50278 + Interview Questions in Physics

1.	A circular wire loop of radius R is placed in the x -y plane centered at the origin O . A square loop of side a(a
Answer» A circular wire loop of radius R is placed in the x -y plane centered at the origin O . A square loop of side a(a $z = \sqrt 3 R along the axis of the circular wire loop, as shown in figure. The plane of the square loop makes an angle of 45^{0} with respect to the z -axis. If the mutual inductance between the loops is given by \frac{μ_{0} a^{2}}{2^{\frac{P}{2}} R}, then the value of p is$

Discussion

2.	Circuit shown in figure is a simple ohm – meter, in which G is a galvanometer (of very small resistance compared to R and Ro ), Ro is a known resistance and R is the resistance which is to be measured. If A and B are short circuited by a resistance less wire, galvanometer gives full scale deflection. Then to read the resistance R directly from galvanometer, its scale would look like
Answer» Circuit shown in figure is a simple ohm – meter, in which G is a galvanometer (of very small resistance compared to R and $R_{o}$ ), $R_{o}$ is a known resistance and R is the resistance which is to be measured. If A and B are short circuited by a resistance less wire, galvanometer gives full scale deflection. Then to read the resistance R directly from galvanometer, its scale would look like

2.

Circuit shown in figure is a simple ohm – meter, in which G is a galvanometer (of very small resistance compared to R and Ro ), Ro is a known resistance and R is the resistance which is to be measured. If A and B are short circuited by a resistance less wire, galvanometer gives full scale deflection. Then to read the resistance R directly from galvanometer, its scale would look like

Answer»

Circuit shown in figure is a simple ohm – meter, in which G is a galvanometer (of very small resistance compared to R and $R_{o}$ ), $R_{o}$ is a known resistance and R is the resistance which is to be measured. If A and B are short circuited by a resistance less wire, galvanometer gives full scale deflection. Then to read the resistance R directly from galvanometer, its scale would look like

Discussion

3.	A block of mass m is attached rigidly to a spring of stiffness k1 & touches another spring of stiffness k2 as shown in the figure. Assuming the surface is smooth, the period of oscillation of the block is
Answer» A block of mass $m$ is attached rigidly to a spring of stiffness $k_{1}$ & touches another spring of stiffness $k_{2}$ as shown in the figure. Assuming the surface is smooth, the period of oscillation of the block is

Discussion

4.	A uniform metre scale of length 1 m is balanced on a fixed semi-circular cylinder of radius 30 cm as shown in figure. One end of the scale is slightly depressed and released. The time period (in seconds) of the resulting simple harmonic motion is (Take g=10 ms−2)
Answer» A uniform metre scale of length $1 m$ is balanced on a fixed semi-circular cylinder of radius $30 cm$ as shown in figure. One end of the scale is slightly depressed and released. The time period (in seconds) of the resulting simple harmonic motion is $(Take g = 10 {ms}^{- 2})$

Discussion

5.	A sphere of mass 10 kg is moving on a horizontal plane with a velocity (10^i+^j) m/s where it collides with a vertical wall which is parallel to ^j. If the coefficient of restitution is 0.5, find the impulse (in SI units) acted on the sphere.
Answer» A sphere of mass $10 kg$ is moving on a horizontal plane with a velocity $(10^i +^j) m/s$ where it collides with a vertical wall which is parallel to $^j$ . If the coefficient of restitution is $0.5$ , find the impulse (in SI units) acted on the sphere.

Discussion

6.	For which transition of He+ spectrum energy will be same as 2nd line of Balmer series of H spectrum?
Answer» For which transition of $H e^{+}$ spectrum energy will be same as $2^{n d}$ line of Balmer series of H spectrum?

Discussion

7.	A body travels half of its total path in the last second of its fall from rest. If t and H are the time and height of its fall (take g=10 m/s2). Then,
Answer» A body travels half of its total path in the last second of its fall from rest. If $t$ and $H$ are the time and height of its fall (take $g = 10 {m/s}^{2}$ ). Then,

Discussion

8.	A particle having charge q enters a region of uniform magnetic field →B (directed inwards) and is deflected a distance x after travelling a distance y. The magnitude of the momentum of the particle is
Answer» A particle having charge $q$ enters a region of uniform magnetic field $\to B$ (directed inwards) and is deflected a distance $x$ after travelling a distance $y$ . The magnitude of the momentum of the particle is

Discussion

9.	There is a small air bubble inside a thick lens of glass as shown in the figure. What is the distance between the images of the air bubble as seen by two observers, one in air and other in water? (Given radius of curved surface is 5 cm)
Answer» There is a small air bubble inside a thick lens of glass as shown in the figure. What is the distance between the images of the air bubble as seen by two observers, one in air and other in water? (Given radius of curved surface is 5 cm)

9.

There is a small air bubble inside a thick lens of glass as shown in the figure. What is the distance between the images of the air bubble as seen by two observers, one in air and other in water? (Given radius of curved surface is 5 cm)

Answer»

There is a small air bubble inside a thick lens of glass as shown in the figure. What is the distance between the images of the air bubble as seen by two observers, one in air and other in water?
(Given radius of curved surface is 5 cm)

Discussion

10.	Real image of real object is formed by a convex lens. If the distance between real object and its real image is 80 cm, then power of lens may be
Answer» Real image of real object is formed by a convex lens. If the distance between real object and its real image is $80 cm$ , then power of lens may be

Discussion

11.	A solid cylinder of radius R made of a material of thermal conductivity K1 is surrounded by a cylindrical shell of inner radius R and outer radius 2R made of a material of thermal conductivity K2. The two ends of the combined system are maintained at two different temperatures. If there is no loss of heat across the cylindrical surface and the system is in steady state, the effective thermal conductivity of the system is:
Answer» A solid cylinder of radius $R$ made of a material of thermal conductivity $K_{1}$ is surrounded by a cylindrical shell of inner radius $R$ and outer radius $2 R$ made of a material of thermal conductivity $K_{2} .$ The two ends of the combined system are maintained at two different temperatures. If there is no loss of heat across the cylindrical surface and the system is in steady state, the effective thermal conductivity of the system is:

Discussion

12.	A constant force F1=10√3N applied at an angle 30∘ with horizontal on body (m=5 kg) at rest for 8 second. In this time interval, body moves from position A to B. To move from position B to A, another constant force F2=20 N is applied on body . If work done by this force is 960 J, then find the angle at which the force is acting on the body with horizontal.
Answer» A constant force $F_{1} = 10 \sqrt{3} N$ applied at an angle $30^{\circ}$ with horizontal on body $(m = 5 kg)$ at rest for $8 second$ . In this time interval, body moves from position A to B. To move from position B to A, another constant force $F_{2} = 20 N$ is applied on body . If work done by this force is $960 J$ , then find the angle at which the force is acting on the body with horizontal.

Discussion

13.	An LPG cylinder [consider it to be perfectly cylindrical] of mass 15 kg containing 10 kg of LPG is performing pure rolling on horizontal surface at speed of 0.5 m/s. Kinetic energy (in J) of cylinder with gas is (Ignore the internal energy of the gas)
Answer» An LPG cylinder [consider it to be perfectly cylindrical] of mass 15 kg containing 10 kg of LPG is performing pure rolling on horizontal surface at speed of 0.5 m/s. Kinetic energy (in J) of cylinder with gas is (Ignore the internal energy of the gas)

Discussion

14.	A Kundt's tube apparatus has a steel rod of length it m clamped at the centre. It is vibrated in its fundamental mode at a frequency of 2600 Hz. The lycopodium powder dispersed in the tube collects into heaps separated by 6.5 cm. Calculate the speed of sound in steel and in air.
Answer» A Kundt's tube apparatus has a steel rod of length it m clamped at the centre. It is vibrated in its fundamental mode at a frequency of 2600 Hz. The lycopodium powder dispersed in the tube collects into heaps separated by 6.5 cm. Calculate the speed of sound in steel and in air.

Discussion

15.	A bob of mass ′m′ is attached to ceiling of a lift with the help of string as shown. Calculate tension in string when lift is accelerated up with acceleration ′a′.
Answer» A bob of mass $^{'} m^{'}$ is attached to ceiling of a lift with the help of string as shown. Calculate tension in string when lift is accelerated up with acceleration $^{'} a^{'}$ .

Discussion

16.	A system of 3 blocks of masses of 10 kg,20 kg,30 kg respectively, having flat surfaces of contact with coefficients of friction given in the figure are at rest initially. If a constant horizontal force of F=100 N is acting on 10 kg block as shown in figure, then the magnitude of acceleration of the 20 kg block with respect to the ground is (Take g=10 m/s2)
Answer» A system of 3 blocks of masses of $10 k g, 20 k g, 30 k g$ respectively, having flat surfaces of contact with coefficients of friction given in the figure are at rest initially. If a constant horizontal force of $F = 100 N$ is acting on $10 k g$ block as shown in figure, then the magnitude of acceleration of the $20 k g$ block with respect to the ground is (Take $g = 10 m / s^{2})$

Discussion

17.	In a given scale X, the ice point is 40 ∘C and the steam point is 120 ∘C. For another scale Y, the ice point and steam point are −30 ∘C and 130 ∘C respectively. If X reads 50 ∘C temperature of a body, then Y would read
Answer» In a given scale $X$ , the ice point is $40^{\circ} C$ and the steam point is $120^{\circ} C$ . For another scale $Y$ , the ice point and steam point are $- 30^{\circ} C$ and $130^{\circ} C$ respectively. If $X$ reads $50^{\circ} C$ temperature of a body, then $Y$ would read

Discussion

18.	A particle is projected from a horizontal plane (x-y plane) such that its velocity vector at time t is given by v=a^i+(b−ct)^j. Its range on the horizontal plane is given by
Answer» A particle is projected from a horizontal plane (x-y plane) such that its velocity vector at time t is given by $v = a^i + (b - c t)^j$ . Its range on the horizontal plane is given by

Discussion

19.	For a given photosensitive material and with a source of constant frequency of incident radiation, how does the photocurrent vary with the intensity of incident light?
Answer» For a given photosensitive material and with a source of constant frequency of incident radiation, how does the photocurrent vary with the intensity of incident light?

Discussion

20.	A solid sphere is rolling on a surface as shown in the figure with a translational velocity v. If it is to climb the inclined surface, then v should be
Answer» A solid sphere is rolling on a surface as shown in the figure with a translational velocity $v$ . If it is to climb the inclined surface, then $v$ should be

Discussion

21.	What is the true weight of an oboject in a geostationary satellite that eighed exactly 10.0 N at the north pole?
Answer» What is the true weight of an oboject in a geostationary satellite that eighed exactly 10.0 N at the north pole?

Discussion

22.	Given molecular weight of hydrogen molecule is M=2.016×10−3 kg/mol. Calculate the root - mean-square speed of hydrogen molecules (H2) in km/s at 373.15 K(100∘C). (Answer the nearest integer)
Answer» Given molecular weight of hydrogen molecule is $M = 2.016 \times 10^{- 3} kg/mol$ . Calculate the root - mean-square speed of hydrogen molecules $(H_{2})$ in km/s at $373.15 K (100^{\circ} C)$ . (Answer the nearest integer)

Discussion

23.	Boyle's, Charles' and Avogadro's results on the different state variables of a gas, can be combined into one "equation of state” known as the ideal gas equation, PV = nRT, where R = 8.514 J/mol-K. Consider the following situation. A mixture of hydrogen and oxygen has volume 2000 cm3, temperature 300 K, pressure 100 kPa and mass 0.76 gms. Calculate the masses of hydrogen and oxygen in the mixture.
Answer» Boyle's, Charles' and Avogadro's results on the different state variables of a gas, can be combined into one "equation of state” known as the ideal gas equation, PV = nRT, where R = 8.514 J/mol-K. Consider the following situation. A mixture of hydrogen and oxygen has volume $2000 c m^{3}$ , temperature 300 K, pressure 100 kPa and mass 0.76 gms. Calculate the masses of hydrogen and oxygen in the mixture.

23.

Boyle's, Charles' and Avogadro's results on the different state variables of a gas, can be combined into one "equation of state” known as the ideal gas equation, PV = nRT, where R = 8.514 J/mol-K. Consider the following situation. A mixture of hydrogen and oxygen has volume 2000 cm3, temperature 300 K, pressure 100 kPa and mass 0.76 gms. Calculate the masses of hydrogen and oxygen in the mixture.

Answer»

Boyle's, Charles' and Avogadro's results on the different state variables of a gas, can be combined into one "equation of state” known as the ideal gas equation, PV = nRT, where R = 8.514 J/mol-K. Consider the following situation.

A mixture of hydrogen and oxygen has volume $2000 c m^{3}$ , temperature 300 K, pressure 100 kPa and mass 0.76 gms. Calculate the masses of hydrogen and oxygen in the mixture.

Discussion

24.	Three particles of mass m1=1 kg, m2=2 kg, m3=3 kg are placed at the corners A,B,C of an equilateral triangle, respectively. The edge length of the triangle is 1 m. Find the distance of COM of the system of particles from corner A.
Answer» Three particles of mass $m_{1} = 1 kg$ , $m_{2} = 2 kg$ , $m_{3} = 3 kg$ are placed at the corners $A, B, C$ of an equilateral triangle, respectively. The edge length of the triangle is $1 m$ . Find the distance of $COM$ of the system of particles from corner $A$ .

Discussion

25.	why fluorine is more electro negative than hydrogen?
Answer» why fluorine is more electro negative than hydrogen?

Discussion

26.	If the speed of a car is given as v=3t2+2t+3 m/s, total distance covered by the car in 10 sec is
Answer» If the speed of a car is given as $v = 3 t^{2} + 2 t + 3 m/s$ , total distance covered by the car in $10 s e c$ is

Discussion

27.	the frequency of ac is doubled , what happens of a) Inductive reactance b)capacitive reactance with frequency of alternating frequency
Answer» the frequency of ac is doubled , what happens of a) Inductive reactance b)capacitive reactance with frequency of alternating frequency

Discussion

28.	Which of the following is a one dimensional motion
Answer» Which of the following is a one dimensional motion

Discussion

29.	The force F is given in terms of time t and displacement x by the equation F = A cos Bx + C sin Dt. The dimensional formula of DB is:
Answer» The force F is given in terms of time t and displacement x by the equation F = A cos Bx + C sin Dt. The dimensional formula of $\frac{D}{B}$ is:

Discussion

30.	In an L−R circuit connected to a battery of constant e.m.f E, switch S is closed at time t = 0. If e denotes the magnitude of induced e.m.f across inductor and i the current in the circuit at any time t. Then which of the following graphs shows the variation of e with i ?
Answer» In an $L - R$ circuit connected to a battery of constant e.m.f $E$ , switch S is closed at time t = 0. If e denotes the magnitude of induced e.m.f across inductor and i the current in the circuit at any time t. Then which of the following graphs shows the variation of $e$ with $i$ ?

Discussion

31.	We humans are not much harmed due to attractive or repulsive electrical force / shock cz we are conductors connected to the earth( earthing). What if two humans are charged in space . / they are given shock. What would happen ?
Answer» We humans are not much harmed due to attractive or repulsive electrical force / shock cz we are conductors connected to the earth( earthing). What if two humans are charged in space . / they are given shock. What would happen ?

Discussion

32.	A capacitor circuit is equipped with key switch k as shown. Initially key switch is open. The excess charge flowing through the cell on closing the key k is equal to
Answer» A capacitor circuit is equipped with key switch $k$ as shown. Initially key switch is open. The excess charge flowing through the cell on closing the key $k$ is equal to

Discussion

33.	The electric flux due to a dipole is zero.But,the field due to the dipole is not zero.How?
Answer» The electric flux due to a dipole is zero.But,the field due to the dipole is not zero.How?

Discussion

34.	Which of the following expression is equal to cosθ, where θ is angle between →A and →B?
Answer» Which of the following expression is equal to $cos θ$ , where $θ$ is angle between $\to A and \to B$ ?

Discussion

35.	If y=sinx and x=3t, then dydt will be
Answer» If $y = sin x$ and $x = 3 t$ , then $\frac{d y}{d t}$ will be

Discussion

36.	Explain why a) To keep a piece of paper horizontal, you should blow over, not under, it b) When we try to close a water tap with our fingers, fast jets of water gush through the openings between our fingers c) The size of the needle of a syringe controls flow rate better than the thumb pressure exerted by a doctor while administering an injection d) A fluid flowing out of a small hole in a vessel results in a backward thrust on the vessel e) A spinning cricket ball in air does not follow a parabolic trajectory
Answer» Explain why a) To keep a piece of paper horizontal, you should blow over, not under, it b) When we try to close a water tap with our fingers, fast jets of water gush through the openings between our fingers c) The size of the needle of a syringe controls flow rate better than the thumb pressure exerted by a doctor while administering an injection d) A fluid flowing out of a small hole in a vessel results in a backward thrust on the vessel e) A spinning cricket ball in air does not follow a parabolic trajectory

36.

Explain why a) To keep a piece of paper horizontal, you should blow over, not under, it b) When we try to close a water tap with our fingers, fast jets of water gush through the openings between our fingers c) The size of the needle of a syringe controls flow rate better than the thumb pressure exerted by a doctor while administering an injection d) A fluid flowing out of a small hole in a vessel results in a backward thrust on the vessel e) A spinning cricket ball in air does not follow a parabolic trajectory

Answer»

Explain why
a) To keep a piece of paper horizontal, you should blow over, not under, it

b) When we try to close a water tap with our fingers, fast jets of water gush through the openings between our fingers

c) The size of the needle of a syringe controls flow rate better than the thumb pressure exerted by a doctor while administering an injection

d) A fluid flowing out of a small hole in a vessel results in a backward thrust on the vessel

e) A spinning cricket ball in air does not follow a parabolic trajectory

Discussion

37.	A body of mass m is accelerated uniformly from rest to a speed v in time T. The instantaneous power delivered to the body as a function of time is given by
Answer» A body of mass m is accelerated uniformly from rest to a speed v in time T. The instantaneous power delivered to the body as a function of time is given by

Discussion

38.	Two tuning forks have frequencies 450 Hz and 454 Hz respectively. On sounding these forks together, the time interval between successive maximum intensities will be [MP PET 1989; MP PMT 2003]
Answer» Two tuning forks have frequencies 450 Hz and 454 Hz respectively. On sounding these forks together, the time interval between successive maximum intensities will be [MP PET 1989; MP PMT 2003]

38.

Two tuning forks have frequencies 450 Hz and 454 Hz respectively. On sounding these forks together, the time interval between successive maximum intensities will be [MP PET 1989; MP PMT 2003]

Answer»

Two tuning forks have frequencies 450 Hz and 454 Hz respectively. On

sounding these forks together, the time interval between successive

maximum intensities will be

[MP PET 1989; MP PMT 2003]

Discussion

39.	What is the refractive index of the material of a plano-convex lens, if the radius of curvature of the convex surface is 10 cm and focal length of the lens is 30 cm?
Answer» What is the refractive index of the material of a plano-convex lens, if the radius of curvature of the convex surface is $10 c m$ and focal length of the lens is $30 c m$ ?

Discussion

40.	A charge (q, m) is projected perpendicular away from an infinitely long wire carrying a current i with a speed v0. Find the maximum separation between the charge and the wire in the subsequent motion if the initial separation is x0.
Answer» A charge (q, m) is projected perpendicular away from an infinitely long wire carrying a current i with a speed $v_{0}$ . Find the maximum separation between the charge and the wire in the subsequent motion if the initial separation is $x_{0}$ .

Discussion

41.	The velocity of a particle moving along a straight line increases according to the linear law v = v0 + kx where k is a constant . Then 1) the accelearation of the particle is k(v0 + kx) 2) the particle takes a time 1k loge (v1v0) to attain a velocity v1 3) velocity varies linearly with displacement with slope of velocity displacement curve equal to k 4) data is insufficient to arrive at a conclusion.
Answer» The velocity of a particle moving along a straight line increases according to the linear law v = $v_{0}$ + kx where k is a constant . Then 1) the accelearation of the particle is k( $v_{0}$ + kx) 2) the particle takes a time $\frac{1}{k}$ $l o g_{e}$ ( $\frac{v_{1}}{v_{0}}$ ) to attain a velocity $v_{1}$ 3) velocity varies linearly with displacement with slope of velocity displacement curve equal to k 4) data is insufficient to arrive at a conclusion.

41.

The velocity of a particle moving along a straight line increases according to the linear law v = v0 + kx where k is a constant . Then 1) the accelearation of the particle is k(v0 + kx) 2) the particle takes a time 1k loge (v1v0) to attain a velocity v1 3) velocity varies linearly with displacement with slope of velocity displacement curve equal to k 4) data is insufficient to arrive at a conclusion.

Answer»

The velocity of a particle moving along a straight line increases according to the linear law v = $v_{0}$ + kx

where k is a constant . Then

1) the accelearation of the particle is k( $v_{0}$ + kx)

2) the particle takes a time $\frac{1}{k}$ $l o g_{e}$ ( $\frac{v_{1}}{v_{0}}$ ) to attain a velocity $v_{1}$

3) velocity varies linearly with displacement with slope of velocity displacement curve equal to k

4) data is insufficient to arrive at a conclusion.

Discussion

42.	What is the coefficient of performance?
Answer» What is the coefficient of performance?

Discussion

43.	A block A of mass 7 kg is placed on a frictionless table. A thread tied to it passes over a frictionless pulley and carries a body B of mass 3 kg at the other end. The acceleration of the system is (given g=10 ms−2)
Answer» A block A of mass 7 kg is placed on a frictionless table. A thread tied to it passes over a frictionless pulley and carries a body B of mass 3 kg at the other end. The acceleration of the system is (given $g = 10 m s^{- 2}$ )

Discussion

44.	A ball falls from a height of 1 m on the ground and jumps upto a height H. If the coefficient of restitution of the collision is 0.9, then find the value of H. (Take g=10 m/s2)
Answer» A ball falls from a height of $1 m$ on the ground and jumps upto a height $H$ . If the coefficient of restitution of the collision is $0.9$ , then find the value of $H$ . (Take $g = 10 m / s^{2}$ )

Discussion

45.	The capacity of each condenser in the following fig. is ‘C’. Then the equivalent capacitance across A and B is?
Answer» The capacity of each condenser in the following fig. is ‘C’. Then the equivalent capacitance across A and B is?

Discussion

46.	A wooden cube just floats inside water with a 400 gm mass placed on it. When the mass is removed, the cube floats with its top surface 4 cm above the water level. What is the side of the cube?
Answer» A wooden cube just floats inside water with a $400 gm$ mass placed on it. When the mass is removed, the cube floats with its top surface $4 cm$ above the water level. What is the side of the cube?

Discussion

47.	A simple pendulum is suspended from the ceiling of a car taking a turn of radius 10 m at a speed of 36 km/h. Find the angle made by the string of the pendulum with the vertical if this angle does not change during the turn. Take g = 10 m/s2.
Answer» A simple pendulum is suspended from the ceiling of a car taking a turn of radius 10 m at a speed of 36 km/h. Find the angle made by the string of the pendulum with the vertical if this angle does not change during the turn. Take g = $10 m / s^{2}$ .

Discussion

48.	A series LCR circuit containing a resistor of 120 Ω has an angular resonant frequency 4×105 rad s−1. At resonance the voltages across resistor and inductor are 60 V and 40V respectively. The value of capacitance C is
Answer» A series LCR circuit containing a resistor of $120 Ω$ has an angular resonant frequency $4 \times 10^{5} r a d s^{- 1}$ . At resonance the voltages across resistor and inductor are 60 V and $40 V$ respectively. The value of capacitance C is

Discussion

49.	A person's eye is at a height of 1.5m. He stands in front of a 0.3m long plane mirror whose lower end is 0.8m above the ground. The length of the image he sees himself is?
Answer» A person's eye is at a height of 1.5m. He stands in front of a 0.3m long plane mirror whose lower end is 0.8m above the ground. The length of the image he sees himself is?

Discussion

50.	What is the difference between electric potential and potential difference?
Answer» What is the difference between electric potential and potential difference?

Discussion

Explore topic-wise InterviewSolutions in Current Affairs.

A circular wire loop of radius R is placed in the x -y plane centered at the origin O . A square loop of side a(a

A block of mass m is attached rigidly to a spring of stiffness k1 &amp; touches another spring of stiffness k2 as shown in the figure. Assuming the surface is smooth, the period of oscillation of the block is

A uniform metre scale of length 1 m is balanced on a fixed semi-circular cylinder of radius 30 cm as shown in figure. One end of the scale is slightly depressed and released. The time period (in seconds) of the resulting simple harmonic motion is (Take g=10 ms−2)

A sphere of mass 10 kg is moving on a horizontal plane with a velocity (10^i+^j) m/s where it collides with a vertical wall which is parallel to ^j. If the coefficient of restitution is 0.5, find the impulse (in SI units) acted on the sphere.

For which transition of He+ spectrum energy will be same as 2nd line of Balmer series of H spectrum?

A body travels half of its total path in the last second of its fall from rest. If t and H are the time and height of its fall (take g=10 m/s2). Then,

A particle having charge q enters a region of uniform magnetic field →B (directed inwards) and is deflected a distance x after travelling a distance y. The magnitude of the momentum of the particle is

There is a small air bubble inside a thick lens of glass as shown in the figure. What is the distance between the images of the air bubble as seen by two observers, one in air and other in water? (Given radius of curved surface is 5 cm)

Real image of real object is formed by a convex lens. If the distance between real object and its real image is 80 cm, then power of lens may be

An LPG cylinder [consider it to be perfectly cylindrical] of mass 15 kg containing 10 kg of LPG is performing pure rolling on horizontal surface at speed of 0.5 m/s. Kinetic energy (in J) of cylinder with gas is (Ignore the internal energy of the gas)

A Kundt's tube apparatus has a steel rod of length it m clamped at the centre. It is vibrated in its fundamental mode at a frequency of 2600 Hz. The lycopodium powder dispersed in the tube collects into heaps separated by 6.5 cm. Calculate the speed of sound in steel and in air.

A bob of mass ′m′ is attached to ceiling of a lift with the help of string as shown. Calculate tension in string when lift is accelerated up with acceleration ′a′.

In a given scale X, the ice point is 40 ∘C and the steam point is 120 ∘C. For another scale Y, the ice point and steam point are −30 ∘C and 130 ∘C respectively. If X reads 50 ∘C temperature of a body, then Y would read

A particle is projected from a horizontal plane (x-y plane) such that its velocity vector at time t is given by v=a^i+(b−ct)^j. Its range on the horizontal plane is given by

For a given photosensitive material and with a source of constant frequency of incident radiation, how does the photocurrent vary with the intensity of incident light?

A solid sphere is rolling on a surface as shown in the figure with a translational velocity v. If it is to climb the inclined surface, then v should be

What is the true weight of an oboject in a geostationary satellite that eighed exactly 10.0 N at the north pole?

Given molecular weight of hydrogen molecule is M=2.016×10−3 kg/mol. Calculate the root - mean-square speed of hydrogen molecules (H2) in km/s at 373.15 K(100∘C). (Answer the nearest integer)

Three particles of mass m1=1 kg, m2=2 kg, m3=3 kg are placed at the corners A,B,C of an equilateral triangle, respectively. The edge length of the triangle is 1 m. Find the distance of COM of the system of particles from corner A.

why fluorine is more electro negative than hydrogen?

If the speed of a car is given as v=3t2+2t+3 m/s, total distance covered by the car in 10 sec is

the frequency of ac is doubled , what happens of a) Inductive reactance b)capacitive reactance with frequency of alternating frequency

Which of the following is a one dimensional motion

The force F is given in terms of time t and displacement x by the equation F = A cos Bx + C sin Dt. The dimensional formula of DB is:

In an L−R circuit connected to a battery of constant e.m.f E, switch S is closed at time t = 0. If e denotes the magnitude of induced e.m.f across inductor and i the current in the circuit at any time t. Then which of the following graphs shows the variation of e with i ?

We humans are not much harmed due to attractive or repulsive electrical force / shock cz we are conductors connected to the earth( earthing). What if two humans are charged in space . / they are given shock. What would happen ?

A capacitor circuit is equipped with key switch k as shown. Initially key switch is open. The excess charge flowing through the cell on closing the key k is equal to

The electric flux due to a dipole is zero.But,the field due to the dipole is not zero.How?

Which of the following expression is equal to cosθ, where θ is angle between →A and →B?

If y=sinx and x=3t, then dydt will be

A body of mass m is accelerated uniformly from rest to a speed v in time T. The instantaneous power delivered to the body as a function of time is given by

Two tuning forks have frequencies 450 Hz and 454 Hz respectively. On sounding these forks together, the time interval between successive maximum intensities will be [MP PET 1989; MP PMT 2003]

What is the refractive index of the material of a plano-convex lens, if the radius of curvature of the convex surface is 10 cm and focal length of the lens is 30 cm?

A charge (q, m) is projected perpendicular away from an infinitely long wire carrying a current i with a speed v0. Find the maximum separation between the charge and the wire in the subsequent motion if the initial separation is x0.

What is the coefficient of performance?

A block A of mass 7 kg is placed on a frictionless table. A thread tied to it passes over a frictionless pulley and carries a body B of mass 3 kg at the other end. The acceleration of the system is (given g=10 ms−2)

A ball falls from a height of 1 m on the ground and jumps upto a height H. If the coefficient of restitution of the collision is 0.9, then find the value of H. (Take g=10 m/s2)

The capacity of each condenser in the following fig. is ‘C’. Then the equivalent capacitance across A and B is?

A wooden cube just floats inside water with a 400 gm mass placed on it. When the mass is removed, the cube floats with its top surface 4 cm above the water level. What is the side of the cube?

A simple pendulum is suspended from the ceiling of a car taking a turn of radius 10 m at a speed of 36 km/h. Find the angle made by the string of the pendulum with the vertical if this angle does not change during the turn. Take g = 10 m/s2.

A series LCR circuit containing a resistor of 120 Ω has an angular resonant frequency 4×105 rad s−1. At resonance the voltages across resistor and inductor are 60 V and 40V respectively. The value of capacitance C is

A person's eye is at a height of 1.5m. He stands in front of a 0.3m long plane mirror whose lower end is 0.8m above the ground. The length of the image he sees himself is?

What is the difference between electric potential and potential difference?

A block of mass m is attached rigidly to a spring of stiffness k1 & touches another spring of stiffness k2 as shown in the figure. Assuming the surface is smooth, the period of oscillation of the block is