50278 + Interview Questions in Physics

1.	Kepler's second law regarding constancy of aerial velocity of a planet is a consequence of the law of conservation of
Answer» Kepler's second law regarding constancy of aerial velocity of a planet is a consequence of the law of conservation of

Discussion

2.	The ratio of the energy of a photon with λ=150 nm to that with λ=300 nm is
Answer» The ratio of the energy of a photon with $λ = 150 n m$ to that with $λ = 300 n m$ is

Discussion

3.	A mass m slips along a smooth hemispherical surface of radius R starting from rest at the top as shown. The velocity of the mass at the bottom of the surface is
Answer» A mass m slips along a smooth hemispherical surface of radius R starting from rest at the top as shown. The velocity of the mass at the bottom of the surface is

3.

A mass m slips along a smooth hemispherical surface of radius R starting from rest at the top as shown. The velocity of the mass at the bottom of the surface is

Answer»

A mass m slips along a smooth hemispherical surface of radius R starting from rest at the top as shown.

The velocity of the mass at the bottom of the surface is

Discussion

4.	Body shown in figure is square aluminium plate of side 0.2 m. When a tangential force of 1×106 N is applied to the top face, the resulting shear strain is 0.01. If modulus of rigidity is η=0.3×1011 N/m2 then thickness of plate is x3 cm. Here x is
Answer» Body shown in figure is square aluminium plate of side 0.2 m. When a tangential force of $1 \times 10^{6} N$ is applied to the top face, the resulting shear strain is 0.01. If modulus of rigidity is $η = 0.3 \times 10^{11} N / m^{2}$ then thickness of plate is $\frac{x}{3}$ cm. Here $x$ is

Discussion

5.	228Th emits an alpha particle to reduce to 224Ra. Calculate the kinetic energy of the alpha particle emitted in the following decay: 228Th→224Ra∗+α 224Ra∗→224Ra+γ(217keV)
Answer» $^{228} Th$ emits an alpha particle to reduce to $^{224} Ra$ . Calculate the kinetic energy of the alpha particle emitted in the following decay: $^{228} Th \to^{224} {Ra}^{} + α$ $^{224} {Ra}^{} \to^{224} Ra + γ (217 keV)$

5.

228Th emits an alpha particle to reduce to 224Ra. Calculate the kinetic energy of the alpha particle emitted in the following decay: 228Th→224Ra∗+α 224Ra∗→224Ra+γ(217keV)

Answer»

$^{228} Th$ emits an alpha particle to reduce to $^{224} Ra$ . Calculate the kinetic energy of the alpha particle emitted in the following decay:

$^{228} Th \to^{224} {Ra}^{*} + α$

$^{224} {Ra}^{*} \to^{224} Ra + γ (217 keV)$

Discussion

6.	An infinite number of charges of equal magnitude q, but of opposite sign are placed alternately starting with positive charge along x- axis at x = 1 m; x = 2 m,x = 4 m, x= 8 m and so on. The electric potential at the point x = 0 due to these charges will be (in S.I units and k = 14πϵ0
Answer» An infinite number of charges of equal magnitude q, but of opposite sign are placed alternately starting with positive charge along x- axis at x = 1 m; x = 2 m,x = 4 m, x= 8 m and so on. The electric potential at the point x = 0 due to these charges will be (in S.I units and k = $\frac{1}{4 π ϵ_{0}}$

Discussion

7.	If the tension of sonometer's wire increases four times then the fundamental frequency of the wire will increase by [RPMT 1999]
Answer» If the tension of sonometer's wire increases four times then the fundamental frequency of the wire will increase by [RPMT 1999]

7.

If the tension of sonometer's wire increases four times then the fundamental frequency of the wire will increase by [RPMT 1999]

Answer»

If the tension of sonometer's wire increases four times then the fundamental frequency of the wire will increase by

[RPMT 1999]

Discussion

8.	The sum of the magnitudes of two forces acting at a point is 18 and the magnitude of their resultant is 12. If the resultant is at 90° with the force of smaller magnitude, what are the magnitudes of forces?
Answer» The sum of the magnitudes of two forces acting at a point is 18 and the magnitude of their resultant is 12. If the resultant is at 90° with the force of smaller magnitude, what are the magnitudes of forces?

Discussion

9.	Magnetic dipole moment of given star if each side of it is of length a is given as 3na2 i, Then n is(up to two decimal places)
Answer» Magnetic dipole moment of given star if each side of it is of length a is given as $3 n a^{2}$ i, Then n is(up to two decimal places)

Discussion

10.	A frictionless track has a curve of radius 90√3 m. If the speed limit on this road is 30 m/s, what should be the banking angle for this road to ensure safe driving ? Take g=10 m/s2.
Answer» A frictionless track has a curve of radius $90 \sqrt{3} m$ . If the speed limit on this road is $30 m/s$ , what should be the banking angle for this road to ensure safe driving ? Take $g = 10 {m/s}^{2}$ .

Discussion

11.	Two masses M1 and M2 are connected by a light rod and the system is slipping down a rough incline of angle θ with the horizontal. The friction coefficient at both the contacts is μ. Find the acceleration of teh system and the force by the rod on one of the blocks.
Answer» Two masses $M_{1}$ and $M_{2}$ are connected by a light rod and the system is slipping down a rough incline of angle $θ$ with the horizontal. The friction coefficient at both the contacts is $μ .$ Find the acceleration of teh system and the force by the rod on one of the blocks.

Discussion

12.	In a radioactive sample the decrease in the number of active nuclei at any time is directly proportional to?
Answer» In a radioactive sample the decrease in the number of active nuclei at any time is directly proportional to?

Discussion

13.	When a point source of light is at a distance of 50 cm from a photoelectric cell, the cut off voltage is found to be V0. If the same source is placed at a distance of 1 m from the cell, the cut off voltage will be
Answer» When a point source of light is at a distance of 50 cm from a photoelectric cell, the cut off voltage is found to be $V_{0}$ . If the same source is placed at a distance of 1 m from the cell, the cut off voltage will be

Discussion

14.	One quarter section is cut from a uniform circular disc of radius R. This section has a mass M. It is made to rotate about a line perpendicular to its plane and passing through the centre of the original disc. Its moment of inertia about the axis of rotation is
Answer» One quarter section is cut from a uniform circular disc of radius R. This section has a mass M. It is made to rotate about a line perpendicular to its plane and passing through the centre of the original disc. Its moment of inertia about the axis of rotation is

14.

One quarter section is cut from a uniform circular disc of radius R. This section has a mass M. It is made to rotate about a line perpendicular to its plane and passing through the centre of the original disc. Its moment of inertia about the axis of rotation is

Answer»

One quarter section is cut from a uniform circular disc of radius R. This section has a mass M. It is made to rotate about a line perpendicular to its plane and passing through the centre of the original disc. Its moment of inertia about the axis of rotation is

Discussion

15.	If kinetic energy of a body is increased by 300%, then percentage change in momentum will be
Answer» If kinetic energy of a body is increased by 300%, then percentage change in momentum will be

15.

If kinetic energy of a body is increased by 300%, then percentage change in momentum will be

Answer»

If kinetic energy of a body is increased by 300%, then percentage change in momentum will be

Discussion

16.	A galvanometer gives full scale deflection with 0.006 A current. By connecting it to a 4990 Ω resistance, it can be converted into a voltmeter of range 0 – 30 V. If connected to a 2n249Ω a resistance, it becomes an ammeter of range 0 – 1.5 A. The value of n is
Answer» A galvanometer gives full scale deflection with 0.006 A current. By connecting it to a 4990 $Ω$ resistance, it can be converted into a voltmeter of range 0 – 30 V. If connected to a $\frac{2 n}{249} Ω$ a resistance, it becomes an ammeter of range 0 – 1.5 A. The value of n is

Discussion

17.	In the following displacement (x) vs. time (t) graph, at which point is the object's speed increasing?
Answer» In the following displacement (x) vs. time (t) graph, at which point is the object's speed increasing?

17.

In the following displacement (x) vs. time (t) graph, at which point is the object's speed increasing?

Answer»

In the following displacement (x) vs. time (t) graph, at which point is the object's speed increasing?

Discussion

18.	If the ring performs combined rotational and translational motion on a frictionless horizontal surface as shown in figure, find the magnitude of the velocity at a point P on the ring.
Answer» If the ring performs combined rotational and translational motion on a frictionless horizontal surface as shown in figure, find the magnitude of the velocity at a point $P$ on the ring.

Discussion

19.	If the binding energy per nucleon in 73Li and 42He nuclei are 5.60 MeV and 7.06 MeV respectivley, then in the reaction p+73Li→42He, energy of proton must be
Answer» If the binding energy per nucleon in $\begin{matrix} 73 \end{matrix} L i$ and $\begin{matrix} 42 \end{matrix} H e$ nuclei are 5.60 MeV and 7.06 MeV respectivley, then in the reaction $p + \begin{matrix} 73 \end{matrix} L i \to \begin{matrix} 42 \end{matrix} H e$ , energy of proton must be

Discussion

20.	For the given system, find the extension in the spring if m1=4 kg and m2=6 kg. Take g=10 m/s2.
Answer» For the given system, find the extension in the spring if $m_{1} = 4 kg$ and $m_{2} = 6 kg$ . Take $g = 10 {m/s}^{2}$ .

Discussion

21.	Why does a body weigh more at the poles than at the equator?
Answer» Why does a body weigh more at the poles than at the equator?

Discussion

22.	at macroscopic level the quantisation of charge has no practical consequences and can be ignored-why?
Answer» at macroscopic level the quantisation of charge has no practical consequences and can be ignored-why?

Discussion

23.	What is the dimensional formula of angular momentum L ? L=r p sinθ, where r is the position and P is momentum.
Answer» What is the dimensional formula of angular momentum $L$ ? $L = r p sin θ$ , where $r$ is the position and $P$ is momentum.

Discussion

24.	A wire of resistance 10 ohm is elongated by 10%. The resistance of the elongated wire is
Answer» A wire of resistance 10 ohm is elongated by 10%. The resistance of the elongated wire is

Discussion

25.	The negative potential energy of a particle at liquid surface is less than that of a molecule in bulk.Then why is it said that they have extra energy than molecules in bulk?
Answer» The negative potential energy of a particle at liquid surface is less than that of a molecule in bulk.Then why is it said that they have extra energy than molecules in bulk?

Discussion

26.	A vessel of area of cross-section A has liquid upto a height H. A hole is made in the wall of vessel such that water coming out of it travels maximum horizontal distance of 2 m. Find the value of H.
Answer» A vessel of area of cross-section $A$ has liquid upto a height $H$ . A hole is made in the wall of vessel such that water coming out of it travels maximum horizontal distance of $2 m$ . Find the value of $H$ .

Discussion

27.	Find the moment of inertia (MI) of an uniform rod of mass 3 kg and length 2 m about an axis (yy′) perpendicular to the plane of rod and passing through it's one end (A) as shown in the figure.
Answer» Find the moment of inertia ( $MI$ ) of an uniform rod of mass $3 kg$ and length $2 m$ about an axis ( $y y^{'}$ ) perpendicular to the plane of rod and passing through it's one end ( $A$ ) as shown in the figure.

Discussion

28.	I cant get the solution correct to this sum and also help me with tan2100
Answer» I cant get the solution correct to this sum and also help me with tan²100

Discussion

29.	Three forces −→F1=2^i−4^j+5^k, −→F2=^i+3^j−8^k and −→F3=−6^i−10^j+7^k are acting on a particle present on the positive x axis, 5 units away from the origin. The three forces combined displace the body to a point 6ˆi−3ˆj+10ˆk. What is the net work done by the three forces ?
Answer» Three forces $_{1} = 2^i - 4^j + 5^k$ , $_{2} =^i + 3^j - 8^k$ and $_{3} = - 6^i - 10^j + 7^k$ are acting on a particle present on the positive $x$ axis, $5 units$ away from the origin. The three forces combined displace the body to a point $6 ˆ i - 3 ˆ j + 10 ˆ k$ . What is the net work done by the three forces ?

Discussion

30.	A body of mass 1 kg is taken from infinity to a point P. when the body reaches that point,it has a speed of 2m/s. the work done by conservative force is -5J. which of the following is true(assuming non-conservative and pseudo-forces to be absent). a) work done by applied force is +7J. b)the total energy possessed by the body at P is +7J c)The potential energy possessed by the bodyat P is +5J d) work done by all foeces together is equal to the change in KE.
Answer» A body of mass 1 kg is taken from infinity to a point P. when the body reaches that point,it has a speed of 2m/s. the work done by conservative force is -5J. which of the following is true(assuming non-conservative and pseudo-forces to be absent). a) work done by applied force is +7J. b)the total energy possessed by the body at P is +7J c)The potential energy possessed by the bodyat P is +5J d) work done by all foeces together is equal to the change in KE.

30.

A body of mass 1 kg is taken from infinity to a point P. when the body reaches that point,it has a speed of 2m/s. the work done by conservative force is -5J. which of the following is true(assuming non-conservative and pseudo-forces to be absent). a) work done by applied force is +7J. b)the total energy possessed by the body at P is +7J c)The potential energy possessed by the bodyat P is +5J d) work done by all foeces together is equal to the change in KE.

Answer»

A body of mass 1 kg is taken from infinity to a point P. when the body reaches that point,it has a speed of 2m/s. the work done by conservative force is -5J. which of the following is true(assuming non-conservative and pseudo-forces to be absent).

a) work done by applied force is +7J.

b)the total energy possessed by the body at P is +7J

c)The potential energy possessed by the bodyat P is +5J

d) work done by all foeces together is equal to the change in KE.

Discussion

31.	A conservative force of magnitude 100 N directed along the line y=3+x is acting on a block of mass m=1 kg. Find work done (in J) by given force, when block displaces from point A(3,1) to point B (1,3)
Answer» A conservative force of magnitude $100 N$ directed along the line $y = 3 + x$ is acting on a block of mass $m = 1$ kg. Find work done (in J) by given force, when block displaces from point $A (3, 1)$ to point B $(1, 3)$

Discussion

32.	A ball rolls horizontally off the top of a stairway with a speed of 1.5 ms−1. The steps are 0.2 m high and 0.2 m wide. If the balls hits the edge of nth step first, then n is equal to
Answer» A ball rolls horizontally off the top of a stairway with a speed of $1.5 {ms}^{- 1}$ . The steps are $0.2 m$ high and $0.2 m$ wide. If the balls hits the edge of $n^{t h}$ step first, then $n$ is equal to

Discussion

33.	Two satellites of masses 3m and m orbit the earth in circular orbits of radii r and 3r respectively. The ratio of their orbital speeds is
Answer» Two satellites of masses 3m and m orbit the earth in circular orbits of radii r and 3r respectively. The ratio of their orbital speeds is

Discussion

34.	If f be a function defined on an interval I and there exists a point “a” in I such that f(a) ≥ f(x) for all x ∈ I , then
Answer» If f be a function defined on an interval I and there exists a point “a” in I such that f(a) $\geq$ f(x) for all x $\in$ I , then

Discussion

35.	The de-Broglie wavelength λ
Answer» The de-Broglie wavelength $λ$

Discussion

36.	The point of contact of the tangent to the curve y=√x−1 , having a slope of 13 is
Answer» The point of contact of the tangent to the curve $y = \sqrt{x - 1}$ , having a slope of $\frac{1}{3}$ is

Discussion

37.	A metal rod of cross sectional area 1.0 cm2 is being heated at one end. At one time, the temperature gradient is 5.0∘Ccm−1 at cross section A and is 2.5∘Ccm−1 at cross section B. Calculate the rate at which the emperature is increasing in the part AB of the rod. The heat capacity of the part AB=0.40J∘C−1, thermal conductivity of the material of the rod = 200Wm−1∘C−1. Neglect any loss of heat to the atmosphere.
Answer» A metal rod of cross sectional area 1.0 $c m^{2}$ is being heated at one end. At one time, the temperature gradient is ${5.0}^{\circ} C c m^{- 1}$ at cross section A and is ${2.5}^{\circ} C c m^{- 1}$ at cross section B. Calculate the rate at which the emperature is increasing in the part AB of the rod. The heat capacity of the part $A B = 0.40 J^{\circ} C^{- 1}$ , thermal conductivity of the material of the rod = $200 W m^{- 1 \circ} C^{- 1}$ . Neglect any loss of heat to the atmosphere.

Discussion

38.	Two rectangular blocks A and B of different metals have same length and same area of cross-section. They are kept in such a way that their cross-sectional area touch each other. The temperature at one end of A is 100∘C and that of B at the other end is 0∘C. If the ratio of their thermal conductivity is 1 : 3, then under steady state, the temperature of the junction in contact will be
Answer» Two rectangular blocks A and B of different metals have same length and same area of cross-section. They are kept in such a way that their cross-sectional area touch each other. The temperature at one end of A is $100^{\circ} C$ and that of B at the other end is $0^{\circ} C$ . If the ratio of their thermal conductivity is 1 : 3, then under steady state, the temperature of the junction in contact will be

38.

Two rectangular blocks A and B of different metals have same length and same area of cross-section. They are kept in such a way that their cross-sectional area touch each other. The temperature at one end of A is 100∘C and that of B at the other end is 0∘C. If the ratio of their thermal conductivity is 1 : 3, then under steady state, the temperature of the junction in contact will be

Answer»

Two rectangular blocks A and B of different metals have same length and same area of cross-section. They are kept in such a way that their cross-sectional area touch each other. The temperature at one end of A is $100^{\circ} C$ and that of B at the other end is $0^{\circ} C$ . If the ratio of their thermal conductivity is 1 : 3, then under steady state, the temperature of the junction in contact will be

Discussion

39.	A 2 kg object is subjected to three forces that give it an acceleration →a=−(8^i)m/s2. If two of the three forces are →F1=(30^i+16^j)N and →F2=(−12^i+8^j)N, find the third force (in N).
Answer» A $2 kg$ object is subjected to three forces that give it an acceleration $\to a = - (8^i) {m/s}^{2}$ . If two of the three forces are ${\to F}_{1} = (30^i + 16^j) N$ and ${\to F}_{2} = (- 12^i + 8^j) N$ , find the third force ( $in N$ ).

Discussion

40.	A body is moving with a velocity 5 m/s and an acceleration of 10 m/s2. Which of these are correct?
Answer» A body is moving with a velocity 5 m/s and an acceleration of 10 m/ $s^{2}$ . Which of these are correct?

Discussion

41.	A turn of radius 20 m is banked for the vehicle of mass 200 kg going at a speed of 10 m/s. The minimum coefficient of static friction required, if the vehicle moves with a speed of 15m/s is given by N8. Then, N is [Take g=10 m/s2]
Answer» A turn of radius $20 m$ is banked for the vehicle of mass $200 kg$ going at a speed of $10 m/s$ . The minimum coefficient of static friction required, if the vehicle moves with a speed of $15 m/s$ is given by $\frac{N}{8}$ . Then, $N$ is [Take $g = 10 {m/s}^{2}$ ]

Discussion

42.	A pendulum clock loses 12 seconds a day if the temperature is 40∘C and goes fast by 4 seconds a day if the temperature is 20∘C. Find the temperature at which the clock will show correct time, and the coefficient of linear expansion of the metal of the pendulum shaft.
Answer» A pendulum clock loses 12 seconds a day if the temperature is $40^{\circ} C$ and goes fast by 4 seconds a day if the temperature is $20^{\circ} C$ . Find the temperature at which the clock will show correct time, and the coefficient of linear expansion of the metal of the pendulum shaft.

Discussion

43.	A potential difference of 600 V is applied across the plates of a parallel plate capacitor. The separation between the plates is 3 mm. An electron projected vertically, parallel to the plates, with a velocity of 2×106 ms−1 moves undeflected between the plates. What is the magnitude of the magnetic field between the capacitor plates?
Answer» A potential difference of 600 V is applied across the plates of a parallel plate capacitor. The separation between the plates is 3 mm. An electron projected vertically, parallel to the plates, with a velocity of $2 \times 10^{6} m s^{- 1}$ moves undeflected between the plates. What is the magnitude of the magnetic field between the capacitor plates?

Discussion

44.	A bullet of mass 0.012 kg and horizontal speed 70 ms−1 strikes a block of wood of mass 0.4 kg and instantly comes to rest with respect to the block. The block is suspended from the ceiling by means of thin wires. Calculate the height to which the block rises. Also, estimate the amount of heat produced in the block.
Answer» A bullet of mass 0.012 kg and horizontal speed $70 m s^{- 1}$ strikes a block of wood of mass 0.4 kg and instantly comes to rest with respect to the block. The block is suspended from the ceiling by means of thin wires. Calculate the height to which the block rises. Also, estimate the amount of heat produced in the block.

Discussion

45.	The potential energy (in joule) of a body of mass 2 kg moving in the x−y plane is given by U=6x+8y, where the position coordinates x and y are measured in meter. If the body is at rest at point (6m,4m) at time t=0, it will cross the y – axis at time t equal to
Answer» The potential energy (in joule) of a body of mass $2 kg$ moving in the $x - y$ plane is given by $U = 6 x + 8 y$ , where the position coordinates $x$ and $y$ are measured in meter. If the body is at rest at point $(6 m, 4 m)$ at time $t = 0$ , it will cross the y – axis at time $t$ equal to

Discussion

46.	a parcticle has a displacement of 12m towards east and 5m towards north and then 6m vertically upwards. find the magnitude of the sum of these velocities.
Answer» a parcticle has a displacement of 12m towards east and 5m towards north and then 6m vertically upwards. find the magnitude of the sum of these velocities.

Discussion

47.	The L-shaped fish tank shown in the figure is filled with water and is open at the top. If d=5.0 m, what is the ratio of force exerted by the water on face A and face B? (Take g=10 m/s2 and neglect atmospheric pressure)
Answer» The L-shaped fish tank shown in the figure is filled with water and is open at the top. If $d = 5.0 m$ , what is the ratio of force exerted by the water on face A and face B? (Take $g = 10 {m/s}^{2}$ and neglect atmospheric pressure)

Discussion

48.	At t=0, a particle starts from (4,0) and moves towards positive x−axis with speed of v=8t+3 m/s. The final position of the particle as a function of time is
Answer» At $t = 0$ , a particle starts from $(4, 0)$ and moves towards positive $x -$ axis with speed of $v = 8 t + 3 m/s$ . The final position of the particle as a function of time is

Discussion

49.	Four point objects of mass m are located at the corners of a square of side S as shown in the figure below. Determine the moment of inertia of this system about cd as shown in the figure.
Answer» Four point objects of mass $m$ are located at the corners of a square of side $S$ as shown in the figure below. Determine the moment of inertia of this system about $cd$ as shown in the figure.

Discussion

50.	The energy levels of a hypothetical one electron atom is given by En=−18.0n2eV where n = 1,2,3,..... Find the wavelength which will not be emitted when these atoms in the ground state are bombarded by electrons that have been accelerated through a potential difference of 16.2 V.
Answer» The energy levels of a hypothetical one electron atom is given by $E_{n} = \frac{- 18.0}{n^{2}} e V$ where n = 1,2,3,..... Find the wavelength which will not be emitted when these atoms in the ground state are bombarded by electrons that have been accelerated through a potential difference of 16.2 V.

Discussion

Explore topic-wise InterviewSolutions in Current Affairs.

Kepler's second law regarding constancy of aerial velocity of a planet is a consequence of the law of conservation of

The ratio of the energy of a photon with λ=150 nm to that with λ=300 nm is

A mass m slips along a smooth hemispherical surface of radius R starting from rest at the top as shown. The velocity of the mass at the bottom of the surface is

Body shown in figure is square aluminium plate of side 0.2 m. When a tangential force of 1×106 N is applied to the top face, the resulting shear strain is 0.01. If modulus of rigidity is η=0.3×1011 N/m2 then thickness of plate is x3 cm. Here x is

228Th emits an alpha particle to reduce to 224Ra. Calculate the kinetic energy of the alpha particle emitted in the following decay: 228Th→224Ra∗+α 224Ra∗→224Ra+γ(217keV)

An infinite number of charges of equal magnitude q, but of opposite sign are placed alternately starting with positive charge along x- axis at x = 1 m; x = 2 m,x = 4 m, x= 8 m and so on. The electric potential at the point x = 0 due to these charges will be (in S.I units and k = 14πϵ0

If the tension of sonometer's wire increases four times then the fundamental frequency of the wire will increase by [RPMT 1999]

The sum of the magnitudes of two forces acting at a point is 18 and the magnitude of their resultant is 12. If the resultant is at 90° with the force of smaller magnitude, what are the magnitudes of forces?

Magnetic dipole moment of given star if each side of it is of length a is given as 3na2 i, Then n is(up to two decimal places)

A frictionless track has a curve of radius 90√3 m. If the speed limit on this road is 30 m/s, what should be the banking angle for this road to ensure safe driving ? Take g=10 m/s2.

Two masses M1 and M2 are connected by a light rod and the system is slipping down a rough incline of angle θ with the horizontal. The friction coefficient at both the contacts is μ. Find the acceleration of teh system and the force by the rod on one of the blocks.

In a radioactive sample the decrease in the number of active nuclei at any time is directly proportional to?

When a point source of light is at a distance of 50 cm from a photoelectric cell, the cut off voltage is found to be V0. If the same source is placed at a distance of 1 m from the cell, the cut off voltage will be

One quarter section is cut from a uniform circular disc of radius R. This section has a mass M. It is made to rotate about a line perpendicular to its plane and passing through the centre of the original disc. Its moment of inertia about the axis of rotation is

If kinetic energy of a body is increased by 300%, then percentage change in momentum will be

A galvanometer gives full scale deflection with 0.006 A current. By connecting it to a 4990 Ω resistance, it can be converted into a voltmeter of range 0 – 30 V. If connected to a 2n249Ω a resistance, it becomes an ammeter of range 0 – 1.5 A. The value of n is

In the following displacement (x) vs. time (t) graph, at which point is the object's speed increasing?

If the ring performs combined rotational and translational motion on a frictionless horizontal surface as shown in figure, find the magnitude of the velocity at a point P on the ring.

If the binding energy per nucleon in 73Li and 42He nuclei are 5.60 MeV and 7.06 MeV respectivley, then in the reaction p+73Li→42He, energy of proton must be

For the given system, find the extension in the spring if m1=4 kg and m2=6 kg. Take g=10 m/s2.

Why does a body weigh more at the poles than at the equator?

at macroscopic level the quantisation of charge has no practical consequences and can be ignored-why?

What is the dimensional formula of angular momentum L ? L=r p sinθ, where r is the position and P is momentum.

A wire of resistance 10 ohm is elongated by 10%. The resistance of the elongated wire is

The negative potential energy of a particle at liquid surface is less than that of a molecule in bulk.Then why is it said that they have extra energy than molecules in bulk?

A vessel of area of cross-section A has liquid upto a height H. A hole is made in the wall of vessel such that water coming out of it travels maximum horizontal distance of 2 m. Find the value of H.

Find the moment of inertia (MI) of an uniform rod of mass 3 kg and length 2 m about an axis (yy′) perpendicular to the plane of rod and passing through it's one end (A) as shown in the figure.

I cant get the solution correct to this sum and also help me with tan2100

Three forces −→F1=2^i−4^j+5^k, −→F2=^i+3^j−8^k and −→F3=−6^i−10^j+7^k are acting on a particle present on the positive x axis, 5 units away from the origin. The three forces combined displace the body to a point 6ˆi−3ˆj+10ˆk. What is the net work done by the three forces ?

A conservative force of magnitude 100 N directed along the line y=3+x is acting on a block of mass m=1 kg. Find work done (in J) by given force, when block displaces from point A(3,1) to point B (1,3)

A ball rolls horizontally off the top of a stairway with a speed of 1.5 ms−1. The steps are 0.2 m high and 0.2 m wide. If the balls hits the edge of nth step first, then n is equal to

Two satellites of masses 3m and m orbit the earth in circular orbits of radii r and 3r respectively. The ratio of their orbital speeds is

If f be a function defined on an interval I and there exists a point “a” in I such that f(a) ≥ f(x) for all x ∈ I , then

The de-Broglie wavelength λ

The point of contact of the tangent to the curve y=√x−1 , having a slope of 13 is

A 2 kg object is subjected to three forces that give it an acceleration →a=−(8^i)m/s2. If two of the three forces are →F1=(30^i+16^j)N and →F2=(−12^i+8^j)N, find the third force (in N).

A body is moving with a velocity 5 m/s and an acceleration of 10 m/s2. Which of these are correct?

A turn of radius 20 m is banked for the vehicle of mass 200 kg going at a speed of 10 m/s. The minimum coefficient of static friction required, if the vehicle moves with a speed of 15m/s is given by N8. Then, N is [Take g=10 m/s2]

A pendulum clock loses 12 seconds a day if the temperature is 40∘C and goes fast by 4 seconds a day if the temperature is 20∘C. Find the temperature at which the clock will show correct time, and the coefficient of linear expansion of the metal of the pendulum shaft.

The potential energy (in joule) of a body of mass 2 kg moving in the x−y plane is given by U=6x+8y, where the position coordinates x and y are measured in meter. If the body is at rest at point (6m,4m) at time t=0, it will cross the y – axis at time t equal to

a parcticle has a displacement of 12m towards east and 5m towards north and then 6m vertically upwards. find the magnitude of the sum of these velocities.

The L-shaped fish tank shown in the figure is filled with water and is open at the top. If d=5.0 m, what is the ratio of force exerted by the water on face A and face B? (Take g=10 m/s2 and neglect atmospheric pressure)

At t=0, a particle starts from (4,0) and moves towards positive x−axis with speed of v=8t+3 m/s. The final position of the particle as a function of time is

Four point objects of mass m are located at the corners of a square of side S as shown in the figure below. Determine the moment of inertia of this system about cd as shown in the figure.

The energy levels of a hypothetical one electron atom is given by En=−18.0n2eV where n = 1,2,3,..... Find the wavelength which will not be emitted when these atoms in the ground state are bombarded by electrons that have been accelerated through a potential difference of 16.2 V.