50278 + Interview Questions in Physics Page 28 InterviewSolution

1351.	A particle start from rest with constant acceleration. The ratio of Space-average velocity to the time average velocity is : 1) 1/22) 3/4 3) 4/3 4) 3/2
Answer» A particle start from rest with constant acceleration. The ratio of Space-average velocity to the time average velocity is : 1) 1/2 2) 3/4 3) 4/3 4) 3/2

Discussion

1352.	is energy lost when a body is slipping (only angular velocity , no linear velocity )
Answer» is energy lost when a body is slipping (only angular velocity , no linear velocity )

Discussion

1353.	Q.An object 1cm high is place on theaxis and 15cm from a concave mirror of focal length 10cm.Find thwe position,nature,magnification and size of image?
Answer» Q.An object 1cm high is place on theaxis and 15cm from a concave mirror of focal length 10cm.Find thwe position,nature,magnification and size of image?

Discussion

1354.	In a system of units of force F, acceleration A and time T are taken as fundamental units, then the dimensional formula of energy is
Answer» In a system of units of force $F$ , acceleration $A$ and time $T$ are taken as fundamental units, then the dimensional formula of energy is

Discussion

1355.	A linear simple harmonic oscillation has a total energy of 250 J. If the potential energy at mean position is 50 J, then find the maximum kinetic energy.
Answer» A linear simple harmonic oscillation has a total energy of $250 J$ . If the potential energy at mean position is $50 J$ , then find the maximum kinetic energy.

Discussion

1356.	Find the vector parallel to the vector ^i−2^j and has magnitude 2√5 units.
Answer» Find the vector parallel to the vector $^i - 2^j$ and has magnitude $2 \sqrt{5}$ units.

Discussion

1357.	A ball is projected vertically from the ground upward. It takes 4S to reach at point P during upward motion. If it takes 10S more to reach the ground, then the point P is the height
Answer» A ball is projected vertically from the ground upward. It takes 4S to reach at point P during upward motion. If it takes 10S more to reach the ground, then the point P is the height

Discussion

1358.	A proton, a deuteron and an α-particle is accelerated through the same potential difference from rest, enters a region of uniform magnetic field, moving at right angles to it. What is the ratio of their kinetic energies?
Answer» A proton, a deuteron and an $α$ -particle is accelerated through the same potential difference from rest, enters a region of uniform magnetic field, moving at right angles to it. What is the ratio of their kinetic energies?

Discussion

1359.	For a point source of sound, the graph of intensity (I) versus square of distance from the source (r2) is best represented by
Answer» For a point source of sound, the graph of intensity $(I)$ versus square of distance from the source $(r^{2})$ is best represented by

Discussion

1360.	At constant volume the specific heat of a gas is 3R2, then the value of γ will be
Answer» At constant volume the specific heat of a gas is $\frac{3 R}{2}$ , then the value of $γ$ will be

Discussion

1361.	1 kg of ice at -10 degree celsius is mixed with 4.4 kg of water at 30 degree celsius. The final temperature of mixture is : (Specific heat of ice = 2100 J/kg-k) (1) 2.3 degree celsius (2) 4.4 degree celsius (3) 5.3 degree celsius (4) 8.7 degree celsius
Answer» 1 kg of ice at -10 degree celsius is mixed with 4.4 kg of water at 30 degree celsius. The final temperature of mixture is : (Specific heat of ice = 2100 J/kg-k) (1) 2.3 degree celsius (2) 4.4 degree celsius (3) 5.3 degree celsius (4) 8.7 degree celsius

Discussion

1362.	A body is thrown vertically upward with 55m/s (g=10). Distance travelled by the body in 6th second is
Answer» A body is thrown vertically upward with 55m/s (g=10). Distance travelled by the body in 6th second is

Discussion

1363.	A transmitting antenna at the top of a tower height 32m and that of the receiving is 50m what is the max. distance b/w them for satisfactory communication in LOSmode ?
Answer» A transmitting antenna at the top of a tower height 32m and that of the receiving is 50m what is the max. distance b/w them for satisfactory communication in LOSmode ?

Discussion

1364.	The specific resistance of manganin is 50×10−8 Ω m. The resistance of a manganin cube having length 50 cm is
Answer» The specific resistance of manganin is $50 \times 10^{- 8} Ω m$ . The resistance of a manganin cube having length 50 cm is

1364.

The specific resistance of manganin is 50×10−8 Ω m. The resistance of a manganin cube having length 50 cm is

Answer»

The specific resistance of manganin is

$50 \times 10^{- 8} Ω m$ .

The resistance of a manganin cube having length

50 cm is

Discussion

1365.	A tangential force of 10 N is applied on the periphery of a ring due to which it starts rotating about an axis through its centre and perpendicular to its plane. What is the work done by this force in rotating the ring by 45o? {R = 2m}.
Answer» A tangential force of 10 N is applied on the periphery of a ring due to which it starts rotating about an axis through its centre and perpendicular to its plane. What is the work done by this force in rotating the ring by $45^{o}$ ? {R = 2m}.

Discussion

1366.	working of electric motor
Answer» working of electric motor

Discussion

1367.	a conducting shell A having radius r is given charge Q initially. The shell A is connected to shell B of radius 2r via switch and conducting wire. The switch is closed at t=0, then final charge density on the shell b is( assumingseperation between A and B is very large)
Answer» a conducting shell A having radius r is given charge Q initially. The shell A is connected to shell B of radius 2r via switch and conducting wire. The switch is closed at t=0, then final charge density on the shell b is( assumingseperation between A and B is very large)

Discussion

1368.	A copper wire having resistance of 0.01 Ω is used to wind a 400 turns toroid of inner radius of 2 cm and outer radius of 3 cm. Find the emf of a battery which when connected across the toroid will create a magnetic field of 1.0×10−2 T at a distance equal to the mean radius of the toroid, from the center of the toroid.
Answer» A copper wire having resistance of $0.01 Ω$ is used to wind a $400$ turns toroid of inner radius of $2 cm$ and outer radius of $3 cm$ . Find the emf of a battery which when connected across the toroid will create a magnetic field of $1.0 \times 10^{- 2} T$ at a distance equal to the mean radius of the toroid, from the center of the toroid.

Discussion

1369.	Period of the function f(θ)=sinθ−√3cosθ is
Answer» Period of the function $f (θ) = sin θ - \sqrt{3} cos θ$ is

Discussion

1370.	A bar is subjected to equal and opposite forces as shown in the figure. PQRS is a plane making angle θ with the cross-section of the bar. If the area of cross-section be ‘A’, then when is the tensile stress maximum
Answer» A bar is subjected to equal and opposite forces as shown in the figure. PQRS is a plane making angle $θ$ with the cross-section of the bar. If the area of cross-section be ‘A’, then when is the tensile stress maximum

Discussion

1371.	In hexagonal system of crystals, a frequently encountered arrangement of atoms is described as a hexagonal prism. Here, the top and bottom of the cell arc regular hexagons and three atoms are sandwiched between them. A space-filling model of this structure, called hexagonal close packed (hcp), is constituted of a sphere on a flat surface surrounded in the same plane by six identical spheres as closely as possible. Three spheres are then placed over the first layer so that they touch each other and represent the second layer. Each one of these three spheres touches three spheres of the bottom layer. Finally, the second layer is covered with a third layer that is identical to the bottom layer in relative position. Assume radius of every sphere to be 'r'.The volume of this hcp unit cell is:
Answer» In hexagonal system of crystals, a frequently encountered arrangement of atoms is described as a hexagonal prism. Here, the top and bottom of the cell arc regular hexagons and three atoms are sandwiched between them. A space-filling model of this structure, called hexagonal close packed (hcp), is constituted of a sphere on a flat surface surrounded in the same plane by six identical spheres as closely as possible. Three spheres are then placed over the first layer so that they touch each other and represent the second layer. Each one of these three spheres touches three spheres of the bottom layer. Finally, the second layer is covered with a third layer that is identical to the bottom layer in relative position. Assume radius of every sphere to be 'r'. The volume of this hcp unit cell is:

Discussion

1372.	Two balls with equal charges are in a vessel with ice at −10∘C at a distance of 25 cm from each other. On forming water at 0∘C, the balls are brought nearer to 5 cm for the interaction between them to be the same. If the dielectric constant of water at 0∘C is 80. The dielectric constant of ice at −10∘C is-
Answer» Two balls with equal charges are in a vessel with ice at $- 10^{\circ} C$ at a distance of $25 cm$ from each other. On forming water at $0^{\circ} C,$ the balls are brought nearer to $5 cm$ for the interaction between them to be the same. If the dielectric constant of water at $0^{\circ} C$ is $80.$ The dielectric constant of ice at $- 10^{\circ} C$ is-

Discussion

1373.	As shown in fig. when a spherical cavity (centred at O) of radius 1 is cut out of a uniform sphere of radius R (centred at C) , the centre of mass of remaining (shaded) part of sphere is at G, i.e on the surface of the cavity. R can be determined by the equation
Answer» As shown in fig. when a spherical cavity $(centred at O)$ of radius $1$ is cut out of a uniform sphere of radius $R$ $(centred at C)$ , the centre of mass of remaining (shaded) part of sphere is at $G$ , i.e on the surface of the cavity. $R$ can be determined by the equation

Discussion

1374.	4. A disc of radius R rotates fro rest about a vertical axis with a constant angular acce. Such that coin placed at the periphery of the disc moves with tangential acc a. If the coefficient of static friction is $ fi d the distance travelled and the time taken before sliding?
Answer» 4. A disc of radius R rotates fro rest about a vertical axis with a constant angular acce. Such that coin placed at the periphery of the disc moves with tangential acc a. If the coefficient of static friction is $ fi d the distance travelled and the time taken before sliding?

Discussion

1375.	A car moving with a speed of 50 km/h can be stopped by applying brakes after at least 10 m. What will the minimum stopping distance if the same car is moving at a speed of 100 km/h?
Answer» A car moving with a speed of 50 km/h can be stopped by applying brakes after at least 10 m. What will the minimum stopping distance if the same car is moving at a speed of 100 km/h?

Discussion

1376.	A disc is freely rotating with an angular speed ω on a smooth horizontal plane. If it is hooked at a rigid point P(near to its circumference) and rotates without bouncing about P. Its angular speed after the impact will be equal to ωn, value of n is
Answer» A disc is freely rotating with an angular speed $ω$ on a smooth horizontal plane. If it is hooked at a rigid point $P$ (near to its circumference) and rotates without bouncing about $P$ . Its angular speed after the impact will be equal to $\frac{ω}{n},$ value of $n$ is

Discussion

1377.	If the highest frequency modulating a carrier is 5 kHz, then the number of AM broadcast stations accommodated in a 90 kHz bandwidth are ______.
Answer» If the highest frequency modulating a carrier is $5 kHz$ , then the number of $A M$ broadcast stations accommodated in a $90 kHz$ bandwidth are ______.

Discussion

1378.	A rigid spherical body is spinning around an axis without any external torque. Due to temperature its volume increases by 3%. Then percentage change in its angular speed is
Answer» A rigid spherical body is spinning around an axis without any external torque. Due to temperature its volume increases by 3%. Then percentage change in its angular speed is

Discussion

1379.	In a young’s double slit experiment, D equals the distance of screen from the plane of slits and d is the separation between the slits. The distance of the nearest point from the central maximum on the screen, where the intensity is same as that due to a single slit, is equal toGiven that dD=10−4,λ=6000 ˙A
Answer» In a young’s double slit experiment, $D$ equals the distance of screen from the plane of slits and $d$ is the separation between the slits. The distance of the nearest point from the central maximum on the screen, where the intensity is same as that due to a single slit, is equal to Given that $\frac{d}{D} = 10^{- 4}, λ = 6000 ˙ A$

Discussion

1380.	Consider the set up shown, where we have an ideal gas trapped in a cylindrical container, kept on a thermal reservoir which provides heat to the system. The weight on top maintains a constant pressure P on the gas. Supplying heat Q changes the temperature by ΔT, and expands the volume by ΔV. The expanding gas displaces the container and does work, W. Choose the correct inferences from the following options
Answer» Consider the set up shown, where we have an ideal gas trapped in a cylindrical container, kept on a thermal reservoir which provides heat to the system. The weight on top maintains a constant pressure P on the gas. Supplying heat Q changes the temperature by $Δ T$ , and expands the volume by $Δ V$ . The expanding gas displaces the container and does work, W. Choose the correct inferences from the following options

1380.

Consider the set up shown, where we have an ideal gas trapped in a cylindrical container, kept on a thermal reservoir which provides heat to the system. The weight on top maintains a constant pressure P on the gas. Supplying heat Q changes the temperature by ΔT, and expands the volume by ΔV. The expanding gas displaces the container and does work, W. Choose the correct inferences from the following options

Answer»

Consider the set up shown, where we have an ideal gas trapped in a cylindrical container, kept on a thermal reservoir which provides heat to the system. The weight on top maintains a constant pressure P on the gas. Supplying heat Q changes the temperature by $Δ T$ , and expands the volume by $Δ V$ . The expanding gas displaces the container and does work, W. Choose the correct inferences from the following options

Discussion

1381.	On a two-lane road, car A is travelling with a speed of v=5 ms−1. Two cars, B and C approach car A in opposite directions with a speed of u=10 ms−1 each. At a certain instant when the B and C are equidistant from A each being l=1500 m, B decides to overtake A before C passes A. What minimum acceleration(in m/s2) of car B is required to avoid an accident with C ?
Answer» On a two-lane road, car A is travelling with a speed of $v = 5 {ms}^{- 1}$ . Two cars, B and C approach car A in opposite directions with a speed of $u = 10 {ms}^{- 1}$ each. At a certain instant when the B and C are equidistant from A each being $l = 1500 m$ , B decides to overtake A before C passes A. What minimum acceleration(in ${m/s}^{2}$ ) of car B is required to avoid an accident with C ?

Discussion

1382.	11.A telescope has an objective of focal length 50cm and eye piece of focal length 5cm .the least distance of distinct vision is 25cm .the telescope is focussed for distinct vision on a scale 200cm away from the objective . calculate the separation between objective and eye piece lens and magnification produced.
Answer» 11.A telescope has an objective of focal length 50cm and eye piece of focal length 5cm .the least distance of distinct vision is 25cm .the telescope is focussed for distinct vision on a scale 200cm away from the objective . calculate the separation between objective and eye piece lens and magnification produced.

Discussion

1383.	A ball is thrown upwards from the ground with an initial velocity u . The ball is at a height of 80m at two times, the time interval being 6s. Find u ?
Answer» A ball is thrown upwards from the ground with an initial velocity u . The ball is at a height of 80m at two times, the time interval being 6s. Find u ?

Discussion

1384.	In the given circuit with the steady current, the potential drop across the capacitor must be
Answer» In the given circuit with the steady current, the potential drop across the capacitor must be

Discussion

1385.	2. A monkey is climbing on a rope that goes over a smooth light pulley and supports a block of equal mass at other end. Show that whatever force monkey exerts on rope, the monkey and the block move in same direction with equal acceleration. If initially both were at rest, their separation will not change as time
Answer» 2. A monkey is climbing on a rope that goes over a smooth light pulley and supports a block of equal mass at other end. Show that whatever force monkey exerts on rope, the monkey and the block move in same direction with equal acceleration. If initially both were at rest, their separation will not change as time

Discussion

1386.	39. A point charge Q = -8 nC is located at the origin. The electric field at the point x=1.2 m and y=-1.6 m as shown in the figure is
Answer» 39. A point charge Q = -8 nC is located at the origin. The electric field at the point x=1.2 m and y=-1.6 m as shown in the figure is

Discussion

1387.	In the diagram there are four conducting plates A, B, C and D placed parallel to each other at equal separation L. If plate C starts moving towards plate B with velocity v. Find the current (in mA) flowing in the wire connecting A and D. (assume all other plates to be fixed) (Given: q2=2μC, q3=3μC, v=10 m/s, L=0.05 m)
Answer» In the diagram there are four conducting plates A, B, C and D placed parallel to each other at equal separation L. If plate C starts moving towards plate B with velocity v. Find the current (in mA) flowing in the wire connecting A and D. (assume all other plates to be fixed) (Given: $q_{2} = 2 μ C, q_{3} = 3 μ C, v = 10 m / s, L = 0.05 m$ )

Discussion

1388.	The armature current in a dc motor is maximum when the motor has
Answer» The armature current in a dc motor is maximum when the motor has

Discussion

1389.	the equation of plain progressive wave is y = 20sin (100πt-2πx) the velocity of medium particle at x=1/6 and at t=0 is
Answer» the equation of plain progressive wave is y = 20sin (100πt-2πx) the velocity of medium particle at x=1/6 and at t=0 is

Discussion

1390.	A block of mass 2kg slipped up a slant plane requires 300j of work. If height of slant is 10m the work done against friction is-
Answer» A block of mass 2kg slipped up a slant plane requires 300j of work. If height of slant is 10m the work done against friction is-

Discussion

1391.	Compute the typical de Broglie wavelength of an electron in a metal at 27 °C and compare it with the mean separation between two electrons in a metal which is given to be about 2 × 10–10 m. [Note: Exercises 11.35 and 11.36 reveal that while the wave-packets associated with gaseous molecules under ordinary conditions are non-overlapping, the electron wave-packets in a metal strongly overlap with one another. This suggests that whereas molecules in an ordinary gas can be distinguished apart, electrons in a metal cannot be distintguished apart from one another. This indistinguishibility has many fundamental implications which you will explore in more advanced Physics courses.]
Answer» Compute the typical de Broglie wavelength of an electron in a metal at 27 °C and compare it with the mean separation between two electrons in a metal which is given to be about 2 × 10–10 m. [Note: Exercises 11.35 and 11.36 reveal that while the wave-packets associated with gaseous molecules under ordinary conditions are non-overlapping, the electron wave-packets in a metal strongly overlap with one another. This suggests that whereas molecules in an ordinary gas can be distinguished apart, electrons in a metal cannot be distintguished apart from one another. This indistinguishibility has many fundamental implications which you will explore in more advanced Physics courses.]

Discussion

1392.	If a 5 cm long capillary tube with 0.2 mm internal diameter open at both ends is slightly dipped in water having surface tension 75 dyne/cm. What will be the rise of water in capillary (Take g=1000 cm/s2)
Answer» If a $5 cm$ long capillary tube with $0.2 mm$ internal diameter open at both ends is slightly dipped in water having surface tension $75 dyne/cm$ . What will be the rise of water in capillary $($ Take $g = 1000 cm / s^{2}$ $)$

Discussion

1393.	The number of protons, neutrons and electrons in 17571Lu respectively, are
Answer» The number of protons, neutrons and electrons in $_{71}^{175} L u$ respectively, are

Discussion

1394.	The driver of a three-wheeler moving with a speed of 36 km/h sees a child standing in the middle of the road and brings his vehicle to rest in 4.0 s just in time to save the child. What is the average retarding force on the vehicle ? The mass of the three-wheeler is 400 kg and the mass of the driver is 65 kg.
Answer» The driver of a three-wheeler moving with a speed of 36 km/h sees a child standing in the middle of the road and brings his vehicle to rest in 4.0 s just in time to save the child. What is the average retarding force on the vehicle ? The mass of the three-wheeler is 400 kg and the mass of the driver is 65 kg.

Discussion

1395.	a solid metallic cuboid of homogenous material having geometrical dimension as shown in the figure will have a ratio of resistances for the sense of current along x, y and z directions respectively equal to
Answer» a solid metallic cuboid of homogenous material having geometrical dimension as shown in the figure will have a ratio of resistances for the sense of current along x, y and z directions respectively equal to

Discussion

1396.	A source is moving along a circle given by the equation x2 + y2 = R2, with cons†an t speed , in anti-clockwise sense. A detector is at rest at point (2R, 0) w.r.t. the centre of the circle. If the frequency emitted by the source is f and the speed of sound, C = 330 m/s. Then the position of the source when the detecter records maximum and minimum frequencies and the value of min and max frequencies.
Answer» A source is moving along a circle given by the equation x2 + y2 = R2, with cons†an t speed , in anti-clockwise sense. A detector is at rest at point (2R, 0) w.r.t. the centre of the circle. If the frequency emitted by the source is f and the speed of sound, C = 330 m/s. Then the position of the source when the detecter records maximum and minimum frequencies and the value of min and max frequencies.

Discussion

1397.	Photoelectrons are liberated by ultravioletlight of wavelength 3000from a metallic surface for which thephotoelectric threshold is 4000. The de-broglie wavelength of electron emittedwith maximum kinetic energy is
Answer» Photoelectrons are liberated by ultraviolet light of wavelength 3000from a metallic surface for which the photoelectric threshold is 4000. The de-broglie wavelength of electron emitted with maximum kinetic energy is

1397.

Photoelectrons are liberated by ultravioletlight of wavelength 3000from a metallic surface for which thephotoelectric threshold is 4000. The de-broglie wavelength of electron emittedwith maximum kinetic energy is

Answer»

Photoelectrons are liberated by ultraviolet
light of wavelength 3000from a metallic surface for which the
photoelectric threshold is 4000. The de-broglie wavelength of electron emitted
with maximum kinetic energy is

Discussion

1398.	22.A force f =5t is applied to a particle of mass 10kg kept on a rough horizontal surface having coefficient of friction 0.5 in rest what is the speed of block at t=20 second
Answer» 22.A force f =5t is applied to a particle of mass 10kg kept on a rough horizontal surface having coefficient of friction 0.5 in rest what is the speed of block at t=20 second

Discussion

1399.	A steel wire is drawn from an initial diameter (di) of 10 mm to a final diameter (df) of 7.5 mm. The half cone angle (α) of the die is 5∘ and the coefficient of friction (μ) between the die and the wire is 0.1. The average of the initial and final yield stress [(σy)avg] is 350 MPa. The equation for drawing stress σf. (in MPa) is given as:σf=(σy)avg{1+1μcotα}[1−(dfdi)2μcotα]The drawing stress (in MPa) required to carry out this operation is (correct to two decimal places).
Answer» A steel wire is drawn from an initial diameter $(d_{i})$ of 10 mm to a final diameter $(d_{f})$ of 7.5 mm. The half cone angle $(α)$ of the die is $5^{\circ}$ and the coefficient of friction $(μ)$ between the die and the wire is 0.1. The average of the initial and final yield stress $[(σ_{y})_{a v g}]$ is 350 MPa. The equation for drawing stress $σ_{f}$ . (in MPa) is given as: $σ_{f} = (σ_{y})_{a v g} {1 + \frac{1}{μ c o t α}} [1 - {(\frac{d_{f}}{d_{i}})}^{2 μ c o t α}]$ The drawing stress (in MPa) required to carry out this operation is (correct to two decimal places).

Discussion

1400.	The tuning circuit of a radio receiver has a resistance of 50 Ω, an inductor of 10 mH and a variable capacitor. A 1 MHz radio wave produces a potential difference of 0.1 mV. The value of the capacitor to produce the resonance is (take π2=10)
Answer» The tuning circuit of a radio receiver has a resistance of $50 Ω$ , an inductor of $10 mH$ and a variable capacitor. A $1 MHz$ radio wave produces a potential difference of $0.1 mV .$ The value of the capacitor to produce the resonance is $($ take $π^{2} = 10)$

Discussion

Explore topic-wise InterviewSolutions in .

A particle start from rest with constant acceleration. The ratio of Space-average velocity to the time average velocity is : 1) 1/22) 3/4 3) 4/3 4) 3/2

is energy lost when a body is slipping (only angular velocity , no linear velocity )

Q.An object 1cm high is place on theaxis and 15cm from a concave mirror of focal length 10cm.Find thwe position,nature,magnification and size of image?

In a system of units of force F, acceleration A and time T are taken as fundamental units, then the dimensional formula of energy is

A linear simple harmonic oscillation has a total energy of 250 J. If the potential energy at mean position is 50 J, then find the maximum kinetic energy.

Find the vector parallel to the vector ^i−2^j and has magnitude 2√5 units.

A ball is projected vertically from the ground upward. It takes 4S to reach at point P during upward motion. If it takes 10S more to reach the ground, then the point P is the height

A proton, a deuteron and an α-particle is accelerated through the same potential difference from rest, enters a region of uniform magnetic field, moving at right angles to it. What is the ratio of their kinetic energies?

For a point source of sound, the graph of intensity (I) versus square of distance from the source (r2) is best represented by

At constant volume the specific heat of a gas is 3R2, then the value of γ will be

1 kg of ice at -10 degree celsius is mixed with 4.4 kg of water at 30 degree celsius. The final temperature of mixture is : (Specific heat of ice = 2100 J/kg-k) (1) 2.3 degree celsius (2) 4.4 degree celsius (3) 5.3 degree celsius (4) 8.7 degree celsius

A body is thrown vertically upward with 55m/s (g=10). Distance travelled by the body in 6th second is

A transmitting antenna at the top of a tower height 32m and that of the receiving is 50m what is the max. distance b/w them for satisfactory communication in LOSmode ?

The specific resistance of manganin is 50×10−8 Ω m. The resistance of a manganin cube having length 50 cm is

A tangential force of 10 N is applied on the periphery of a ring due to which it starts rotating about an axis through its centre and perpendicular to its plane. What is the work done by this force in rotating the ring by 45o? {R = 2m}.

working of electric motor

a conducting shell A having radius r is given charge Q initially. The shell A is connected to shell B of radius 2r via switch and conducting wire. The switch is closed at t=0, then final charge density on the shell b is( assumingseperation between A and B is very large)

Period of the function f(θ)=sinθ−√3cosθ is

A bar is subjected to equal and opposite forces as shown in the figure. PQRS is a plane making angle θ with the cross-section of the bar. If the area of cross-section be ‘A’, then when is the tensile stress maximum

As shown in fig. when a spherical cavity (centred at O) of radius 1 is cut out of a uniform sphere of radius R (centred at C) , the centre of mass of remaining (shaded) part of sphere is at G, i.e on the surface of the cavity. R can be determined by the equation

4. A disc of radius R rotates fro rest about a vertical axis with a constant angular acce. Such that coin placed at the periphery of the disc moves with tangential acc a. If the coefficient of static friction is $ fi d the distance travelled and the time taken before sliding?

A car moving with a speed of 50 km/h can be stopped by applying brakes after at least 10 m. What will the minimum stopping distance if the same car is moving at a speed of 100 km/h?

A disc is freely rotating with an angular speed ω on a smooth horizontal plane. If it is hooked at a rigid point P(near to its circumference) and rotates without bouncing about P. Its angular speed after the impact will be equal to ωn, value of n is

If the highest frequency modulating a carrier is 5 kHz, then the number of AM broadcast stations accommodated in a 90 kHz bandwidth are ______.

A rigid spherical body is spinning around an axis without any external torque. Due to temperature its volume increases by 3%. Then percentage change in its angular speed is

A ball is thrown upwards from the ground with an initial velocity u . The ball is at a height of 80m at two times, the time interval being 6s. Find u ?

In the given circuit with the steady current, the potential drop across the capacitor must be

39. A point charge Q = -8 nC is located at the origin. The electric field at the point x=1.2 m and y=-1.6 m as shown in the figure is

The armature current in a dc motor is maximum when the motor has

the equation of plain progressive wave is y = 20sin (100πt-2πx) the velocity of medium particle at x=1/6 and at t=0 is

A block of mass 2kg slipped up a slant plane requires 300j of work. If height of slant is 10m the work done against friction is-

If a 5 cm long capillary tube with 0.2 mm internal diameter open at both ends is slightly dipped in water having surface tension 75 dyne/cm. What will be the rise of water in capillary (Take g=1000 cm/s2)

The number of protons, neutrons and electrons in 17571Lu respectively, are

a solid metallic cuboid of homogenous material having geometrical dimension as shown in the figure will have a ratio of resistances for the sense of current along x, y and z directions respectively equal to

Photoelectrons are liberated by ultravioletlight of wavelength 3000from a metallic surface for which thephotoelectric threshold is 4000. The de-broglie wavelength of electron emittedwith maximum kinetic energy is

22.A force f =5t is applied to a particle of mass 10kg kept on a rough horizontal surface having coefficient of friction 0.5 in rest what is the speed of block at t=20 second

The tuning circuit of a radio receiver has a resistance of 50 Ω, an inductor of 10 mH and a variable capacitor. A 1 MHz radio wave produces a potential difference of 0.1 mV. The value of the capacitor to produce the resonance is (take π2=10)