50278 + Interview Questions in Physics

1.	Two amplifiers are connected one after the other in series (cascaded).The first amplifier has a voltage gain of 10 and the second has avoltage gain of 20. If the input signal is 0.01 volt, calculate the outputac signal.
Answer» Two amplifiers are connected one after the other in series (cascaded).The first amplifier has a voltage gain of 10 and the second has avoltage gain of 20. If the input signal is 0.01 volt, calculate the outputac signal.

Discussion

2.	The volume of 1 mole of an ideal gas at STP (STP = 273.15 K and 1 bar) is X.7 L. The value of X is
Answer» The volume of $1 m o l e$ of an ideal gas at STP (STP = 273.15 K and 1 bar) is X.7 L. The value of X is

Discussion

3.	58.The meter bridge circuit shown in figure in balanced when jockey J divides wire AB into two parts AJ and BJ in the ratio 1:2. Then unknown resistance Q is:-
Answer» 58.The meter bridge circuit shown in figure in balanced when jockey J divides wire AB into two parts AJ and BJ in the ratio 1:2. Then unknown resistance Q is:-

Discussion

4.	There are 2 concentric spherical conducting shells of radii r and 3r. The outer shell carries a charge q and inner shell is uncharged. Inner shell is now connected with earth find the amount of charge flow from inner shell to the earth.
Answer» There are 2 concentric spherical conducting shells of radii r and 3r. The outer shell carries a charge q and inner shell is uncharged. Inner shell is now connected with earth find the amount of charge flow from inner shell to the earth.

Discussion

5.	In the following circuit the potential difference between the points B and C is balanced against 40 cm length of potentiometer wire. In order to balance the potential difference between the points C and D, where should jockey be pressed
Answer» In the following circuit the potential difference between the points B and C is balanced against 40 cm length of potentiometer wire. In order to balance the potential difference between the points C and D, where should jockey be pressed

Discussion

6.	why focal length of fluid decrease when it is imaresed in liquid
Answer» why focal length of fluid decrease when it is imaresed in liquid

Discussion

7.	AB is a resistanceless conducting rod which forms a diameter of a conducting ring of radius r rotating in a uniform magnetic field B as shown in the figure. The resistance R1 and R2 do not rotate. Then current through the resistor R1 is -
Answer» $A B$ is a resistanceless conducting rod which forms a diameter of a conducting ring of radius $r$ rotating in a uniform magnetic field $B$ as shown in the figure. The resistance $R_{1}$ and $R_{2}$ do not rotate. Then current through the resistor $R_{1}$ is -

Discussion

8.	A person was moving at a uniform speed, but suddenly he comes to rest. What will be his acceleration at rest?
Answer» A person was moving at a uniform speed, but suddenly he comes to rest. What will be his acceleration at rest?

Discussion

9.	KE of a body is increased by 44%. What is thepercent increase in the momentum?
Answer» KE of a body is increased by 44%. What is thepercent increase in the momentum?

Discussion

10.	A uniform electric field exists in space. No work is required to be done to move a charge on the line y=x. Which of the following may represent the direction of electric field?
Answer» A uniform electric field exists in space. No work is required to be done to move a charge on the line $y = x$ . Which of the following may represent the direction of electric field?

Discussion

11.	Starting at temperature 300 K, one mole of an ideal diatomic gas (γ=1.4) is first compressed adiabatically from volume V1 to V2=V116. It is then allowed to expand isobarically to volume 2V2. If all the processes are the quasi-static, then the final temperature of the gas (in K) is (to the nearest integer)
Answer» Starting at temperature $300 K$ , one mole of an ideal diatomic gas $(γ = 1.4)$ is first compressed adiabatically from volume $V_{1}$ to $V_{2} = \frac{V_{1}}{16}$ . It is then allowed to expand isobarically to volume $2 V_{2}$ . If all the processes are the quasi-static, then the final temperature of the gas (in $K$ ) is (to the nearest integer)

Discussion

12.	Moment of inertia of a uniform cylinder of mass M and radius R about its geometric axis is
Answer» Moment of inertia of a uniform cylinder of mass M and radius R about its geometric axis is

Discussion

13.	3.A particle is projected from ground with velocity 20root2 m/s at 45 degree. Prove that at time(s) 1 &3 s is at height 15 m from ground.
Answer» 3.A particle is projected from ground with velocity 20root2 m/s at 45 degree. Prove that at time(s) 1 &3 s is at height 15 m from ground.

Discussion

14.	A block of mass m rest on a horizontal floor with which it has a coefficient of static friction mue. For the block to just move
Answer» A block of mass m rest on a horizontal floor with which it has a coefficient of static friction mue. For the block to just move

Discussion

15.	A proton of mass 1.6×10−27 kg goes round in a circular orbit of radius 0.10 m under a centripetal force of 4×10−13N. then the frequency of revolution of the proton is about
Answer» A proton of mass $1.6 \times 10^{- 27}$ kg goes round in a circular orbit of radius 0.10 m under a centripetal force of $4 \times 10^{- 13} N$ . then the frequency of revolution of the proton is about

Discussion

16.	The equivalent inductance of the network shown in the figure, between the points a and b is -
Answer» The equivalent inductance of the network shown in the figure, between the points $a$ and $b$ is -

Discussion

17.	If Coulomb's law involved dependence of 1/r^{-3} instead of 1/r^{-2} where r is distance between two point changes would Gauss's law still be true?
Answer» If Coulomb's law involved dependence of 1/r^{-3} instead of 1/r^{-2} where r is distance between two point changes would Gauss's law still be true?

Discussion

18.	A long, straight wire, of radius a, carries a current distributed uniformly over its cross-section. The ratio of the magnetic fields due to the wire, at distances a3 and 2a, respectively from the axis of the wire, is:
Answer» A long, straight wire, of radius $a$ , carries a current distributed uniformly over its cross-section. The ratio of the magnetic fields due to the wire, at distances $\frac{a}{3} and 2 a,$ respectively from the axis of the wire, is:

Discussion

19.	A vessel of volume V contains an ideal gas at absolute temperature T and pressure P. The gas is allowed to leak till its pressure falls to P. Assuming that the temperature remains constant during leakage, the number of moles of the gas that have leaked is
Answer» A vessel of volume $V$ contains an ideal gas at absolute temperature $T$ and pressure $P$ . The gas is allowed to leak till its pressure falls to $P$ . Assuming that the temperature remains constant during leakage, the number of moles of the gas that have leaked is

Discussion

20.	The displacement equation for a particle in standing wave is represented as y(x,t)=0.4sin(0.5x)cos(30t), where x and y are in centimeter and time t is in seconds. Magnitude of velocity of particle at x=2.4 cm and t=0.8 s is -[ sin(1.2)=0.93,sin (24)=−0.9 ]
Answer» The displacement equation for a particle in standing wave is represented as $y (x, t) = 0.4 sin (0.5 x) cos (30 t)$ , where $x$ and $y$ are in $centimeter$ and time $t$ is in $seconds$ . Magnitude of velocity of particle at $x = 2.4 cm$ and $t = 0.8 s$ is - $[sin (1.2) = 0.93, sin (24) = - 0.9]$

Discussion

21.	A particle executes SHM with frequency f. Find frequency with which its kinetic energy oscillates
Answer» A particle executes SHM with frequency f. Find frequency with which its kinetic energy oscillates

Discussion

22.	Evaluate ∫(x3−ex+cosx)dx
Answer» Evaluate $\int (x^{3} - e^{x} + cos x) d x$

Discussion

23.	A moving coil galvanometer has resistance 50 Ω and it indicates full deflection at 4 mA current. A voltmeter is made using this galvanometer and a 5 k Ω resistance. The maximum voltage, that can be measured using this voltmeter will be close to
Answer» A moving coil galvanometer has resistance $50 Ω$ and it indicates full deflection at $4 mA$ current. A voltmeter is made using this galvanometer and a $5 k Ω$ resistance. The maximum voltage, that can be measured using this voltmeter will be close to

Discussion

24.	A source emits light of wavelengths 555 nm and 600 nm. The radiant flux of the 555 nm part is 40 W and of the 600 nm part is 30 W.The relative luminosity at 600 nm is 0.6 . Find (a) the total radiant flux, (b) the total luminous flux, (c) the luminous efficiency.
Answer» A source emits light of wavelengths 555 nm and 600 nm. The radiant flux of the 555 nm part is 40 W and of the 600 nm part is 30 W.The relative luminosity at 600 nm is 0.6 . Find (a) the total radiant flux, (b) the total luminous flux, (c) the luminous efficiency.

Discussion

25.	The sunlight reaching the earth has maximum electric field of 810 V/m. What is the maximum magnetic field in this light?
Answer» The sunlight reaching the earth has maximum electric field of $810 V / m$ . What is the maximum magnetic field in this light?

Discussion

26.	A sample contains only hydrogen atoms and in all atom electron are present at 4th excited state. How many minimum number of atoms are required if total 7 lines are observed in the emission spectrum
Answer» A sample contains only hydrogen atoms and in all atom electron are present at 4th excited state. How many minimum number of atoms are required if total 7 lines are observed in the emission spectrum

Discussion

27.	A horizontal force, just sufficient to move a body of mass 4 kg lying on a rough horizontal surface, is applied on it. The coefficient of static and kinetic friction between the body and the surface are 0.8 and 0.6, respectively. If the force continues to act even after the block has started moving, the acceleration of the block in m/s2 is (g=10 m/s2)
Answer» A horizontal force, just sufficient to move a body of mass $4 kg$ lying on a rough horizontal surface, is applied on it. The coefficient of static and kinetic friction between the body and the surface are 0.8 and 0.6, respectively. If the force continues to act even after the block has started moving, the acceleration of the block in ${m/s}^{2}$ is $(g = 10 {m/s}^{2})$

Discussion

28.	To find the distance d over which a signal canbe seen clearly in foggy conditions, a railwaysengineer uses dimensional analysis andassumes that the distance depends on themass density p of the fog, intensity (power/area) S of the light from the signal and itsfrequency f. The engineer finds that d isproportional to Sn The value of n is
Answer» To find the distance d over which a signal canbe seen clearly in foggy conditions, a railwaysengineer uses dimensional analysis andassumes that the distance depends on themass density p of the fog, intensity (power/area) S of the light from the signal and itsfrequency f. The engineer finds that d isproportional to Sn The value of n is

Discussion

29.	A tuning fork A produces 4 beats/sec with another tuning fork B of frequency 320HZ on filling one of the prongs of A 4beats/sec are again heard when sounded with the same fork B. Then the frequency of fork A before filing is a)328Hz b)316Hz
Answer» A tuning fork A produces 4 beats/sec with another tuning fork B of frequency 320HZ on filling one of the prongs of A 4beats/sec are again heard when sounded with the same fork B. Then the frequency of fork A before filing is a)328Hz b)316Hz

Discussion

30.	A wire shown in the figure is moving with a velocity of 10 m/s in the magnetic field of magnitude 0.3 T. If the distance between the points A and B is 15 cm. Calculate the emf induced between points A and B.
Answer» A wire shown in the figure is moving with a velocity of $10 m/s$ in the magnetic field of magnitude $0.3 T$ . If the distance between the points $A$ and $B$ is $15 cm$ . Calculate the emf induced between points $A$ and $B$ .

Discussion

31.	In the given figure the magnetix flux through the loop increases according to the relation ϕB(t)=10t2+20t, where ϕB is in milliwebers and t is in seconds.The magnitude of current through R=2 Ω resistor at t=5 s is (in mA)
Answer» In the given figure the magnetix flux through the loop increases according to the relation $ϕ_{B} (t) = 10 t^{2} + 20 t$ , where $ϕ_{B}$ is in milliwebers and $t$ is in seconds. The magnitude of current through $R = 2 Ω$ resistor at $t = 5 s$ is $(in mA)$

Discussion

32.	In the given circuit of potentiometer, the potential difference E across AB (10 m length) is larger than E1 and E2 as well. For key K1 (closed), the jockey is adjusted to touch the wire at point J1, so, that there is no deflection in the galvanometer. Now, the first battery (E1) is replaced by the second battery (E2) for working by making K1 open and K2 closed. The galvanometer then gives null deflection at J2. The value of E1E2 is ab, where, a=_____.
Answer» In the given circuit of potentiometer, the potential difference $E$ across $A B$ $(10 m$ length $)$ is larger than $E_{1}$ and $E_{2}$ as well. For key $K_{1}$ $($ closed $)$ , the jockey is adjusted to touch the wire at point $J_{1}$ , so, that there is no deflection in the galvanometer. Now, the first battery $(E_{1})$ is replaced by the second battery $(E_{2})$ for working by making $K_{1}$ open and $K_{2}$ closed. The galvanometer then gives null deflection at $J_{2}$ . The value of $\frac{E_{1}}{E_{2}}$ is $\frac{a}{b}$ , where, $a =$ _____.

Discussion

33.	An 8-pole, 200 V shunt excited dc generator has a lap wound armature having 100 coils of 8 turns. The resistance of each conductor is 0.025 Ω and field winding resistance is 100 Ω. If total core and mechanical losses are 1250 W. The current at maximum efficiency is _________51.38
Answer» An 8-pole, 200 V shunt excited dc generator has a lap wound armature having 100 coils of 8 turns. The resistance of each conductor is 0.025 $Ω$ and field winding resistance is 100 $Ω$ . If total core and mechanical losses are 1250 W. The current at maximum efficiency is _________ 51.38

Discussion

34.	What is Ori? How does it work?
Answer» What is Ori? How does it work?

Discussion

35.	In the Bohr's model of hydrogen atom, if atomic radius of the first orbit is x then the radius of the 3rd orbit will be??
Answer» In the Bohr's model of hydrogen atom, if atomic radius of the first orbit is x then the radius of the 3rd orbit will be??

Discussion

36.	Given is the pulley ,which is fixed to a ceiling having a block of mass 5kg on one side. Another side there is a another pulley. This pulley has other two blocks of different masses 2kg and 3.1 kg respectively. If given the acceleration of the first block ( of mass 5kg) is 1 metre per second square then what will be the acceleration of the block of mass 2kg?
Answer» Given is the pulley ,which is fixed to a ceiling having a block of mass 5kg on one side. Another side there is a another pulley. This pulley has other two blocks of different masses 2kg and 3.1 kg respectively. If given the acceleration of the first block ( of mass 5kg) is 1 metre per second square then what will be the acceleration of the block of mass 2kg?

Discussion

37.	a disc of radius 2 m and mass 100 kg rolls on a horizontal floor.its centre of mass has speed of 20m/s.how much work is needed to stop it
Answer» a disc of radius 2 m and mass 100 kg rolls on a horizontal floor.its centre of mass has speed of 20m/s.how much work is needed to stop it

Discussion

38.	Find the tension T2 in the string for the figure shown, if the surface is frictionless. (g=10 m/s2)
Answer» Find the tension $T_{2}$ in the string for the figure shown, if the surface is frictionless. $(g = 10 m / s^{2})$

Discussion

39.	The metallic bob of a simple pendulum has the relative density ρ. The time period of this pendulum is T. If the metallic bob is immersed in water, then the new time period is given by
Answer» The metallic bob of a simple pendulum has the relative density $ρ$ . The time period of this pendulum is $T$ . If the metallic bob is immersed in water, then the new time period is given by

Discussion

40.	The figure shows a cross -section of along thin ribbon of width b that is carrying a uniformly disturbed total current i into the page. Calculate the magnitude and direction of the magnetic field →B at a point P in the plane of the ribbon at a distance afrom its edge.
Answer» The figure shows a cross -section of along thin ribbon of width b that is carrying a uniformly disturbed total current i into the page. Calculate the magnitude and direction of the magnetic field $\to B$ at a point P in the plane of the ribbon at a distance afrom its edge.

40.

The figure shows a cross -section of along thin ribbon of width b that is carrying a uniformly disturbed total current i into the page. Calculate the magnitude and direction of the magnetic field →B at a point P in the plane of the ribbon at a distance afrom its edge.

Answer»

The figure shows a cross -section of along thin ribbon of width b that is carrying a uniformly disturbed total current i into the page. Calculate the magnitude and direction of the magnetic field $\to B$ at a point P in the plane of the ribbon at a distance afrom its edge.

Discussion

41.	A linear charge having linear charge density λ, penetrates a cube diagonally and it penetrates a sphere diametrically as shown below. What will be the ratio of flux coming out of the cube and the sphere?
Answer» A linear charge having linear charge density $λ$ , penetrates a cube diagonally and it penetrates a sphere diametrically as shown below. What will be the ratio of flux coming out of the cube and the sphere?

Discussion

42.	The time constant of a first order instrument having an inductance L and resistance R is equal to and is also equal to the time taken to indicate percent of step input.
Answer» The time constant of a first order instrument having an inductance L and resistance R is equal to and is also equal to the time taken to indicate percent of step input.

Discussion

43.	The angular width of the central maximum in a single sit diffraction pattern is 60∘. The width of the slit is 1 μm. The slit is illuminated by monochromatic plane waves. If another slit of same width is made near it, Young's fringes can be observed on a screen placed at a distance 50 cm from the silts. If the observed fringe width is 1 cm, what is slit separation distance? (i.e. distance between the centres of each slit)
Answer» The angular width of the central maximum in a single sit 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 same width is made near it, Young's fringes can be observed on a screen placed at a distance $50 c m$ from the silts. If the observed fringe width is $1 c m,$ what is slit separation distance? (i.e. distance between the centres of each slit)

Discussion

44.	Electrons are accelerated by voltage V0, initially electrons were at rest, speed after covering distance x is
Answer» Electrons are accelerated by voltage $V_{0},$ initially electrons were at rest, speed after covering distance x is

Discussion

45.	The inductive reactance of a coil is 1000Ω. If its self inductance and frequency both are increased two times then inductive reactance will be
Answer» The inductive reactance of a coil is $1000 Ω$ . If its self inductance and frequency both are increased two times then inductive reactance will be

Discussion

46.	A charged particle of mass m and charge q is projected towards a fixed charged particle of charge 3q along the line joining them,with a speed v from a very large dis†an ce .What is the minimum seperation attained between particles?
Answer» A charged particle of mass m and charge q is projected towards a fixed charged particle of charge 3q along the line joining them,with a speed v from a very large dis†an ce .What is the minimum seperation attained between particles?

Discussion

47.	The least count of a stop watch is 0.2 s. The time of 20 oscillations of a pendulum is measured to be 25 s. The percentage error in the measurement of time will be: (correct answer + 1, wrong answer - 0.25)
Answer» The least count of a stop watch is $0.2 s$ . The time of 20 oscillations of a pendulum is measured to be $25 s$ . The percentage error in the measurement of time will be: (correct answer + 1, wrong answer - 0.25)

Discussion

48.	The oxygen molecule has a mass of 5.30 × 10¯²⁶ kg and a moment of inertia of 1.94×10-¯⁴⁶ kg m2 about an axis through its centre perpendicular to the lines joining the two atoms. Suppose the mean speed of such a molecule in a gas is 500 m/s and that its kinetic energy of rotation is two thirds of its kinetic energy of translation. Find the average angular velocity of the molecule.
Answer» The oxygen molecule has a mass of 5.30 × 10¯²⁶ kg and a moment of inertia of 1.94×10-¯⁴⁶ kg m2 about an axis through its centre perpendicular to the lines joining the two atoms. Suppose the mean speed of such a molecule in a gas is 500 m/s and that its kinetic energy of rotation is two thirds of its kinetic energy of translation. Find the average angular velocity of the molecule.

Discussion

49.	The potential difference between the surface of charged sphere (radius R) and at the distance 3R from the surface of a sphere is V. The electric field at the distance which is equal to radius R from the surface will be
Answer» The potential difference between the surface of charged sphere (radius $R$ ) and at the distance $3 R$ from the surface of a sphere is $V$ . The electric field at the distance which is equal to radius $R$ from the surface will be

Discussion

50.	If the speed of the earth’s rotation is increased such that the apparent weight at the equator is one third the initial value, then what will be the length of the day in this case? (Take radius of Earth =6.4×106 m and g=10 m/s2)
Answer» If the speed of the earth’s rotation is increased such that the apparent weight at the equator is one third the initial value, then what will be the length of the day in this case? (Take radius of Earth = $6.4 \times 10^{6} m and g = 10 {m/s}^{2}$ )

Discussion

Explore topic-wise InterviewSolutions in Current Affairs.

Two amplifiers are connected one after the other in series (cascaded).The first amplifier has a voltage gain of 10 and the second has avoltage gain of 20. If the input signal is 0.01 volt, calculate the outputac signal.

The volume of 1 mole of an ideal gas at STP (STP = 273.15 K and 1 bar) is X.7 L. The value of X is

58.The meter bridge circuit shown in figure in balanced when jockey J divides wire AB into two parts AJ and BJ in the ratio 1:2. Then unknown resistance Q is:-

There are 2 concentric spherical conducting shells of radii r and 3r. The outer shell carries a charge q and inner shell is uncharged. Inner shell is now connected with earth find the amount of charge flow from inner shell to the earth.

In the following circuit the potential difference between the points B and C is balanced against 40 cm length of potentiometer wire. In order to balance the potential difference between the points C and D, where should jockey be pressed

why focal length of fluid decrease when it is imaresed in liquid

AB is a resistanceless conducting rod which forms a diameter of a conducting ring of radius r rotating in a uniform magnetic field B as shown in the figure. The resistance R1 and R2 do not rotate. Then current through the resistor R1 is -

A person was moving at a uniform speed, but suddenly he comes to rest. What will be his acceleration at rest?

KE of a body is increased by 44%. What is thepercent increase in the momentum?

A uniform electric field exists in space. No work is required to be done to move a charge on the line y=x. Which of the following may represent the direction of electric field?

Moment of inertia of a uniform cylinder of mass M and radius R about its geometric axis is

3.A particle is projected from ground with velocity 20root2 m/s at 45 degree. Prove that at time(s) 1 &3 s is at height 15 m from ground.

A block of mass m rest on a horizontal floor with which it has a coefficient of static friction mue. For the block to just move

A proton of mass 1.6×10−27 kg goes round in a circular orbit of radius 0.10 m under a centripetal force of 4×10−13N. then the frequency of revolution of the proton is about

The equivalent inductance of the network shown in the figure, between the points a and b is -

If Coulomb's law involved dependence of 1/r^{-3} instead of 1/r^{-2} where r is distance between two point changes would Gauss's law still be true?

A long, straight wire, of radius a, carries a current distributed uniformly over its cross-section. The ratio of the magnetic fields due to the wire, at distances a3 and 2a, respectively from the axis of the wire, is:

A vessel of volume V contains an ideal gas at absolute temperature T and pressure P. The gas is allowed to leak till its pressure falls to P. Assuming that the temperature remains constant during leakage, the number of moles of the gas that have leaked is

The displacement equation for a particle in standing wave is represented as y(x,t)=0.4sin(0.5x)cos(30t), where x and y are in centimeter and time t is in seconds. Magnitude of velocity of particle at x=2.4 cm and t=0.8 s is -[ sin(1.2)=0.93,sin (24)=−0.9 ]

A particle executes SHM with frequency f. Find frequency with which its kinetic energy oscillates

Evaluate ∫(x3−ex+cosx)dx

A moving coil galvanometer has resistance 50 Ω and it indicates full deflection at 4 mA current. A voltmeter is made using this galvanometer and a 5 k Ω resistance. The maximum voltage, that can be measured using this voltmeter will be close to

A source emits light of wavelengths 555 nm and 600 nm. The radiant flux of the 555 nm part is 40 W and of the 600 nm part is 30 W.The relative luminosity at 600 nm is 0.6 . Find (a) the total radiant flux, (b) the total luminous flux, (c) the luminous efficiency.

The sunlight reaching the earth has maximum electric field of 810 V/m. What is the maximum magnetic field in this light?

A sample contains only hydrogen atoms and in all atom electron are present at 4th excited state. How many minimum number of atoms are required if total 7 lines are observed in the emission spectrum

A tuning fork A produces 4 beats/sec with another tuning fork B of frequency 320HZ on filling one of the prongs of A 4beats/sec are again heard when sounded with the same fork B. Then the frequency of fork A before filing is a)328Hz b)316Hz

A wire shown in the figure is moving with a velocity of 10 m/s in the magnetic field of magnitude 0.3 T. If the distance between the points A and B is 15 cm. Calculate the emf induced between points A and B.

In the given figure the magnetix flux through the loop increases according to the relation ϕB(t)=10t2+20t, where ϕB is in milliwebers and t is in seconds.The magnitude of current through R=2 Ω resistor at t=5 s is (in mA)

An 8-pole, 200 V shunt excited dc generator has a lap wound armature having 100 coils of 8 turns. The resistance of each conductor is 0.025 Ω and field winding resistance is 100 Ω. If total core and mechanical losses are 1250 W. The current at maximum efficiency is _________51.38

What is Ori? How does it work?

In the Bohr's model of hydrogen atom, if atomic radius of the first orbit is x then the radius of the 3rd orbit will be??

a disc of radius 2 m and mass 100 kg rolls on a horizontal floor.its centre of mass has speed of 20m/s.how much work is needed to stop it

Find the tension T2 in the string for the figure shown, if the surface is frictionless. (g=10 m/s2)

The metallic bob of a simple pendulum has the relative density ρ. The time period of this pendulum is T. If the metallic bob is immersed in water, then the new time period is given by

The figure shows a cross -section of along thin ribbon of width b that is carrying a uniformly disturbed total current i into the page. Calculate the magnitude and direction of the magnetic field →B at a point P in the plane of the ribbon at a distance afrom its edge.

A linear charge having linear charge density λ, penetrates a cube diagonally and it penetrates a sphere diametrically as shown below. What will be the ratio of flux coming out of the cube and the sphere?

The time constant of a first order instrument having an inductance L and resistance R is equal to and is also equal to the time taken to indicate percent of step input.

Electrons are accelerated by voltage V0, initially electrons were at rest, speed after covering distance x is

The inductive reactance of a coil is 1000Ω. If its self inductance and frequency both are increased two times then inductive reactance will be

A charged particle of mass m and charge q is projected towards a fixed charged particle of charge 3q along the line joining them,with a speed v from a very large dis†an ce .What is the minimum seperation attained between particles?

The least count of a stop watch is 0.2 s. The time of 20 oscillations of a pendulum is measured to be 25 s. The percentage error in the measurement of time will be: (correct answer + 1, wrong answer - 0.25)

The potential difference between the surface of charged sphere (radius R) and at the distance 3R from the surface of a sphere is V. The electric field at the distance which is equal to radius R from the surface will be

If the speed of the earth’s rotation is increased such that the apparent weight at the equator is one third the initial value, then what will be the length of the day in this case? (Take radius of Earth =6.4×106 m and g=10 m/s2)