50278 + Interview Questions in Physics

1.	Two thermally insulated vessels 1 and 2 are filled with air at temperatures (T1,T2), volume (V1,V2) and pressure (P1,P2) respectively. If the valve joining the two vessels is opened, the temperature inside the vessel at equilibrium will be
Answer» Two thermally insulated vessels 1 and 2 are filled with air at temperatures $(T_{1}, T_{2})$ , volume $(V_{1}, V_{2})$ and pressure $(P_{1}, P_{2})$ respectively. If the valve joining the two vessels is opened, the temperature inside the vessel at equilibrium will be

Discussion

2.	The time taken by a body to slide down a rough 45∘ inclined plane is thrice of that is required to slide down a smooth 45∘ inclined plane. The coefficient of kinetic friction between the object and rough plane is given by:
Answer» The time taken by a body to slide down a rough $45^{\circ}$ inclined plane is thrice of that is required to slide down a smooth $45^{\circ}$ inclined plane. The coefficient of kinetic friction between the object and rough plane is given by:

Discussion

3.	ntn ntQ. If R & H are the horizontal range and maximum height attained by a projectile, than its speed of projection isn nt1) 2gR + 4R2/gHn nt2) 2gH + R2g/8Hn nt3) 2gH + 8H/Rgn nt4) 2gH + R2/Hn
Answer» ntn ntQ. If R & H are the horizontal range and maximum height attained by a projectile, than its speed of projection isn nt1) 2gR + 4R2/gHn nt2) 2gH + R2g/8Hn nt3) 2gH + 8H/Rgn nt4) 2gH + R2/Hn

Discussion

4.	An ISLB 350 486 N/m beam is laterally supported throughout. The following properties are given for the I - sectionIx=13158.3×104mm4, shape factor =1.12,fy=250MPa,γmo=1.1Assume the section to be a compact section and a case of low shear. The design bending strength will be kNm.191.39
Answer» An ISLB 350 486 N/m beam is laterally supported throughout. The following properties are given for the I - section $I_{x} = 13158.3 \times 10^{4} m m^{4},$ shape factor $= 1.12, f_{y} = 250 M P a, γ_{m o} = 1.1$ Assume the section to be a compact section and a case of low shear. The design bending strength will be kNm. 191.39

4.

An ISLB 350 486 N/m beam is laterally supported throughout. The following properties are given for the I - sectionIx=13158.3×104mm4, shape factor =1.12,fy=250MPa,γmo=1.1Assume the section to be a compact section and a case of low shear. The design bending strength will be kNm.191.39

Answer»

An ISLB 350 486 N/m beam is laterally supported throughout. The following properties are given for the I - section

$I_{x} = 13158.3 \times 10^{4} m m^{4},$ shape factor $= 1.12, f_{y} = 250 M P a, γ_{m o} = 1.1$

Assume the section to be a compact section and a case of low shear. The design bending strength will be kNm.

191.39

Discussion

5.	A second's pendulum is placed in a spacelaboratory orbiting around the earth at a height of3R, where R is the radius of earth. The time periodof the pendulum is
Answer» A second's pendulum is placed in a spacelaboratory orbiting around the earth at a height of3R, where R is the radius of earth. The time periodof the pendulum is

Discussion

6.	A car of mass m is accelerated on a plane road under the influence of a force in such a way that its velocity becomes v2 from v1 in a distance s. If a constant power P is generated by the car engine, then the velocity v2 will be
Answer» A car of mass $m$ is accelerated on a plane road under the influence of a force in such a way that its velocity becomes $v_{2}$ from $v_{1}$ in a distance $s$ . If a constant power $P$ is generated by the car engine, then the velocity $v_{2}$ will be

Discussion

7.	a ball of mass m is thrown upward and another ball ofsame mass is thrown downward so as to move freely under gravity . The acceleration of centre of mass is
Answer» a ball of mass m is thrown upward and another ball ofsame mass is thrown downward so as to move freely under gravity . The acceleration of centre of mass is

Discussion

8.	An atom has weight of 7×10−9 lb. What will be the weight of 106atoms?
Answer» An atom has weight of $7 \times 10^{- 9}$ lb. What will be the weight of $10^{6}$ atoms?

Discussion

9.	nttwo charged capacitor have their outer plates fixed and inner plates connected by a spring of force constant k. the charge on each capacitor is q. find the extension in the string at equilibrium?n
Answer» nttwo charged capacitor have their outer plates fixed and inner plates connected by a spring of force constant k. the charge on each capacitor is q. find the extension in the string at equilibrium?n

Discussion

10.	The given figure shows a set of equipotential surfaces. Find the magnitude and direction of electric field that exists in the region.
Answer» The given figure shows a set of equipotential surfaces. Find the magnitude and direction of electric field that exists in the region.

Discussion

11.	Two similar 400 V, 3-phase alternators share equal kW power delivered to a balanced three phase, 50 kW, 0.8 p.f. lagging load. If the power factor of one machine is 0.9 lag, then the current supplied by other machine is _____A.51.47
Answer» Two similar 400 V, 3-phase alternators share equal kW power delivered to a balanced three phase, 50 kW, 0.8 p.f. lagging load. If the power factor of one machine is 0.9 lag, then the current supplied by other machine is _____A. 51.47

Discussion

12.	Cube of side ‘a’. Find net force on one of the charges due to the presence of ether charges.
Answer» Cube of side ‘a’. Find net force on one of the charges due to the presence of ether charges.

Discussion

13.	A steel wire having a radius of 2.0 mm, carrying a load of 4 kg, is hanging from a ceiling. Given that g=3.1π ms−2, what will be the tensile stress that would be developed in the wire?
Answer» A steel wire having a radius of $2.0 m m$ , carrying a load of $4 k g$ , is hanging from a ceiling. Given that $g = 3.1 π m s^{- 2}$ , what will be the tensile stress that would be developed in the wire?

Discussion

14.	Three identical bulbs are connected as shown in figure. When switch S is open, the power consumed in bulb B is P. What will be the power consumed by the same bulb when switch S is closed?
Answer» Three identical bulbs are connected as shown in figure. When switch $S$ is open, the power consumed in bulb $B$ is $P$ . What will be the power consumed by the same bulb when switch $S$ is closed?

Discussion

15.	Magnetic flux linked with inductor increase from 0 to x and current in inductor increase from 0 to y magnetic energy stored in inductor is.
Answer» Magnetic flux linked with inductor increase from 0 to x and current in inductor increase from 0 to y magnetic energy stored in inductor is.

Discussion

16.	A star initially has 1040 deuterons. It produces energy via the processes1H2+1H2→1H3+p and 1H2+1H3→2He4+n. If the average power radiated by the star is 1016 W, the deuteron supply of the star is exhausted in a time of the order of 11.6×10x s. Then the value of x is (Integer only)Take m(1H2)=2.0141u, m(2He4)=4.0026u, m(1p1)=1.0078u, m(0n1)=1.0086u1u c2=931.5 MeV
Answer» A star initially has $10^{40}$ deuterons. It produces energy via the processes $_{1} H^{2} +_{1} H^{2} \to_{1} H^{3} + p and_{1} H^{2} +_{1} H^{3} \to_{2} {He}^{4} + n$ . If the average power radiated by the star is $10^{16} W$ , the deuteron supply of the star is exhausted in a time of the order of $11.6 \times 10^{x} s$ . Then the value of $x$ is (Integer only) $Take m (_{1} H^{2}) = 2.0141 u, m (_{2} {He}^{4}) = 4.0026 u, m (_{1} p^{1}) = 1.0078 u, m (_{0} n^{1}) = 1.0086 u 1 u c^{2} = 931.5 MeV$

Discussion

17.	A string of linear mass density 0.5 g cm−1 and a total length 30 cm is tied to a fixed wall at one end and to a frictionless ring at the other end. The ring can move on a vertical rod. A wave pulse is produced on the string which moves towards the ring at a speed of 20 cms−1. The pulse is symmetric about its maximum which is located at a distance of 20 cm from the end joined to the ring. Assuming that the wave is reflected from the ends without loss of energy, find the time taken by the string to regain its shape.
Answer» A string of linear mass density $0.5 g c m^{- 1}$ and a total length $30 c m$ is tied to a fixed wall at one end and to a frictionless ring at the other end. The ring can move on a vertical rod. A wave pulse is produced on the string which moves towards the ring at a speed of $20 c m s^{- 1}$ . The pulse is symmetric about its maximum which is located at a distance of $20 c m$ from the end joined to the ring. Assuming that the wave is reflected from the ends without loss of energy, find the time taken by the string to regain its shape.

Discussion

18.	A simple harmonic wave of amplitude 2 units is travelling along x - axis. At a given instant, displacements for two different particles on the wave are 1 unit and √2 units. If the wavelength of wave is λ, find the distance between them.
Answer» A simple harmonic wave of amplitude 2 units is travelling along x - axis. At a given instant, displacements for two different particles on the wave are 1 unit and $\sqrt{2}$ units. If the wavelength of wave is $λ$ , find the distance between them.

Discussion

19.	A cylindrical piece of cork of density of base area A and height h floats in a liquid of density p₁. The cork is depressed slightly and then released. Show that the cork oscillates up and down simple harmonically with a period T= 2 π √( hp/p₁/g) where r is the density of cork. (Ignore damping due to viscosity of the liquid).
Answer» A cylindrical piece of cork of density of base area A and height h floats in a liquid of density p₁. The cork is depressed slightly and then released. Show that the cork oscillates up and down simple harmonically with a period T= 2 π √( hp/p₁/g) where r is the density of cork. (Ignore damping due to viscosity of the liquid).

Discussion

20.	A boy standing on a long railroad car throws a ball straight upwards. The car is moving on the horizontal road with an acceleration of 1 m/s2 and the projection speed in the vertical direction is 9.8 m/s. How far behind the boy will the ball fall on the car?
Answer» A boy standing on a long railroad car throws a ball straight upwards. The car is moving on the horizontal road with an acceleration of $1 m / s^{2}$ and the projection speed in the vertical direction is $9.8 m / s$ . How far behind the boy will the ball fall on the car?

Discussion

21.	the work functionof a surface of a photosensitive material is 6.2eV. The wavelength of the incident radiationfor which the stopping potential is 5
Answer» the work functionof a surface of a photosensitive material is 6.2eV. The wavelength of the incident radiationfor which the stopping potential is 5

Discussion

22.	A particle of mass M at rest decays into two particles of masses m1 and m2, having non-zero velocities. The ratio of the de-Broglie wavelengths of the particles, λ1λ2 is
Answer» A particle of mass M at rest decays into two particles of masses $m_{1}$ and $m_{2}$ , having non-zero velocities. The ratio of the de-Broglie wavelengths of the particles, $\frac{λ_{1}}{λ_{2}}$ is

Discussion

23.	Derive the equation of motion in algebraic method?
Answer» Derive the equation of motion in algebraic method?

Discussion

24.	An Am signal is modulated by 50% such that FOM of AM. becomes equal to the Figure of ment (FOM) of FM signal is FM modulated. The modulation index of FM will be _________0.272
Answer» An Am signal is modulated by 50% such that FOM of AM. becomes equal to the Figure of ment (FOM) of FM signal is FM modulated. The modulation index of FM will be _________ 0.272

Discussion

25.	Two electric dipole of moment p and 64p are placed in opposite directions on a line at a distance of 25 cm. The electric field will be zero at point between the dipoles whose distance from the dipole of moment p is
Answer» Two electric dipole of moment p and 64p are placed in opposite directions on a line at a distance of 25 cm. The electric field will be zero at point between the dipoles whose distance from the dipole of moment p is

Discussion

26.	If a particle is projected at t=0 from ground with speed u= 20 m/s at an angle of 45^° from horizontal then find the ratio of time of flight to the time interval in which velocity of particle becomes perpendicular to initial velocity of projection -
Answer» If a particle is projected at t=0 from ground with speed u= 20 m/s at an angle of 45^° from horizontal then find the ratio of time of flight to the time interval in which velocity of particle becomes perpendicular to initial velocity of projection -

Discussion

27.	Kirchhoff’s junction law is a consequence of which of the following law(s)?
Answer» Kirchhoff’s junction law is a consequence of which of the following law(s)?

Discussion

28.	Work done in increasing the size of a soap bubble from a radius of 3 cm to 5 cm is nearly (surface tension of soap solution = 0.03 Nm-1
Answer» Work done in increasing the size of a soap bubble from a radius of 3 cm to 5 cm is nearly (surface tension of soap solution = 0.03 Nm^-1

Discussion

29.	A point charge Q is located at the centre of a cube of edge length a. The total electric flux through one of the face of the cube is
Answer» A point charge $Q$ is located at the centre of a cube of edge length $a$ . The total electric flux through one of the face of the cube is

Discussion

30.	A particle of mass 2kg moves with an initial velocity u=(4i+4j)m/s.A constant force of F=-20j N is applied on the particle. Initially the particle was at (0,0). The x-coordinate of the particle when its y coordinate again becomes zero is given by
Answer» A particle of mass 2kg moves with an initial velocity u=(4i+4j)m/s.A constant force of F=-20j N is applied on the particle. Initially the particle was at (0,0). The x-coordinate of the particle when its y coordinate again becomes zero is given by

Discussion

31.	The number density of free electrons in a copper conductorestimated in Example 3.1 is 8.5 × 1028 m–3. How long does an electrontake to drift from one end of a wire 3.0 m long to its other end? Thearea of cross-section of the wire is 2.0 × 10–6 m2 and it is carrying acurrent of 3.0 A.
Answer» The number density of free electrons in a copper conductorestimated in Example 3.1 is 8.5 × 1028 m–3. How long does an electrontake to drift from one end of a wire 3.0 m long to its other end? Thearea of cross-section of the wire is 2.0 × 10–6 m2 and it is carrying acurrent of 3.0 A.

Discussion

32.	An electric dipole of moment P is released in a uniform electric field E from the position of maximum torque. Angular velocity of the dipole when P becomes parallel to E will be (I= moment of inertia of dipole) A) √2PE/IB) √PE/IC) √4PE/ID) √2I/PE
Answer» An electric dipole of moment P is released in a uniform electric field E from the position of maximum torque. Angular velocity of the dipole when P becomes parallel to E will be (I= moment of inertia of dipole) A) √2PE/I B) √PE/I C) √4PE/I D) √2I/PE

Discussion

33.	In wavy curve method from which side we shall start drawing the wave (upward or downeard side)?
Answer» In wavy curve method from which side we shall start drawing the wave (upward or downeard side)?

Discussion

34.	To which part of the electromagnetic spectrum does a wave of frequency 5×1019 Hz belong?
Answer» To which part of the electromagnetic spectrum does a wave of frequency $5 \times 10^{19} H z$ belong?

Discussion

35.	In a resonance column experiment, a tuning fork of frequency 400 Hz is used. The first resonance is observed when the air column has a length 20.0 cm and the second resonance is observed when the air column has a length of 62.0 cm. Find the distance above the open end where the pressure node is formed ?
Answer» In a resonance column experiment, a tuning fork of frequency $400 Hz$ is used. The first resonance is observed when the air column has a length $20.0 cm$ and the second resonance is observed when the air column has a length of $62.0 cm$ . Find the distance above the open end where the pressure node is formed ?

Discussion

36.	A 100 W resistor is connected to a 220 V, 50 Hz ac supply. (a) What is the rms value of current in the circuit? (b) What is the net power consumed over a full cycle?
Answer» A 100 W resistor is connected to a 220 V, 50 Hz ac supply. (a) What is the rms value of current in the circuit? (b) What is the net power consumed over a full cycle?

Discussion

37.	35.A man of mass M stands on a platform of mass m and pulls himself up by pulley arrangement shown in the figure. If he pulls each rope with force F determine the upward acceleration
Answer» 35.A man of mass M stands on a platform of mass m and pulls himself up by pulley arrangement shown in the figure. If he pulls each rope with force F determine the upward acceleration

Discussion

38.	When a beam of 10.6 eV photons of intensity falls on a platinum surface of area 1.0×10−4 m2 and work function 5.6 eV. If 53% of the incident photon eject photoelectrons. Total photoelectrons emitting per second is n×1011. Find n(integer only)
Answer» When a beam of $10.6 eV$ photons of intensity falls on a platinum surface of area $1.0 \times 10^{- 4} m^{2}$ and work function $5.6 eV .$ If $53 %$ of the incident photon eject photoelectrons. Total photoelectrons emitting per second is $n \times 10^{11}$ . Find $n$ (integer only)

Discussion

39.	A monochromatic beam of light is incident at 60o on one face of an equilateral prism of refractive index n and emerges from the opposite face making an angle θ with the normal (see the figure). For n=√3 the value of θ is 60o and dθdn=m. The value of m is
Answer» A monochromatic beam of light is incident at $60^{o}$ on one face of an equilateral prism of refractive index $n$ and emerges from the opposite face making an angle $θ$ with the normal (see the figure). For $n = \sqrt{3}$ the value of $θ$ is $60^{o}$ and $\frac{d θ}{d n} = m$ . The value of $m$ is

Discussion

40.	A convex mirror of focal length f forms an image which is 1/ntimes the object. The distance of the object from the mirror is
Answer» A convex mirror of focal length f forms an image which is 1/ntimes the object. The distance of the object from the mirror is

Discussion

41.	Two forces are such that the sum of their magnitudes is 18 N and their resultant is perpendicular to the smaller force and magnitude of resultant is 12 N. Then the magnitudes of the forces are
Answer» Two forces are such that the sum of their magnitudes is 18 N and their resultant is perpendicular to the smaller force and magnitude of resultant is 12 N. Then the magnitudes of the forces are

Discussion

42.	The polarizing angle for a piece of glass for green light is 60∘. Find the angle of minimum deviation for green light for its passage through 60∘ prism, made of same glass.
Answer» The polarizing angle for a piece of glass for green light is $60^{\circ}$ . Find the angle of minimum deviation for green light for its passage through $60^{\circ}$ prism, made of same glass.

Discussion

43.	A 5kg block is tied to a 1m string and is rotated with a constant angular velocity of 2 rad/sec in the horizontal plane. Find the linear momentum of the block.
Answer» A 5kg block is tied to a 1m string and is rotated with a constant angular velocity of 2 rad/sec in the horizontal plane. Find the linear momentum of the block.

Discussion

44.	Hydrogen (H), deuterium (D), singly ionized helium (He+) and doubly ionized lithium (Li++) all have one electron around the nucleus. Consider n = 2 to n = 1 transition. The wavelengths of emitted radiations are λ1,λ2,λ3 and λ4 respectively. Then approximately
Answer» Hydrogen (H), deuterium (D), singly ionized helium $(H e^{+})$ and doubly ionized lithium $(L i^{+ +})$ all have one electron around the nucleus. Consider n = 2 to n = 1 transition. The wavelengths of emitted radiations are $λ_{1}, λ_{2}, λ_{3}$ and $λ_{4}$ respectively. Then approximately

Discussion

45.	A slender uniform rod of mass M and length l is pivoted at one end so that it can rotate in a vertical pane (see figure). There is negligible friction at the pivot. The free end is held vertically above the pivot and then released. The angular acceleration of the rod when it makes an angle θ with the vertical is
Answer» A slender uniform rod of mass $M$ and length $l$ is pivoted at one end so that it can rotate in a vertical pane (see figure). There is negligible friction at the pivot. The free end is held vertically above the pivot and then released. The angular acceleration of the rod when it makes an angle $θ$ with the vertical is

Discussion

46.	5 charges are placed in the corneres of a hexagon . what is the net force on a identical charge at cnetr
Answer» 5 charges are placed in the corneres of a hexagon . what is the net force on a identical charge at cnetr

Discussion

47.	Motion of a motorcyclist is shown in the figure. Which of the following shows the displacement-time graph for this motion?
Answer» Motion of a motorcyclist is shown in the figure. Which of the following shows the displacement-time graph for this motion?

Discussion

48.	How to represent displacement of a plane wave
Answer» How to represent displacement of a plane wave

Discussion

49.	Maximum value of f(x)=sinx+cosx is
Answer» Maximum value of $f (x) = sin x + cos x$ is

Discussion

50.	Position vector of a particle moving in x−y plane at time t is →r=a(1−cosωt)^i+asinωt^j and the angular velocity of the particle is ωo^k. The magnitude of the linear velocity of particle at t=π2ω is
Answer» Position vector of a particle moving in $x - y$ plane at time $t$ is $\to r = a (1 - cos ω t)^i + a sin ω t^j$ and the angular velocity of the particle is $ω_{o}^k$ . The magnitude of the linear velocity of particle at $t = \frac{π}{2 ω}$ is

Discussion

Explore topic-wise InterviewSolutions in Current Affairs.

Two thermally insulated vessels 1 and 2 are filled with air at temperatures (T1,T2), volume (V1,V2) and pressure (P1,P2) respectively. If the valve joining the two vessels is opened, the temperature inside the vessel at equilibrium will be

The time taken by a body to slide down a rough 45∘ inclined plane is thrice of that is required to slide down a smooth 45∘ inclined plane. The coefficient of kinetic friction between the object and rough plane is given by:

ntn ntQ. If R & H are the horizontal range and maximum height attained by a projectile, than its speed of projection isn nt1) 2gR + 4R2/gHn nt2) 2gH + R2g/8Hn nt3) 2gH + 8H/Rgn nt4) 2gH + R2/Hn

An ISLB 350 486 N/m beam is laterally supported throughout. The following properties are given for the I - sectionIx=13158.3×104mm4, shape factor =1.12,fy=250MPa,γmo=1.1Assume the section to be a compact section and a case of low shear. The design bending strength will be kNm.191.39

A second's pendulum is placed in a spacelaboratory orbiting around the earth at a height of3R, where R is the radius of earth. The time periodof the pendulum is

A car of mass m is accelerated on a plane road under the influence of a force in such a way that its velocity becomes v2 from v1 in a distance s. If a constant power P is generated by the car engine, then the velocity v2 will be

a ball of mass m is thrown upward and another ball ofsame mass is thrown downward so as to move freely under gravity . The acceleration of centre of mass is

An atom has weight of 7×10−9 lb. What will be the weight of 106atoms?

nttwo charged capacitor have their outer plates fixed and inner plates connected by a spring of force constant k. the charge on each capacitor is q. find the extension in the string at equilibrium?n

The given figure shows a set of equipotential surfaces. Find the magnitude and direction of electric field that exists in the region.

Two similar 400 V, 3-phase alternators share equal kW power delivered to a balanced three phase, 50 kW, 0.8 p.f. lagging load. If the power factor of one machine is 0.9 lag, then the current supplied by other machine is _____A.51.47

Cube of side ‘a’. Find net force on one of the charges due to the presence of ether charges.

A steel wire having a radius of 2.0 mm, carrying a load of 4 kg, is hanging from a ceiling. Given that g=3.1π ms−2, what will be the tensile stress that would be developed in the wire?

Three identical bulbs are connected as shown in figure. When switch S is open, the power consumed in bulb B is P. What will be the power consumed by the same bulb when switch S is closed?

Magnetic flux linked with inductor increase from 0 to x and current in inductor increase from 0 to y magnetic energy stored in inductor is.

A simple harmonic wave of amplitude 2 units is travelling along x - axis. At a given instant, displacements for two different particles on the wave are 1 unit and √2 units. If the wavelength of wave is λ, find the distance between them.

A boy standing on a long railroad car throws a ball straight upwards. The car is moving on the horizontal road with an acceleration of 1 m/s2 and the projection speed in the vertical direction is 9.8 m/s. How far behind the boy will the ball fall on the car?

the work functionof a surface of a photosensitive material is 6.2eV. The wavelength of the incident radiationfor which the stopping potential is 5

A particle of mass M at rest decays into two particles of masses m1 and m2, having non-zero velocities. The ratio of the de-Broglie wavelengths of the particles, λ1λ2 is

Derive the equation of motion in algebraic method?

An Am signal is modulated by 50% such that FOM of AM. becomes equal to the Figure of ment (FOM) of FM signal is FM modulated. The modulation index of FM will be _________0.272

Two electric dipole of moment p and 64p are placed in opposite directions on a line at a distance of 25 cm. The electric field will be zero at point between the dipoles whose distance from the dipole of moment p is

If a particle is projected at t=0 from ground with speed u= 20 m/s at an angle of 45^° from horizontal then find the ratio of time of flight to the time interval in which velocity of particle becomes perpendicular to initial velocity of projection -

Kirchhoff’s junction law is a consequence of which of the following law(s)?

Work done in increasing the size of a soap bubble from a radius of 3 cm to 5 cm is nearly (surface tension of soap solution = 0.03 Nm-1

A point charge Q is located at the centre of a cube of edge length a. The total electric flux through one of the face of the cube is

A particle of mass 2kg moves with an initial velocity u=(4i+4j)m/s.A constant force of F=-20j N is applied on the particle. Initially the particle was at (0,0). The x-coordinate of the particle when its y coordinate again becomes zero is given by

The number density of free electrons in a copper conductorestimated in Example 3.1 is 8.5 × 1028 m–3. How long does an electrontake to drift from one end of a wire 3.0 m long to its other end? Thearea of cross-section of the wire is 2.0 × 10–6 m2 and it is carrying acurrent of 3.0 A.

An electric dipole of moment P is released in a uniform electric field E from the position of maximum torque. Angular velocity of the dipole when P becomes parallel to E will be (I= moment of inertia of dipole) A) √2PE/IB) √PE/IC) √4PE/ID) √2I/PE

In wavy curve method from which side we shall start drawing the wave (upward or downeard side)?

To which part of the electromagnetic spectrum does a wave of frequency 5×1019 Hz belong?

A 100 W resistor is connected to a 220 V, 50 Hz ac supply. (a) What is the rms value of current in the circuit? (b) What is the net power consumed over a full cycle?

35.A man of mass M stands on a platform of mass m and pulls himself up by pulley arrangement shown in the figure. If he pulls each rope with force F determine the upward acceleration

When a beam of 10.6 eV photons of intensity falls on a platinum surface of area 1.0×10−4 m2 and work function 5.6 eV. If 53% of the incident photon eject photoelectrons. Total photoelectrons emitting per second is n×1011. Find n(integer only)

A monochromatic beam of light is incident at 60o on one face of an equilateral prism of refractive index n and emerges from the opposite face making an angle θ with the normal (see the figure). For n=√3 the value of θ is 60o and dθdn=m. The value of m is

A convex mirror of focal length f forms an image which is 1/ntimes the object. The distance of the object from the mirror is

Two forces are such that the sum of their magnitudes is 18 N and their resultant is perpendicular to the smaller force and magnitude of resultant is 12 N. Then the magnitudes of the forces are

The polarizing angle for a piece of glass for green light is 60∘. Find the angle of minimum deviation for green light for its passage through 60∘ prism, made of same glass.

A 5kg block is tied to a 1m string and is rotated with a constant angular velocity of 2 rad/sec in the horizontal plane. Find the linear momentum of the block.

Hydrogen (H), deuterium (D), singly ionized helium (He+) and doubly ionized lithium (Li++) all have one electron around the nucleus. Consider n = 2 to n = 1 transition. The wavelengths of emitted radiations are λ1,λ2,λ3 and λ4 respectively. Then approximately

5 charges are placed in the corneres of a hexagon . what is the net force on a identical charge at cnetr

Motion of a motorcyclist is shown in the figure. Which of the following shows the displacement-time graph for this motion?

How to represent displacement of a plane wave

Maximum value of f(x)=sinx+cosx is

Position vector of a particle moving in x−y plane at time t is →r=a(1−cosωt)^i+asinωt^j and the angular velocity of the particle is ωo^k. The magnitude of the linear velocity of particle at t=π2ω is