50278 + Interview Questions in Physics Page 157 InterviewSolution

7801.	The electric field at distance 10 cm from the centre of a uniformly charged non-conducting sphere of radius 5 cm is E. Then at a distance 2.5 cm from the centre, electric field will beOptions: 1)E 2)2E 3)4E 4)Zero
Answer» The electric field at distance 10 cm from the centre of a uniformly charged non-conducting sphere of radius 5 cm is E. Then at a distance 2.5 cm from the centre, electric field will be Options: 1)E 2)2E 3)4E 4)Zero

Discussion

7802.	Two bodies of masses m1 and m2 are connected by a light, inextensible string, which passes over a frictionless pulley. If the pulley is moving upward with uniform acceleration g, then the tension in the string is
Answer» Two bodies of masses m₁ and m₂ are connected by a light, inextensible string, which passes over a frictionless pulley. If the pulley is moving upward with uniform acceleration g, then the tension in the string is

Discussion

7803.	A rod closing the circuit shown in the figure moves along a V- shaped wire of a constant speed of 5 m/s under the action of force P. The circuit is in a uniform magnetic field perpendicular to the plane. Calculate the force P acting on the rod, if the rate of heat generation in the circuit is 15 J/s.
Answer» A rod closing the circuit shown in the figure moves along a $V-$ shaped wire of a constant speed of $5 m/s$ under the action of force $P$ . The circuit is in a uniform magnetic field perpendicular to the plane. Calculate the force $P$ acting on the rod, if the rate of heat generation in the circuit is $15 J/s$ .

Discussion

7804.	The angular width of the central maximum in a single slit diffraction pattern is 60∘. The width of the slit is 1 μm. The slit is illuminated by monochromatic plane waves. If another slit of the same width is made near it, Young's Fringes can be observed on a screen placed at a distance 50 cm from the slits. If the observed fringe width is 1 cm. What is slit separation distance? (i.e. distance between the centre of each slit)
Answer» The angular width of the central maximum in a single slit diffraction pattern is $60^{\circ}$ . The width of the slit is $1 μ m$ . The slit is illuminated by monochromatic plane waves. If another slit of the same width is made near it, Young's Fringes can be observed on a screen placed at a distance $50 cm$ from the slits. If the observed fringe width is $1 cm$ . What is slit separation distance? $(i.e. distance between the centre of each slit)$

Discussion

7805.	Two parallel glass plates are dipped partly in the liquid of density d keeping them vertical. If the distance between the plates is x, surface tension of liquid is T and angle of contact is θ, then the rise of liquid between the plates due to capillarity will be
Answer» Two parallel glass plates are dipped partly in the liquid of density $d$ keeping them vertical. If the distance between the plates is $x$ , surface tension of liquid is $T$ and angle of contact is $θ$ , then the rise of liquid between the plates due to capillarity will be

Discussion

7806.	In Thomson's experiment, a magnetic field of induction 10−2 Wb m−2 is used. For an undeflected beam of cathode rays, a potential difference of 500 V is applied between the plates, which are 0.5 cm apart. Then the velocity of the cathode ray beam is (in ms−1).
Answer» In Thomson's experiment, a magnetic field of induction $10^{- 2} {Wb m}^{- 2}$ is used. For an undeflected beam of cathode rays, a potential difference of $500 V$ is applied between the plates, which are $0.5 cm$ apart. Then the velocity of the cathode ray beam is (in ${ms}^{- 1}$ ).

Discussion

7807.	A bullet with mass 200 gm and velocity vb m/s hits a ballistic pendulum bob of mass 800 gm and rises along with pendulum to a height h=0.2 m. Determine the value of vb. Take g=10 m/s2.
Answer» A bullet with mass $200 gm$ and velocity $v_{b} m/s$ hits a ballistic pendulum bob of mass $800 gm$ and rises along with pendulum to a height $h = 0.2 m$ . Determine the value of $v_{b} .$ Take $g = 10 {m/s}^{2}$ .

Discussion

7808.	A rod of mass M and length L that is hinged about its end point is released from rest from horizontal position in a vertical plane as shown in figure. Hinge reaction when rod becomes vertical is pq Mg then p+q is (where p & q are coprime)
Answer» A rod of mass M and length L that is hinged about its end point is released from rest from horizontal position in a vertical plane as shown in figure. Hinge reaction when rod becomes vertical is $\frac{p}{q}$ Mg then p+q is (where p & q are coprime)

Discussion

7809.	A concave mirror of focal length 40cm forms a real image of an object of size 3 times size of object. Find out position of both object and image.
Answer» A concave mirror of focal length 40cm forms a real image of an object of size 3 times size of object. Find out position of both object and image.

Discussion

7810.	In the figure shown the wires AB and PQ carry constant currents I1 and I2 respectively. PQ is of uniformly distributed mass m and length l. AB and PQ are both horizontal and kept in the same vertical plane. The PQ is in equilibrium at height h, If the wire PQ is displaced vertically by small distance, then its time period of oscillation in terms of h and g
Answer» In the figure shown the wires $AB$ and $PQ$ carry constant currents $I_{1}$ and $I_{2}$ respectively. $PQ$ is of uniformly distributed mass $m$ and length $l$ . $AB$ and $PQ$ are both horizontal and kept in the same vertical plane. The $PQ$ is in equilibrium at height $h$ , If the wire $PQ$ is displaced vertically by small distance, then its time period of oscillation in terms of $h$ and $g$

Discussion

7811.	43. The de Broglie wavelength of a particle with mass1 g and velocity 100 m/s is(1) 6.63 x10^{-35}m(2) 6.63 x 10^{-34}m(3) 6.63x 10^{-33}m(4)6.65 x 10^{-35} m
Answer» 43. The de Broglie wavelength of a particle with mass1 g and velocity 100 m/s is(1) 6.63 x10^{-35}m(2) 6.63 x 10^{-34}m(3) 6.63x 10^{-33}m(4)6.65 x 10^{-35} m

Discussion

7812.	When using high voltage to carry current over a large distance, wouldn't the heat loss be high too due to the equation P=V^2/R. Just like it is high for high values of I?
Answer» When using high voltage to carry current over a large distance, wouldn't the heat loss be high too due to the equation P=V^2/R. Just like it is high for high values of I?

Discussion

7813.	A block of weight W is kept on an inclined surface whose angle of inclination is θ with horizontal. The component of weight along the incline is
Answer» A block of weight $W$ is kept on an inclined surface whose angle of inclination is $θ$ with horizontal. The component of weight along the incline is

Discussion

7814.	118. In the given figure current carrying conductor will
Answer» 118. In the given figure current carrying conductor will

Discussion

7815.	Consider a ring of mass m and radius r. Maximum gravitational intensity on the axis of the ring has the valu
Answer» Consider a ring of mass m and radius r. Maximum gravitational intensity on the axis of the ring has the valu

Discussion

7816.	36. Three infinitely long line charges having linear charge density A,2A,3Aare placed along x axis y axis and Z Axis respectively the work done by the electric field in moving a unit positive charge from (2,2,2) to (2,2,0) will be----
Answer» 36. Three infinitely long line charges having linear charge density A,2A,3Aare placed along x axis y axis and Z Axis respectively the work done by the electric field in moving a unit positive charge from (2,2,2) to (2,2,0) will be----

Discussion

7817.	what is the correct relation for a solution 1) ψ w = ψ s + ψ p 2) ψ w = ψ s 3)ψ p =ψ s 4) no
Answer» what is the correct relation for a solution 1) ψ w = ψ s + ψ p 2) ψ w = ψ s 3)ψ p =ψ s 4) no

Discussion

7818.	In a double-slit experiment the angular width of a fringe is found to be 0.2° on a screen placed 1 m away. The wavelength of light used is 600 nm. What will be the angular width of the fringe if the entire experimental apparatus is immersed in water? Take refractive index of water to be 4/3.
Answer» In a double-slit experiment the angular width of a fringe is found to be 0.2° on a screen placed 1 m away. The wavelength of light used is 600 nm. What will be the angular width of the fringe if the entire experimental apparatus is immersed in water? Take refractive index of water to be 4/3.

Discussion

7819.	consider a parallel plate capacitor with plate area A . A positive charge +Q is given to one plate and a negative charge -2Q is given to other plate . what is the force of inteaction between them
Answer» consider a parallel plate capacitor with plate area A . A positive charge +Q is given to one plate and a negative charge -2Q is given to other plate . what is the force of inteaction between them

Discussion

7820.	In the circuit shown in the figure, the input voltage Vi is 20 V, VBE=0 V and VCE=0 V. The value of IB is given by
Answer» In the circuit shown in the figure, the input voltage $V_{i}$ is $20 V$ , $V_{B E} = 0 V$ and $V_{C E} = 0 V$ . The value of $I_{B}$ is given by

Discussion

7821.	Is it necessary that a measurement which is accurate must be precise or a measurement which is precise must be accurate?
Answer» Is it necessary that a measurement which is accurate must be precise or a measurement which is precise must be accurate?

Discussion

7822.	{ The ratio of displacement in }n second and in the }}{n^ th } second for a particle moving in a straight line }} under constant acceleration starting from rest is
Answer» { The ratio of displacement in }n second and in the }}{n^ th } second for a particle moving in a straight line }} under constant acceleration starting from rest is

Discussion

7823.	The vector →P=a^i+a^j+3^k and →Q=a^i−2^j−^k are perpendicular to each other. The positive value of a is
Answer» The vector $\to P = a^i + a^j + 3^k and \to Q = a^i - 2^j -^k$ are perpendicular to each other. The positive value of $a$ is

Discussion

7824.	Two spherical bodies of mass m, 5m and radius R, 2R respectively are released in free space with an initial separation of 12R between their centres. If they attract each other due to gravitational force alone, then the distance covered by the smaller body just before the collision is
Answer» Two spherical bodies of mass $m$ , $5 m$ and radius $R$ , $2 R$ respectively are released in free space with an initial separation of $12 R$ between their centres. If they attract each other due to gravitational force alone, then the distance covered by the smaller body just before the collision is

Discussion

7825.	What are solid angles?
Answer» What are solid angles?

Discussion

7826.	A vertical rod of length l is now moving with a constant velocity v towards east. the vertical component of Earth's magnetic field is B and angle of dip is theta . The induced EMF in the rod is : Blv sin theta Blv cos theta Blv cot theta Blv tan theta
Answer» A vertical rod of length l is now moving with a constant velocity v towards east. the vertical component of Earth's magnetic field is B and angle of dip is theta . The induced EMF in the rod is : Blv sin theta Blv cos theta Blv cot theta Blv tan theta

Discussion

7827.	An object looks red when seen through a piece of red glass. What is the actual colour of the object? (1)Red only (2)White only (3)Red or green (4)Black
Answer» An object looks red when seen through a piece of red glass. What is the actual colour of the object? (1)Red only (2)White only (3)Red or green (4)Black

Discussion

7828.	19) a+b+c=0 find ( (b-c )/ a + (c-a)/ b + (a-b)/ c )( c /(a-b ) + a /(b-c) + b/( c-a )
Answer» 19) a+b+c=0 find ( (b-c )/ a + (c-a)/ b + (a-b)/ c )( c /(a-b ) + a /(b-c) + b/( c-a )

Discussion

7829.	A uniform rope of length l lies on a table. If the coefficient of friction is μ, then the maximum length l1 of the hanging part of the rope which can overhang from the edge of the table without sliding down is
Answer» A uniform rope of length $l$ lies on a table. If the coefficient of friction is $μ$ , then the maximum length $l_{1}$ of the hanging part of the rope which can overhang from the edge of the table without sliding down is

Discussion

7830.	If we place a bar magnet in the magnetic meridian with its north pole towards geographical North, the neutral point will be 1.on the axial of the magnet 2.on the equatorial line line of magnet 3.at 45 with the axial line 4. At 45 with equatorial line
Answer» If we place a bar magnet in the magnetic meridian with its north pole towards geographical North, the neutral point will be 1.on the axial of the magnet 2.on the equatorial line line of magnet 3.at 45 with the axial line 4. At 45 with equatorial line

7830.

If we place a bar magnet in the magnetic meridian with its north pole towards geographical North, the neutral point will be 1.on the axial of the magnet 2.on the equatorial line line of magnet 3.at 45 with the axial line 4. At 45 with equatorial line

Answer»

If we place a bar magnet in the magnetic meridian with its north pole towards geographical North, the neutral point will be

1.on the axial of the magnet

2.on the equatorial line line of magnet

3.at 45 with the axial line

4. At 45 with equatorial line

Discussion

7831.	A body of m is moving in a straight line at a constant speed v. Its kinetic energy is k and the magnitude of its momentum is p. Which of the following relations is/are correct?
Answer» A body of m is moving in a straight line at a constant speed v. Its kinetic energy is k and the magnitude of its momentum is p. Which of the following relations is/are correct?

Discussion

7832.	A force acts on a 30 g particle in such a way that the position of the particle as a function of time is given by x=3t−4t2+t3, where x is in meters and t is in seconds. The work done during the first 4 seconds is
Answer» A force acts on a $30 g$ particle in such a way that the position of the particle as a function of time is given by $x = 3 t - 4 t^{2} + t^{3}$ , where $x$ is in meters and $t$ is in seconds. The work done during the first $4$ seconds is

Discussion

7833.	Below Figure shows a man of mass 60 kg standing on a light weighing machine kept in a box of mass 30 kg. The box is hanging from a pulley fixed to the ceiling through a light rope, the other end of which is held by the man himself. If the man manages to keep the box at rest, what is the weight shown by the machine? What force should he exert on the rope to get his correct weight on the machine?
Answer» Below Figure shows a man of mass 60 kg standing on a light weighing machine kept in a box of mass 30 kg. The box is hanging from a pulley fixed to the ceiling through a light rope, the other end of which is held by the man himself. If the man manages to keep the box at rest, what is the weight shown by the machine? What force should he exert on the rope to get his correct weight on the machine?

7833.

Below Figure shows a man of mass 60 kg standing on a light weighing machine kept in a box of mass 30 kg. The box is hanging from a pulley fixed to the ceiling through a light rope, the other end of which is held by the man himself. If the man manages to keep the box at rest, what is the weight shown by the machine? What force should he exert on the rope to get his correct weight on the machine?

Answer»

Below Figure shows a man of mass 60 kg standing on a light weighing machine kept in a box of mass 30 kg. The box is hanging from a pulley fixed to the ceiling through a light rope, the other end of which is held by the man himself. If the man manages to keep the box at rest, what is the weight shown by the machine? What force should he exert on the rope to get his correct weight on the machine?

Discussion

7834.	A laminar body is uniformly rotating about an axis fixed in an inertial frame of reference. Let →A be vector along the axis of rotation and →B be the unit vector along the resultant force on a particle P of the body away from the axis. The value of →A.→B is:
Answer» A laminar body is uniformly rotating about an axis fixed in an inertial frame of reference. Let $\to A$ be vector along the axis of rotation and $\to B$ be the unit vector along the resultant force on a particle P of the body away from the axis. The value of $\to A . \to B$ is:

Discussion

7835.	A partical is moving in the xy-plane has velocity components dx/dt =2t and dy/dt=4. If the partical start from the origin at t=0 , magnitude of its displacement at t=2s is
Answer» A partical is moving in the xy-plane has velocity components dx/dt =2t and dy/dt=4. If the partical start from the origin at t=0 , magnitude of its displacement at t=2s is

Discussion

7836.	The degree of static indeterminacy of truss given below is.3
Answer» The degree of static indeterminacy of truss given below is. 3

Discussion

7837.	There is a horizontal film of soap solution. On it, a thread is placed in the form of a loop. The film is pierced inside the loop and the thread becomes a circular loop of radius R. if the surface tension of the loop be T, then what will be the tension in the thread?
Answer» There is a horizontal film of soap solution. On it, a thread is placed in the form of a loop. The film is pierced inside the loop and the thread becomes a circular loop of radius R. if the surface tension of the loop be T, then what will be the tension in the thread?

Discussion

7838.	A projectile is fired horizontally from an inclined plane of inclination 45 degree with horizontal with speed 50 m/s g=10 then range along incline is
Answer» A projectile is fired horizontally from an inclined plane of inclination 45 degree with horizontal with speed 50 m/s g=10 then range along incline is

Discussion

7839.	The maximum height of an oblique projectile is 8 m. The horizontal range is 24 m. The horizontal component of the velocity of projection is
Answer» The maximum height of an oblique projectile is $8 m$ . The horizontal range is $24 m$ . The horizontal component of the velocity of projection is

Discussion

7840.	A galvanometer of resistance 95 Ω shunted by a resistance of 5 Ω gives a deflection of 50 divisions when joined in series with a resistance of 20 kΩ and a 2 V accumulator. What is the current sensitivity of the galvanometer in div/μA?
Answer» A galvanometer of resistance $95 Ω$ shunted by a resistance of $5 Ω$ gives a deflection of $50$ divisions when joined in series with a resistance of $20 k Ω$ and a $2 V$ accumulator. What is the current sensitivity of the galvanometer in $div / μ A$ ?

Discussion

7841.	As shown in fig., two identical capacitors are connected to a battery of V volts in parallel. When capacitors are fully charged their energy is U1. If the key K is opened and a material of dielectric constant εr=2 is inserted in each capacitors their stored energy is now U2. Then, U1U2 will be
Answer» As shown in fig., two identical capacitors are connected to a battery of $V volts$ in parallel. When capacitors are fully charged their energy is $U_{1}$ . If the key $K$ is opened and a material of dielectric constant $ε_{r} = 2$ is inserted in each capacitors their stored energy is now $U_{2} .$ Then, $\frac{U_{1}}{U_{2}}$ will be

Discussion

7842.	A long metallic rod along the E-W direction falls under gravity.potential difference between its two ends
Answer» A long metallic rod along the E-W direction falls under gravity.potential difference between its two ends

Discussion

7843.	Given that v is the speed, r is the radius and g is the acceleration due to gravity. Which of the following is dimensionless ?
Answer» Given that v is the speed, r is the radius and g is the acceleration due to gravity. Which of the following is dimensionless ?

Discussion

7844.	Q15/15 A perfectly reflecting solid hemisphere of radius }R is placed } in the path of a parallel beam of light of large aperature. If the beam } carries an intensity }, the force exerted by the beam on the } hemisphere is
Answer» Q15/15 A perfectly reflecting solid hemisphere of radius }R is placed } in the path of a parallel beam of light of large aperature. If the beam } carries an intensity }, the force exerted by the beam on the } hemisphere is

Discussion

7845.	The magnitude of the force (in N) acting on a body varies with time t (in μs) as shown. AB,BC and CD are straight line segments. The magnitude of the total impule of the force on the body from t=4 μs to t=16 μs is
Answer» The magnitude of the force (in $N$ ) acting on a body varies with time $t$ (in $μ s$ ) as shown. $A B, B C$ and $C D$ are straight line segments. The magnitude of the total impule of the force on the body from $t = 4 μ s$ to $t = 16 μ s$ is

Discussion

7846.	When a sinusoidal message signal is applied to the X-plates of a CRO and the corresponding amplitude modulated (AM) signal is applied to the y-plates, the X-Y plot displayed on the screen of the CRO is as shown in the figure below.The modulation index of the AM signal is equal to _____.1.67
Answer» When a sinusoidal message signal is applied to the X-plates of a CRO and the corresponding amplitude modulated (AM) signal is applied to the y-plates, the X-Y plot displayed on the screen of the CRO is as shown in the figure below. The modulation index of the AM signal is equal to _____. 1.67

Discussion

7847.	The diameter of a cylinder is measured using a Vernier calipers with no zero error. It is found that the zero of the Vernier scale lies between 5.10 cm and 5.15 cm of the main scale. The Vernier scale has 50 divisions equivalent to 2.45 cm. The 24th division of the Vernier scale excatly coincides with one of the main scale divisions. The diameter of the cylinder is :-
Answer» The diameter of a cylinder is measured using a Vernier calipers with no zero error. It is found that the zero of the Vernier scale lies between $5.10 cm$ and $5.15 cm$ of the main scale. The Vernier scale has $50$ divisions equivalent to $2.45 cm$ . The $24^{t h}$ division of the Vernier scale excatly coincides with one of the main scale divisions. The diameter of the cylinder is :-

Discussion

7848.	Unpolarized light of intensity 32 Wm−2 passes through three polarizers arranged in a way, such that the transmission axis of the last polarizer is crossed with that of the first. If the intensity of emerging light is 3 Wm−2, what is the angle between the axis of first two polarizers?
Answer» Unpolarized light of intensity $32 {Wm}^{- 2}$ passes through three polarizers arranged in a way, such that the transmission axis of the last polarizer is crossed with that of the first. If the intensity of emerging light is $3 {Wm}^{- 2}$ , what is the angle between the axis of first two polarizers?

Discussion

7849.	Two Carnot engines A and B are operated in succession. The first one, A receives heat from a source at T1=800 K and rejects to a sink at T2 K. The second engine B receives heat rejected by the first engine and rejects to another sink at T3=300 K. Find the value of T2 if (i) the work outputs of the two engines are equal. (ii) the efficiencies of the two engines are equal.
Answer» Two Carnot engines $A$ and $B$ are operated in succession. The first one, $A$ receives heat from a source at $T_{1} = 800 K$ and rejects to a sink at $T_{2} K$ . The second engine $B$ receives heat rejected by the first engine and rejects to another sink at $T_{3} = 300 K$ . Find the value of $T_{2}$ if (i) the work outputs of the two engines are equal. (ii) the efficiencies of the two engines are equal.

Discussion

7850.	For a mixture of two volatile, completely miscible liquids A and B, with P0A=500 torr and P0B=800 torr. What is the composition of last of liquid remaining in equilibrium with vapour?Provided the initial ideal solution has a composition of xA=0.6 and xB=0.4, where xA and xB are the mole fraction of A and B respectively
Answer» For a mixture of two volatile, completely miscible liquids A and B, with $P_{A}^{0} = 500$ torr and $P_{B}^{0} = 800$ torr. What is the composition of last of liquid remaining in equilibrium with vapour? Provided the initial ideal solution has a composition of $x_{A} = 0.6$ and $x_{B} = 0.4$ , where $x_{A} and x_{B}$ are the mole fraction of $A$ and $B$ respectively

Discussion

Explore topic-wise InterviewSolutions in .

The electric field at distance 10 cm from the centre of a uniformly charged non-conducting sphere of radius 5 cm is E. Then at a distance 2.5 cm from the centre, electric field will beOptions: 1)E 2)2E 3)4E 4)Zero

Two bodies of masses m1 and m2 are connected by a light, inextensible string, which passes over a frictionless pulley. If the pulley is moving upward with uniform acceleration g, then the tension in the string is

Two parallel glass plates are dipped partly in the liquid of density d keeping them vertical. If the distance between the plates is x, surface tension of liquid is T and angle of contact is θ, then the rise of liquid between the plates due to capillarity will be

In Thomson's experiment, a magnetic field of induction 10−2 Wb m−2 is used. For an undeflected beam of cathode rays, a potential difference of 500 V is applied between the plates, which are 0.5 cm apart. Then the velocity of the cathode ray beam is (in ms−1).

A bullet with mass 200 gm and velocity vb m/s hits a ballistic pendulum bob of mass 800 gm and rises along with pendulum to a height h=0.2 m. Determine the value of vb. Take g=10 m/s2.

A rod of mass M and length L that is hinged about its end point is released from rest from horizontal position in a vertical plane as shown in figure. Hinge reaction when rod becomes vertical is pq Mg then p+q is (where p &amp; q are coprime)

A concave mirror of focal length 40cm forms a real image of an object of size 3 times size of object. Find out position of both object and image.

43. The de Broglie wavelength of a particle with mass1 g and velocity 100 m/s is(1) 6.63 x10^{-35}m(2) 6.63 x 10^{-34}m(3) 6.63x 10^{-33}m(4)6.65 x 10^{-35} m

When using high voltage to carry current over a large distance, wouldn't the heat loss be high too due to the equation P=V^2/R. Just like it is high for high values of I?

A block of weight W is kept on an inclined surface whose angle of inclination is θ with horizontal. The component of weight along the incline is

118. In the given figure current carrying conductor will

Consider a ring of mass m and radius r. Maximum gravitational intensity on the axis of the ring has the valu

36. Three infinitely long line charges having linear charge density A,2A,3Aare placed along x axis y axis and Z Axis respectively the work done by the electric field in moving a unit positive charge from (2,2,2) to (2,2,0) will be----

what is the correct relation for a solution 1) ψ w = ψ s + ψ p 2) ψ w = ψ s 3)ψ p =ψ s 4) no

In a double-slit experiment the angular width of a fringe is found to be 0.2° on a screen placed 1 m away. The wavelength of light used is 600 nm. What will be the angular width of the fringe if the entire experimental apparatus is immersed in water? Take refractive index of water to be 4/3.

consider a parallel plate capacitor with plate area A . A positive charge +Q is given to one plate and a negative charge -2Q is given to other plate . what is the force of inteaction between them

In the circuit shown in the figure, the input voltage Vi is 20 V, VBE=0 V and VCE=0 V. The value of IB is given by

Is it necessary that a measurement which is accurate must be precise or a measurement which is precise must be accurate?

{ The ratio of displacement in }n second and in the }}{n^ th } second for a particle moving in a straight line }} under constant acceleration starting from rest is

The vector →P=a^i+a^j+3^k and →Q=a^i−2^j−^k are perpendicular to each other. The positive value of a is

Two spherical bodies of mass m, 5m and radius R, 2R respectively are released in free space with an initial separation of 12R between their centres. If they attract each other due to gravitational force alone, then the distance covered by the smaller body just before the collision is

What are solid angles?

A vertical rod of length l is now moving with a constant velocity v towards east. the vertical component of Earth's magnetic field is B and angle of dip is theta . The induced EMF in the rod is : Blv sin theta Blv cos theta Blv cot theta Blv tan theta

An object looks red when seen through a piece of red glass. What is the actual colour of the object? (1)Red only (2)White only (3)Red or green (4)Black

19) a+b+c=0 find ( (b-c )/ a ​ + (c-a)/ b ​ + (a-b)/ c ​ )( c /(a-b )​ + a /(b-c) ​ + b/( c-a ​ )

A uniform rope of length l lies on a table. If the coefficient of friction is μ, then the maximum length l1 of the hanging part of the rope which can overhang from the edge of the table without sliding down is

If we place a bar magnet in the magnetic meridian with its north pole towards geographical North, the neutral point will be 1.on the axial of the magnet 2.on the equatorial line line of magnet 3.at 45 with the axial line 4. At 45 with equatorial line

A body of m is moving in a straight line at a constant speed v. Its kinetic energy is k and the magnitude of its momentum is p. Which of the following relations is/are correct?

A force acts on a 30 g particle in such a way that the position of the particle as a function of time is given by x=3t−4t2+t3, where x is in meters and t is in seconds. The work done during the first 4 seconds is

A laminar body is uniformly rotating about an axis fixed in an inertial frame of reference. Let →A be vector along the axis of rotation and →B be the unit vector along the resultant force on a particle P of the body away from the axis. The value of →A.→B is:

A partical is moving in the xy-plane has velocity components dx/dt =2t and dy/dt=4. If the partical start from the origin at t=0 , magnitude of its displacement at t=2s is

The degree of static indeterminacy of truss given below is.3

There is a horizontal film of soap solution. On it, a thread is placed in the form of a loop. The film is pierced inside the loop and the thread becomes a circular loop of radius R. if the surface tension of the loop be T, then what will be the tension in the thread?

A projectile is fired horizontally from an inclined plane of inclination 45 degree with horizontal with speed 50 m/s g=10 then range along incline is

The maximum height of an oblique projectile is 8 m. The horizontal range is 24 m. The horizontal component of the velocity of projection is

A galvanometer of resistance 95 Ω shunted by a resistance of 5 Ω gives a deflection of 50 divisions when joined in series with a resistance of 20 kΩ and a 2 V accumulator. What is the current sensitivity of the galvanometer in div/μA?

As shown in fig., two identical capacitors are connected to a battery of V volts in parallel. When capacitors are fully charged their energy is U1. If the key K is opened and a material of dielectric constant εr=2 is inserted in each capacitors their stored energy is now U2. Then, U1U2 will be

A long metallic rod along the E-W direction falls under gravity.potential difference between its two ends

Given that v is the speed, r is the radius and g is the acceleration due to gravity. Which of the following is dimensionless ?

Q15/15 A perfectly reflecting solid hemisphere of radius }R is placed } in the path of a parallel beam of light of large aperature. If the beam } carries an intensity }, the force exerted by the beam on the } hemisphere is

The magnitude of the force (in N) acting on a body varies with time t (in μs) as shown. AB,BC and CD are straight line segments. The magnitude of the total impule of the force on the body from t=4 μs to t=16 μs is

When a sinusoidal message signal is applied to the X-plates of a CRO and the corresponding amplitude modulated (AM) signal is applied to the y-plates, the X-Y plot displayed on the screen of the CRO is as shown in the figure below.The modulation index of the AM signal is equal to _____.1.67

Unpolarized light of intensity 32 Wm−2 passes through three polarizers arranged in a way, such that the transmission axis of the last polarizer is crossed with that of the first. If the intensity of emerging light is 3 Wm−2, what is the angle between the axis of first two polarizers?

A rod of mass M and length L that is hinged about its end point is released from rest from horizontal position in a vertical plane as shown in figure. Hinge reaction when rod becomes vertical is pq Mg then p+q is (where p & q are coprime)

19) a+b+c=0 find ( (b-c )/ a + (c-a)/ b + (a-b)/ c )( c /(a-b ) + a /(b-c) + b/( c-a )