50278 + Interview Questions in Physics Page 62 InterviewSolution

3051.	In a sample of hydrogen atom in ground state, electrons make transition from ground state to a particular excited state where path length is five times de-broglie wavelength, electrons make back-transition to the ground state producing all possible photons. If photon having 2nd highest energy of this sample can be used to excite the electron in a particular excited state of Li2+ atom then find the final excited state of Li2+ atom
Answer» In a sample of hydrogen atom in ground state, electrons make transition from ground state to a particular excited state where path length is five times de-broglie wavelength, electrons make back-transition to the ground state producing all possible photons. If photon having 2nd highest energy of this sample can be used to excite the electron in a particular excited state of $L i^{2 +}$ atom then find the final excited state of $L i^{2 +}$ atom

Discussion

3052.	Nine resistors each of resistance R are connected in the circuit as shown in figure. The effective resistance between A and B is
Answer» Nine resistors each of resistance R are connected in the circuit as shown in figure. The effective resistance between A and B is

Discussion

3053.	Mass &volume of block measured by 22.42g and 4.7cm3.The maximum possible of error for density 1.0.6% 2.2.2% 3.2.8% 4.3.2%
Answer» Mass &volume of block measured by 22.42g and 4.7cm3.The maximum possible of error for density 1.0.6% 2.2.2% 3.2.8% 4.3.2%

Discussion

3054.	A book with many printing errors contains four different formulas for the displacement y of a particle undergoing a certain periodic motion : (a) y = a sin 2π t/T (b) y = a sin υt (c) y = (a/T) sin t/a (d) y = (a √2) (sin 2πt / T + cos 2πt / T ) (a = maximum displacement of the particle, υ = speed of the particle. T = time-period of motion). Rule out the wrong formulas on dimensional grounds.
Answer» A book with many printing errors contains four different formulas for the displacement y of a particle undergoing a certain periodic motion : (a) y = a sin 2π t/T (b) y = a sin υt (c) y = (a/T) sin t/a (d) y = (a √2) (sin 2πt / T + cos 2πt / T ) (a = maximum displacement of the particle, υ = speed of the particle. T = time-period of motion). Rule out the wrong formulas on dimensional grounds.

Discussion

3055.	The temp coefficient of resistence of tungsten is 4.5×10^{-3 }^° C^{-1 }and thats of germenium is -5×10^{-2 }^° C^{-1} . A tungsten of wire of resistence 100 ohm is connected in series with a germanium wire of resistence R. The value of R for which the resistence of combination does not change with temp is (1) 9 ohm (2) 1111 ohm (3) 0.9 ohm (4) 111.1 o
Answer» The temp coefficient of resistence of tungsten is 4.5×10^{-3 }^° C^{-1 }and thats of germenium is -5×10^{-2 }^° C^{-1} . A tungsten of wire of resistence 100 ohm is connected in series with a germanium wire of resistence R. The value of R for which the resistence of combination does not change with temp is (1) 9 ohm (2) 1111 ohm (3) 0.9 ohm (4) 111.1 o

Discussion

3056.	A student puts a small metallic sphere of work function 4.76 eV in a path of a beam of electromagnetic wave of uniform intensity.The radius of sphere is 1cm and it is left in the radiation for a long time. If the mass lost by sphere due to photoemission is 10Nme. Find the value of N.
Answer» A student puts a small metallic sphere of work function $4.76 eV$ in a path of a beam of electromagnetic wave of uniform intensity. The radius of sphere is $1 cm$ and it is left in the radiation for a long time. If the mass lost by sphere due to photoemission is $10^{N} m_{e}$ . Find the value of N.

Discussion

3057.	For the arrangement shown in figure, the effectivcapacitance between point P and Q is(1) 27 uF(2)1.3 FP(3) 6 uF(4) 4 uF
Answer» For the arrangement shown in figure, the effectivcapacitance between point P and Q is(1) 27 uF(2)1.3 FP(3) 6 uF(4) 4 uF

Discussion

3058.	Two vectors →A and →B are defined as →A=a^i and →B=a(cosωt^i+sinωt^j), where a is a constant and ω=π6rads−1. If ∣∣∣→A+→B∣∣∣=√3∣∣∣→A−→B∣∣∣ at time t=τ for the first time, then the value of τ, in seconds, is
Answer» Two vectors $\to A$ and $\to B$ are defined as $\to A = a^i$ and $\to B = a (cos ω t^i + sin ω t^j)$ , where $a$ is a constant and $ω = \frac{π}{6} r a d s^{- 1}$ . If $∣ ∣ ∣ \to A + \to B ∣ ∣ ∣ = \sqrt{3} ∣ ∣ ∣ \to A - \to B ∣ ∣ ∣$ at time $t = τ$ for the first time, then the value of $τ$ , in seconds, is

Discussion

3059.	Two short electric dipoles are placed as shown in figure.The energy of electric interaction between these dipoles will be :[Take k=14πε0]
Answer» Two short electric dipoles are placed as shown in figure. The energy of electric interaction between these dipoles will be : $[Take k = \frac{1}{4 π ε_{0}}]$

Discussion

3060.	Match List I with the List II and select the correct answer using the code given below the lists : List I List II(A)Area of a triangle with adjacent sides determined by vectors →a and →b is 1 sq. unit. Then the area (P)6(in sq. units) of the triangle with adjacent sides determined by (3→a+4→b) and (→a−3→b) is (B)Volume of parallelopiped determined by vectors →a,→b,→c is 14 cu. unit. Then the volume (in cu. units)(Q)9 of the parallelopiped determined by vectors 3(→a+→b),(→b+→c),4(→c+→a) is(C)Area of a parallelogram with adjacent sides determined by vectors →a and →b is 8 sq. units . Then the (R)13 area (in sq. units) of the parallelogram with adjacent sides determined by vectors (2→a+→b) and →b is (D)Volume of tetrahedron determined by vectors →a,→b and →c is 12 cu. unit. Then the volume (S)16 (in cu. units) of thetetrahedron determined by vectors 2(→a×→b),3(→b×→c) and (→c×→a) is Which of the following is a CORRECT combination?
Answer» Match $List I$ with the $List II$ and select the correct answer using the code given below the lists : $\begin{matrix} List I & List II (A) & Area of a triangle with adjacent sides determined by vectors \to a and \to b is 1 sq. unit . Then the area & (P) & 6 (in sq. units) of the triangle with adjacent sides determined by (3 \to a + 4 \to b) and (\to a - 3 \to b) is (B) & Volume of parallelopiped determined by vectors \to a, \to b, \to c is \frac{1}{4} cu. unit . Then the volume (in cu. units) & (Q) & 9 of the parallelopiped determined by vectors 3 (\to a + \to b), (\to b + \to c), 4 (\to c + \to a) is (C) & Area of a parallelogram with adjacent sides determined by vectors \to a and \to b is 8 sq. units . Then the & (R) & 13 area (in sq. units) of the parallelogram with adjacent sides determined by vectors (2 \to a + \to b) and \to b is (D) & Volume of tetrahedron determined by vectors \to a, \to b and \to c is \frac{1}{2} cu. unit . Then the volume & (S) & 16 (in cu. units) of thetetrahedron determined by vectors 2 (\to a \times \to b), 3 (\to b \times \to c) and (\to c \times \to a) is \end{matrix}$ Which of the following is a CORRECT combination?

Discussion

3061.	Monochromatic radiation emitted when electron onhydrogen atom jumps from first excited to the groundstate irradiates a photosensitive material. Thestopping potential is measured to be 3.57 V Thethreshold frequency of the material is
Answer» Monochromatic radiation emitted when electron onhydrogen atom jumps from first excited to the groundstate irradiates a photosensitive material. Thestopping potential is measured to be 3.57 V Thethreshold frequency of the material is

Discussion

3062.	A circular coil with its plane vertical is released from rest.It enters a region of a uniform magnetic field B at time t=t1 and leaves the region at time t=t2. The acceleration of the coil is
Answer» A circular coil with its plane vertical is released from rest.It enters a region of a uniform magnetic field B at time $t = t_{1}$ and leaves the region at time $t = t_{2}$ . The acceleration of the coil is

3062.

A circular coil with its plane vertical is released from rest.It enters a region of a uniform magnetic field B at time t=t1 and leaves the region at time t=t2. The acceleration of the coil is

Answer»

A circular coil with its plane vertical is released from rest.It enters a region of a uniform magnetic field B at time $t = t_{1}$ and leaves the region at time $t = t_{2}$ . The acceleration of the coil is

Discussion

3063.	2x is raised to power3 -3=10
Answer» 2x is raised to power3 -3=10

Discussion

3064.	A mechanical wave needs what all to propagate?
Answer» A mechanical wave needs what all to propagate?

Discussion

3065.	If ω1,ω2 and ω3 represent the work done in moving a particle from A to B along three different paths 1, 2, and 3 respectively in the presence of a gravitational field, then find the correct relation between ω1,ω2 and ω3.
Answer» If $ω_{1}, ω_{2}$ and $ω_{3}$ represent the work done in moving a particle from A to B along three different paths 1, 2, and 3 respectively in the presence of a gravitational field, then find the correct relation between $ω_{1}, ω_{2}$ and $ω_{3}$ .

Discussion

3066.	1) A mail bag is to be dropped into a post office from an aeroplane flying horizontally with a velocity of 270km/hr at a height of 176.4m above the ground.how far must the aeroplane be from the post office at the time of dropping the bag so that it directly falls into the post office?
Answer» 1) A mail bag is to be dropped into a post office from an aeroplane flying horizontally with a velocity of 270km/hr at a height of 176.4m above the ground.how far must the aeroplane be from the post office at the time of dropping the bag so that it directly falls into the post office?

Discussion

3067.	ntThe position of particle is given as y = 5 cos (10t + 15) m. The average velocity of particle from t = 0 to t = 3 sec {cos 15^° = 0.9659}n ntn
Answer» ntThe position of particle is given as y = 5 cos (10t + 15) m. The average velocity of particle from t = 0 to t = 3 sec {cos 15^° = 0.9659}n ntn

Discussion

3068.	A ball of massm strikes a rigid wall with speed v and getsreflected without any loss of speed as shown in figure. Thenwhat is the magnitude of the impulse imparted to the ball bythe wall?60^° 60^° 2 mvZeromvXmv2
Answer» A ball of massm strikes a rigid wall with speed v and getsreflected without any loss of speed as shown in figure. Thenwhat is the magnitude of the impulse imparted to the ball bythe wall?60^° 60^° 2 mvZeromvXmv2

Discussion

3069.	147.When an object is placed 20 cm from a concave mirror, a real image magnified three times is formed. Find a.) find the focal length of the mirror b.) where must the object be placed to give a virtual image three times the height of the object.
Answer» 147.When an object is placed 20 cm from a concave mirror, a real image magnified three times is formed. Find a.) find the focal length of the mirror b.) where must the object be placed to give a virtual image three times the height of the object.

Discussion

3070.	A block of mass 'm' is initially lying on a wedge of mass 'M' with an angle of inclination θ, as shown in the figure. Calculate the displacement of the wedge when the block reaches bottom of the wedge.
Answer» A block of mass 'm' is initially lying on a wedge of mass 'M' with an angle of inclination $θ$ , as shown in the figure. Calculate the displacement of the wedge when the block reaches bottom of the wedge.

Discussion

3071.	a particle is moving eastwards with a velocity of 5m/s.if in 10s the velocity changes by 5m/s northwards ,what is the average acceleration in this time?
Answer» a particle is moving eastwards with a velocity of 5m/s.if in 10s the velocity changes by 5m/s northwards ,what is the average acceleration in this time?

Discussion

3072.	A block at rest slides down smooth inclined plane which makes an angle 60degree with the vertical and it reaches the ground in t1 seconds . Another block is dropped vertically from same point and reaches the ground in t2 seconds. then the ratio of t1:t2 is
Answer» A block at rest slides down smooth inclined plane which makes an angle 60degree with the vertical and it reaches the ground in t1 seconds . Another block is dropped vertically from same point and reaches the ground in t2 seconds. then the ratio of t1:t2 is

Discussion

3073.	A body is thrown vertically upward with velocity u.The distance travelled by it in the 7th and 8thseconds are equal. The displacement in 8thseconds is equal to (take g = 10 m/s2)
Answer» A body is thrown vertically upward with velocity u.The distance travelled by it in the 7th and 8thseconds are equal. The displacement in 8thseconds is equal to (take g = 10 m/s2)

Discussion

3074.	A uniform electric field of magnitude E=100 N/C exists in the space in +x− direction. Calculate the flux of this field through a plane square of edge 10 cm placed in the y−z plane. Take the normal along the positive x− axis to be positive.
Answer» A uniform electric field of magnitude $E = 100 N/C$ exists in the space in $+ x -$ direction. Calculate the flux of this field through a plane square of edge $10 cm$ placed in the $y - z$ plane. Take the normal along the positive $x -$ axis to be positive.

Discussion

3075.	31. If length of seconds hands in a clock is 4 cm the angular velocity and linear velocity of the tip is ?
Answer» 31. If length of seconds hands in a clock is 4 cm the angular velocity and linear velocity of the tip is ?

Discussion

3076.	The potential energy of a particle of mass m at a distance r from a fixed point O is given by V(r)=kr2/2 , where k is a positive constant of appropriate dimensions. This particle is moving in a circular orbit of radius R about the point O. If v is the speed of the particle and L is the magnitude of its angular momentum about O, which of the following statements is (are) true?
Answer» The potential energy of a particle of mass $m$ at a distance $r$ from a fixed point $O$ is given by $V (r) = k r^{2} / 2$ , where $k$ is a positive constant of appropriate dimensions. This particle is moving in a circular orbit of radius $R$ about the point $O$ . If $v$ is the speed of the particle and $L$ is the magnitude of its angular momentum about $O$ , which of the following statements is (are) true?

Discussion

3077.	Let the angle between two nonzero vectors →A and →B be 120∘ and resultant be →C
Answer» Let the angle between two nonzero vectors $\to A$ and $\to B$ be $120^{\circ}$ and resultant be $\to C$

Discussion

3078.	A ball rolls without slipping. The radius of gyration of the ball about an axis passing through its center of mass is k. If radius of the ball is R, then the fraction of total energy associated with its rotational energy will be
Answer» A ball rolls without slipping. The radius of gyration of the ball about an axis passing through its center of mass is $k$ . If radius of the ball is $R$ , then the fraction of total energy associated with its rotational energy will be

Discussion

3079.	If average life is τ and half-life is t12 then
Answer» If average life is τ and half-life is $t_{\frac{1}{2}}$ then

Discussion

3080.	A body is dropped from a height . It covers first half of height in 10 seconds . The time of fall of body is?
Answer» A body is dropped from a height . It covers first half of height in 10 seconds . The time of fall of body is?

Discussion

3081.	Four massless springs whose force constants are 2k,2k,k and 2k, respectively, are attached to a mass M kept on a frictionless horizontal plane (as shown in figure). If the other ends of the springs are fixed and the mass M is displaced , then the frequency of oscillation of the system is
Answer» Four massless springs whose force constants are $2 k, 2 k, k$ and $2 k$ , respectively, are attached to a mass $M$ kept on a frictionless horizontal plane (as shown in figure). If the other ends of the springs are fixed and the mass $M$ is displaced , then the frequency of oscillation of the system is

Discussion

3082.	consider a wire of circular cross section of radius R having current density J=J_or then find current in the wire
Answer» consider a wire of circular cross section of radius R having current density J=J_or then find current in the wire

Discussion

3083.	Two identical copper spheres are separated by 1m in vaccum. How many electrons have to be removed from one sphere and added to the other so that they now attract each other with a force of0.9 N
Answer» Two identical copper spheres are separated by 1m in vaccum. How many electrons have to be removed from one sphere and added to the other so that they now attract each other with a force of0.9 N

Discussion

3084.	A particle of unit mass undergoes ane-dimensional motion such that its velocity varies according to {v(x)=β x^{2n , where β and n are constants and x is the position of the particle. The acceleration of the particle { as a function of x , is given by
Answer» A particle of unit mass undergoes ane-dimensional motion such that its velocity varies according to {v(x)=β x^{2n , where β and n are constants and x is the position of the particle. The acceleration of the particle { as a function of x , is given by

Discussion

3085.	The correct variation of pressure with depth (x) is: [Assume the free surface to be the reference and conditions to be ideal]
Answer» The correct variation of pressure with depth $(x)$ is: [Assume the free surface to be the reference and conditions to be ideal]

Discussion

3086.	A boy is standing inside a train moving with a constant velocity of magnitude 10 m/s. He throws a ball vertically up with a speed of 5 m/s relative to the train. Find the radius of curvature of the path of the ball just at the time of projection. (Take g=10m/s2)
Answer» A boy is standing inside a train moving with a constant velocity of magnitude $10 m / s$ . He throws a ball vertically up with a speed of $5 m / s$ relative to the train. Find the radius of curvature of the path of the ball just at the time of projection. (Take $g = 10 m / s^{2}$ )

Discussion

3087.	The refractive index of diamond with respect to glass is 1.6. If the absolute refractive index of glass is 1.5, calculate the absolute refractive index of diamond.
Answer» The refractive index of diamond with respect to glass is 1.6. If the absolute refractive index of glass is 1.5, calculate the absolute refractive index of diamond.

Discussion

3088.	What is a leaving group? And what does Poor Base and Better Base exactly mean. And how does this depend on the quality of the leaving group?
Answer» What is a leaving group? And what does Poor Base and Better Base exactly mean. And how does this depend on the quality of the leaving group?

Discussion

3089.	Two lenses in contact form an achromatic lens, Their focal lengths are in the ratio 2:3. Their disperive powers must be in the ratio of
Answer» Two lenses in contact form an achromatic lens, Their focal lengths are in the ratio $2 : 3$ . Their disperive powers must be in the ratio of

Discussion

3090.	A body is having a charge of 10 C. When it comes in contact with an charged body then it loses-1.6C of charge. Find the number of electrons lost.
Answer» A body is having a charge of 10 C. When it comes in contact with an charged body then it loses-1.6C of charge. Find the number of electrons lost.

Discussion

3091.	Why we have to take halfof the length of heavy object while finding its elongation.Explain in detail
Answer» Why we have to take halfof the length of heavy object while finding its elongation.Explain in detail

Discussion

3092.	A beam of rectangular cross-section is subjected to a vertical shear force V. The shear force carried by upper one-fourth of the cross-section is __________V.0.156
Answer» A beam of rectangular cross-section is subjected to a vertical shear force V. The shear force carried by upper one-fourth of the cross-section is __________V. 0.156

Discussion

3093.	In the given figure, the position-time graph of a particle of mass 0.1 kg is shown. The impulse at t=2 sec is
Answer» In the given figure, the position-time graph of a particle of mass $0.1 kg$ is shown. The impulse at $t = 2 sec$ is

Discussion

3094.	Two uniform rods of equal lengths but different masses are rigidly joined to form an L- shaped body, which is then pivoted about O as shown in the figure. Find the net torque about point O. Given M=m√3
Answer» Two uniform rods of equal lengths but different masses are rigidly joined to form an $L$ - shaped body, which is then pivoted about $O$ as shown in the figure. Find the net torque about point $O$ . Given $M = m \sqrt{3}$

Discussion

3095.	if the electric field intensity in a fair weather atmosphere is 1000 v/m ,then the total charge on the earth surface is (radius of the earth is 6400km).
Answer» if the electric field intensity in a fair weather atmosphere is 1000 v/m ,then the total charge on the earth surface is (radius of the earth is 6400km).

Discussion

3096.	A charge Q is distributed over two concentric hollow spheres of radii r and R (>r) such that the surface densities are equal. The potential at the centre is
Answer» A charge Q is distributed over two concentric hollow spheres of radii r and R (>r) such that the surface densities are equal. The potential at the centre is

Discussion

3097.	the period of the function f(x)=sinx+tanx/2
Answer» the period of the function f(x)=sinx+tanx/2

Discussion

3098.	Explain friction is a necessary evil
Answer» Explain friction is a necessary evil

Discussion

3099.	Two concentric coils each of radius equal to 2 π cm are placed right angles to each other. If 3A and 4A are the currents flowing through the two coils respectively. The magnetic induction (in Wb m-2) at the center of the coils will be
Answer» Two concentric coils each of radius equal to 2 $π$ cm are placed right angles to each other. If 3A and 4A are the currents flowing through the two coils respectively. The magnetic induction (in Wb m-2) at the center of the coils will be

Discussion

3100.	A bat is emitting the ultrasonic sound of frequency 100 kHz in air. What will be the wavelength of sound heard by a person inside a lake over which bat is flying?[speed of sound in air =340 ms−1 and speed of sound in water =1500 ms−1]
Answer» A bat is emitting the ultrasonic sound of frequency $100 kHz$ in air. What will be the wavelength of sound heard by a person inside a lake over which bat is flying? [speed of sound in air $= 340 {ms}^{- 1}$ and speed of sound in water $= 1500 {ms}^{- 1}$ ]

Discussion

Explore topic-wise InterviewSolutions in .

Nine resistors each of resistance R are connected in the circuit as shown in figure. The effective resistance between A and B is

Mass &volume of block measured by 22.42g and 4.7cm3.The maximum possible of error for density 1.0.6% 2.2.2% 3.2.8% 4.3.2%

A student puts a small metallic sphere of work function 4.76 eV in a path of a beam of electromagnetic wave of uniform intensity.The radius of sphere is 1cm and it is left in the radiation for a long time. If the mass lost by sphere due to photoemission is 10Nme. Find the value of N.

For the arrangement shown in figure, the effectivcapacitance between point P and Q is(1) 27 uF(2)1.3 FP(3) 6 uF(4) 4 uF

Two vectors →A and →B are defined as →A=a^i and →B=a(cosωt^i+sinωt^j), where a is a constant and ω=π6rads−1. If ∣∣∣→A+→B∣∣∣=√3∣∣∣→A−→B∣∣∣ at time t=τ for the first time, then the value of τ, in seconds, is

Two short electric dipoles are placed as shown in figure.The energy of electric interaction between these dipoles will be :[Take k=14πε0]

Monochromatic radiation emitted when electron onhydrogen atom jumps from first excited to the groundstate irradiates a photosensitive material. Thestopping potential is measured to be 3.57 V Thethreshold frequency of the material is

A circular coil with its plane vertical is released from rest.It enters a region of a uniform magnetic field B at time t=t1 and leaves the region at time t=t2. The acceleration of the coil is

2x is raised to power3 -3=10

A mechanical wave needs what all to propagate?

If ω1,ω2 and ω3 represent the work done in moving a particle from A to B along three different paths 1, 2, and 3 respectively in the presence of a gravitational field, then find the correct relation between ω1,ω2 and ω3.

1) A mail bag is to be dropped into a post office from an aeroplane flying horizontally with a velocity of 270km/hr at a height of 176.4m above the ground.how far must the aeroplane be from the post office at the time of dropping the bag so that it directly falls into the post office?

ntThe position of particle is given as y = 5 cos (10t + 15) m. The average velocity of particle from t = 0 to t = 3 sec {cos 15^° = 0.9659}n ntn

A ball of massm strikes a rigid wall with speed v and getsreflected without any loss of speed as shown in figure. Thenwhat is the magnitude of the impulse imparted to the ball bythe wall?60^° 60^° 2 mvZeromvXmv2

147.When an object is placed 20 cm from a concave mirror, a real image magnified three times is formed. Find a.) find the focal length of the mirror b.) where must the object be placed to give a virtual image three times the height of the object.

A block of mass 'm' is initially lying on a wedge of mass 'M' with an angle of inclination θ, as shown in the figure. Calculate the displacement of the wedge when the block reaches bottom of the wedge.

a particle is moving eastwards with a velocity of 5m/s.if in 10s the velocity changes by 5m/s northwards ,what is the average acceleration in this time?

A block at rest slides down smooth inclined plane which makes an angle 60degree with the vertical and it reaches the ground in t1 seconds . Another block is dropped vertically from same point and reaches the ground in t2 seconds. then the ratio of t1:t2 is

A body is thrown vertically upward with velocity u.The distance travelled by it in the 7th and 8thseconds are equal. The displacement in 8thseconds is equal to (take g = 10 m/s2)

A uniform electric field of magnitude E=100 N/C exists in the space in +x− direction. Calculate the flux of this field through a plane square of edge 10 cm placed in the y−z plane. Take the normal along the positive x− axis to be positive.

31. If length of seconds hands in a clock is 4 cm the angular velocity and linear velocity of the tip is ?

Let the angle between two nonzero vectors →A and →B be 120∘ and resultant be →C

A ball rolls without slipping. The radius of gyration of the ball about an axis passing through its center of mass is k. If radius of the ball is R, then the fraction of total energy associated with its rotational energy will be

If average life is τ and half-life is t12 then

A body is dropped from a height . It covers first half of height in 10 seconds . The time of fall of body is?

Four massless springs whose force constants are 2k,2k,k and 2k, respectively, are attached to a mass M kept on a frictionless horizontal plane (as shown in figure). If the other ends of the springs are fixed and the mass M is displaced , then the frequency of oscillation of the system is

consider a wire of circular cross section of radius R having current density J=J_or then find current in the wire

Two identical copper spheres are separated by 1m in vaccum. How many electrons have to be removed from one sphere and added to the other so that they now attract each other with a force of0.9 N

A particle of unit mass undergoes ane-dimensional motion such that its velocity varies according to {v(x)=β x^{2n , where β and n are constants and x is the position of the particle. The acceleration of the particle { as a function of x , is given by

The correct variation of pressure with depth (x) is: [Assume the free surface to be the reference and conditions to be ideal]

A boy is standing inside a train moving with a constant velocity of magnitude 10 m/s. He throws a ball vertically up with a speed of 5 m/s relative to the train. Find the radius of curvature of the path of the ball just at the time of projection. (Take g=10m/s2)

The refractive index of diamond with respect to glass is 1.6. If the absolute refractive index of glass is 1.5, calculate the absolute refractive index of diamond.

What is a leaving group? And what does Poor Base and Better Base exactly mean. And how does this depend on the quality of the leaving group?

Two lenses in contact form an achromatic lens, Their focal lengths are in the ratio 2:3. Their disperive powers must be in the ratio of

A body is having a charge of 10 C. When it comes in contact with an charged body then it loses-1.6C of charge. Find the number of electrons lost.

Why we have to take halfof the length of heavy object while finding its elongation.Explain in detail

A beam of rectangular cross-section is subjected to a vertical shear force V. The shear force carried by upper one-fourth of the cross-section is __________V.0.156

In the given figure, the position-time graph of a particle of mass 0.1 kg is shown. The impulse at t=2 sec is

Two uniform rods of equal lengths but different masses are rigidly joined to form an L- shaped body, which is then pivoted about O as shown in the figure. Find the net torque about point O. Given M=m√3

if the electric field intensity in a fair weather atmosphere is 1000 v/m ,then the total charge on the earth surface is (radius of the earth is 6400km).

A charge Q is distributed over two concentric hollow spheres of radii r and R (>r) such that the surface densities are equal. The potential at the centre is

the period of the function f(x)=sinx+tanx/2

Explain friction is a necessary evil

Two concentric coils each of radius equal to 2 π cm are placed right angles to each other. If 3A and 4A are the currents flowing through the two coils respectively. The magnetic induction (in Wb m-2) at the center of the coils will be

A bat is emitting the ultrasonic sound of frequency 100 kHz in air. What will be the wavelength of sound heard by a person inside a lake over which bat is flying?[speed of sound in air =340 ms−1 and speed of sound in water =1500 ms−1]