ capacitor in a circuit across a potential difference of 1 kV. Unfortunately, $4 μ F$ capacitors are out of stock in the lab. However, $2 μ F$ capacitors which can withstand a potential difference of 400 V are available in plenty. Find the minimum number of capacitors required.

Discussion

43.	How to find the acceleration of center of mass of atwoods machine when the lighter body rises up with an acceleration a?
Answer» How to find the acceleration of center of mass of atwoods machine when the lighter body rises up with an acceleration a?

Discussion

44.	The percentage errors in a, b, c are ±1%,±3% and ±2%respectively. The percentage error in x=ab2c3 can be
Answer» The percentage errors in a, b, c are $\pm 1 %, \pm 3 %$ and $\pm 2 %$ respectively. The percentage error in $x = \frac{a b^{2}}{c^{3}}$ can be

Discussion

45.	An atom crystallizes in a fcc unit cell having radius of 100√2 pm.Calculate the distance between the two tetrahedral voids which are formed on a same body diagonal
Answer» An atom crystallizes in a fcc unit cell having radius of $100 \sqrt{2} p m$ . Calculate the distance between the two tetrahedral voids which are formed on a same body diagonal

Discussion

46.	Explain whether Gauss's law is useful in calculating the electric field due to three equal charges located at the corners of an equilateral triangle.
Answer» Explain whether Gauss's law is useful in calculating the electric field due to three equal charges located at the corners of an equilateral triangle.

Discussion

47.	In the figure shown is a parallel beam of white light incident on the plane of the slits. The distance of the nearest white spot on the screen from O is : [ assume d<<D,λ<<d]
Answer» In the figure shown is a parallel beam of white light incident on the plane of the slits. The distance of the nearest white spot on the screen from $O$ is : [ assume $d << D, λ << d$ ]

Discussion

48.	Anelectron emitted by a heated cathode and accelerated through apotential difference of 2.0 kV, enters a region with uniform magneticfield of 0.15 T. Determine the trajectory of the electron if thefield (a) is transverse to its initial velocity, (b) makes an angleof 30º with the initial velocity.
Answer» An electron emitted by a heated cathode and accelerated through a potential difference of 2.0 kV, enters a region with uniform magnetic field of 0.15 T. Determine the trajectory of the electron if the field (a) is transverse to its initial velocity, (b) makes an angle of 30º with the initial velocity.

Discussion

49.	5. Relation between Kf and Kb.( Elevation in freezing point and boiling point)
Answer» 5. Relation between Kf and Kb.( Elevation in freezing point and boiling point)

Discussion

50.	A bullet fired into a fixed target loses half of its velocity after penetrating 3 cm. How much further will it penetrate before coming to rest assuming that it faces constant resistance to motion?
Answer» A bullet fired into a fixed target loses half of its velocity after penetrating $3 c m$ . How much further will it penetrate before coming to rest assuming that it faces constant resistance to motion?

Discussion

Explore topic-wise InterviewSolutions in Current Affairs.

Explain the difference between resistance and resistivity.

Who discovered the cathode rays ?

Shown in the figure, is a hollow ice-cream cone (it is open at the top). If its mass is M, radius of its top is R and height H then, its moment of inertia about its axis is:

Motional emf in straight conductor

An observer stands at a distance of 850 m from the cliff and fires a gun. After what time gap will he hear the echo, if sound travels at a speed of 350ms−1 in air?

If position x as a function of time t is given as x=t^3+2t^2 then acceleration at t=2 seconds is (x in metres)

(a) At what distance should the lens be held from the figure in Exercise 9.29 in order to view the squares distinctly with the maximum possible magnifying power? (b) What is the magnification in this case? (c) Is the magnification equal to the magnifying power in this case? Explain.

Derives=vt-1\2(at²)

A parallel beam of light of wavelength 600 nm is incident normally on a slit of width d. If the distance between the slits and the screen is 0.8 m and the distance of 2nd order maximum from the center of the screen is 15 mm, the width of the slit is,

In a lake 2m deep, a measuring post of height 3m is fixed vertically. For an angle of incidence of 30° of Sun’s radiations, find the length of the shadow of the post at the bottom surface?(μw = 4/3)

Through the oil drop experiment, how did Millikan calculate the charge of an electron?

A person needs a lens of power –5.5 dioptres for correcting distant vision, for correcting his near vision he needs a lens of power +1.5 dioptre. What is the focal length of the lens required and lens type required for correcting 1. distant vision, 2. near vision. [3 MARKS]

ntA convex lens made up of glass of refractive index 1.5 is dipped , in turn , inn nti) a medium of refractive index 1.65n ntii) a medium of of refractive index 1.33n nt a)will it behave as refracting lens in the 2 cases? Explainn nt b)How will its focal length change in the 2 media?n

A pendulum of mass m kg has velocity v at point A. What is the change in potential energy when the pendulum reaches point B as shown in figure ?

The angle between the two vectors →A=3^i+4^j+5^k and →B=3^i+4^j−5^k will be

a charge Q is distributed uniformly within the material of a hollow sphere of inner and outer radii r1 and r2 respectively. Draw a rough graph showing the electric field as a function of x for 0

the ratio of maximum velocity to the velocity od of a particle performing S.H.M at a point where potential energy is 25% of total energ

A potential difference of 6 V is applied across a conductor of length 0.12 m. The drift velocity of an electron is[mobility of electron=5.6×10−6 m2/Vs]

An open cubical tank was initially fully filled with water. When the tank was accelerated on a horizontal plane along one of its side it was found that one -third of volume of water spilled out . The acceleration was : A) g/3 B) 2g/3 C) 3g/2 D) none of these

A given coin has a mass of 3.0 g. Calculate the nuclear energy thatwould be required to separate all the neutrons and protons fromeach other. For simplicity assume that the coin is entirely made of6329Cu atoms (of mass 62.92960 u).

The length of a simple pendulum is increased by 44%. What is the percentage increase in its time period?

The length of an elastic string is X m when the tension is 8 N and Y m when the tension is 10 N.The length in meters when the tension will be 18 N , will be what?

What is the role of a split ring in an electric motor? [3 MARKS]

Aconducting sphere of radius 10 cm has an unknown charge. If theelectric field 20 cm from the centre of the sphere is 1.5 × 103N/C and points radially inward,what is the net charge on the sphere?

energy of 1 mole of photons each having wavelength 300 nm will be ?if h=6.625×10 raise to -34 J

A body falls from height h.The v-s graph is?

52. The minimum stopping distance of a car moving with no velocity v is x. If the car is moving with velocity 2v then the minimum stopping distance will be

A square plate of 0.1 m side moves parallel to a second plate with a relative velocity of 0.1 m/s, both plates being immersed in water. If the viscous force is 0.002 N and the coefficient of viscosity is 0.01 Poise, distance between the plates in m is

what is the order of electronegativity in boron famil

A machine gun fires a bullet of mass 40 g with a velocity 1200 m/s. The man holding it can exert a maximum force of 144 N on the gun. How many bullets can be fired per second at most?

A 2 kg mass M slides from rest at A along the frictionless rod bent into an elliptical shape. The spring with spring constant k=17.5 N/m has an unstretched length of 450 mm. Determine the speed of M at B. (Answer upto two decimal places]​​​

If a bullet of mass 5 gm moving with velocity 100 m /sec, penetrates the wooden block upto 6 cm. Then the average force imposed by the bullet on the block is

In an electric iron heat produced is same, whether it is connected across an A.C. source or across 50 Vconstant voltage. R.M.S. value of the A.C. voltage applied is

Which of the following do not depend on the frame of reference?1. Mass2. Distance between two points3. Velocity4. Distance

31. A meter stick is held vertically with one end on the floor and is allowed too fall. The speed of the other endwhen it hits the floor assuming that the end at the floor does not slip is (g 9.8 m/s2)(3) 7.6 m/s(1) 3.2 m/s(2) 5.4 m/s(4) 9.2 m/s

How to find the acceleration of center of mass of atwoods machine when the lighter body rises up with an acceleration a?

The percentage errors in a, b, c are ±1%,±3% and ±2%respectively. The percentage error in x=ab2c3 can be

An atom crystallizes in a fcc unit cell having radius of 100√2 pm.Calculate the distance between the two tetrahedral voids which are formed on a same body diagonal

Explain whether Gauss's law is useful in calculating the electric field due to three equal charges located at the corners of an equilateral triangle.

In the figure shown is a parallel beam of white light incident on the plane of the slits. The distance of the nearest white spot on the screen from O is : [ assume d&lt;&lt;D,λ&lt;&lt;d]

Anelectron emitted by a heated cathode and accelerated through apotential difference of 2.0 kV, enters a region with uniform magneticfield of 0.15 T. Determine the trajectory of the electron if thefield (a) is transverse to its initial velocity, (b) makes an angleof 30º with the initial velocity.

5. Relation between Kf and Kb.( Elevation in freezing point and boiling point)

A bullet fired into a fixed target loses half of its velocity after penetrating 3 cm. How much further will it penetrate before coming to rest assuming that it faces constant resistance to motion?

A 2 kg mass M slides from rest at A along the frictionless rod bent into an elliptical shape. The spring with spring constant k=17.5 N/m has an unstretched length of 450 mm. Determine the speed of M at B. (Answer upto two decimal places]

In the figure shown is a parallel beam of white light incident on the plane of the slits. The distance of the nearest white spot on the screen from O is : [ assume d<<D,λ<<d]