50278 + Interview Questions in Physics

1.	Two charges of q & 6q are placed at some distance, force acting on q is →F, then force on 6q is
Answer» Two charges of q & 6q are placed at some distance, force acting on q is $\to F$ , then force on 6q is

Discussion

2.	A particle is moving on a circular track of radius 4 m with speed v=t2−t+2. Find the acceleration of particle at t = 2 sec. ___
Answer» A particle is moving on a circular track of radius 4 m with speed $v = t^{2} - t + 2$ . Find the acceleration of particle at t = 2 sec. ___

Discussion

3.	Two blocks of equal mass are connected by a light string and placed on a smooth horizontal surface. If a force F acts on one of the block then the tension in the string is
Answer» Two blocks of equal mass are connected by a light string and placed on a smooth horizontal surface. If a force F acts on one of the block then the tension in the string is

3.

Two blocks of equal mass are connected by a light string and placed on a smooth horizontal surface. If a force F acts on one of the block then the tension in the string is

Answer»

Two blocks of equal mass are connected by a light string and placed on a smooth horizontal surface. If a force F acts on one of the block then the tension in the string is

Discussion

4.	A parallel combination of an 8 Ω resistor and an unknown resistor R is connected in series with a 16 Ω resistor and a battery. This circuit is then disassembled and the three resistors are connected in series with each other and the same battery. If in both arrangements, the current through the 8 Ω resistor is the same, then R is (Take √2 = 1.41) and write upto two digits after the decimal point.)
Answer» A parallel combination of an $8 Ω$ resistor and an unknown resistor R is connected in series with a $16 Ω$ resistor and a battery. This circuit is then disassembled and the three resistors are connected in series with each other and the same battery. If in both arrangements, the current through the $8 Ω$ resistor is the same, then R is (Take $\sqrt{2} = 1.41$ ) and write upto two digits after the decimal point.)

Discussion

5.	The change in potential energy, when a body of mass m is raised to a height nR from the earth's surface is (R = Radius of earth)
Answer» The change in potential energy, when a body of mass m is raised to a height nR from the earth's surface is (R = Radius of earth)

Discussion

6.	A cubical block is floating in a liquid with half of its volume immersed in the liquid. When the whole system accelerates upwards with acceleration of g/3, the fraction of volume immersed in the liquid will be
Answer» A cubical block is floating in a liquid with half of its volume immersed in the liquid. When the whole system accelerates upwards with acceleration of g/3, the fraction of volume immersed in the liquid will be

6.

A cubical block is floating in a liquid with half of its volume immersed in the liquid. When the whole system accelerates upwards with acceleration of g/3, the fraction of volume immersed in the liquid will be

Answer»

A cubical block is floating in a liquid with half of its volume immersed in the liquid. When the whole system accelerates upwards with acceleration of g/3, the fraction of volume immersed in the liquid will be

Discussion

7.	A particle reaches its highest point when it has covered exactly one half of its horizontal range. The corresponding point on the displacement time graph is characterised by
Answer» A particle reaches its highest point when it has covered exactly one half of its horizontal range. The corresponding point on the displacement time graph is characterised by

Discussion

8.	Two particles of equal masses are revolving in circular paths of radii r1 and r2 respectively with the same speed. The ratio of their centripetal forces is
Answer» Two particles of equal masses are revolving in circular paths of radii $r_{1} a n d r_{2}$ respectively with the same speed. The ratio of their centripetal forces is

Discussion

9.	The force constant of a wire is k and that of another wire is 2k. When both the wires are stretched through same distance, then the work done
Answer» The force constant of a wire is k and that of another wire is 2k. When both the wires are stretched through same distance, then the work done

9.

The force constant of a wire is k and that of another wire is 2k. When both the wires are stretched through same distance, then the work done

Answer»

The force constant of a wire is k and that of another wire is 2k. When both the wires are stretched through same distance, then the work done

Discussion

10.	The ratio of de-Broglie wavelength of a α -particle to that of a proton when they are subjected to the same magnetic field and their radii in the magnetic field are equal (assume the field induction vector →B is perpendicular to the velocity vectors of the α -particle and the proton) is
Answer» The ratio of de-Broglie wavelength of a $α$ -particle to that of a proton when they are subjected to the same magnetic field and their radii in the magnetic field are equal (assume the field induction vector $\to B$ is perpendicular to the velocity vectors of the $α$ -particle and the proton) is

Discussion

11.	The root mean square speed of the molecules of a gas is 1260 m/s. The average speed of the molecules is
Answer» The root mean square speed of the molecules of a gas is $1260 m/s$ . The average speed of the molecules is

Discussion

12.	A hot liquid is kept in a big room. The logarithm of the numerical value of the temperature difference between the liquid and the room is plotted against time. The plot will be very nearly:
Answer» A hot liquid is kept in a big room. The logarithm of the numerical value of the temperature difference between the liquid and the room is plotted against time. The plot will be very nearly:

Discussion

13.	A 400 Ω resistor, a 250 mH inductor and a 2.5 μF capacitor are connected in series with an AC source of peak voltage 5 V and angular frequency 2 kHz. What is the peak value of the electrostatic energy of the capacitor?
Answer» A 400 $Ω$ resistor, a 250 $m H$ inductor and a $2.5 μ F$ capacitor are connected in series with an $A C$ source of peak voltage 5 $V$ and angular frequency $2 k H z$ . What is the peak value of the electrostatic energy of the capacitor?

Discussion

14.	Two identical particles move towards each other with velocity 2v and v respectively. The velocity of the centre of mass is
Answer» Two identical particles move towards each other with velocity 2v and v respectively. The velocity of the centre of mass is

Discussion

15.	If a particle moves with velocity v(t)=(2t2−t) m/s, then find the velocity (in m/s) of particle at t=3 s.
Answer» If a particle moves with velocity $v (t) = (2 t^{2} - t) m / s$ , then find the velocity (in $m / s$ ) of particle at $t = 3 s$ .

Discussion

16.	Two point dipoles p^i and p√3^j are placed at origin. Find potential at point (4√3,4). (p=8√3 in MKS system)
Answer» Two point dipoles $p^i and p \sqrt{3}^j$ are placed at origin. Find potential at point $(4 \sqrt{3}, 4)$ . ( $p = 8 \sqrt{3}$ in MKS system)

Discussion

17.	There are two sources of electromagnetic waves, each emitting with a power of 100 W. one emits X – rays of wavelength 1 nm & the other visible light at 500 nm. The ratio of the number of photons of X – rays to the photons of visible light is
Answer» There are two sources of electromagnetic waves, each emitting with a power of 100 W. one emits X – rays of wavelength 1 nm & the other visible light at 500 nm. The ratio of the number of photons of X – rays to the photons of visible light is

Discussion

18.	A projectile is fired with some velocity making certain angle with the horizontal. Which of the following graphs is the best representation for the kinetic energy of a projectile (K.E) versus its horizontal displacement (x)?
Answer» A projectile is fired with some velocity making certain angle with the horizontal. Which of the following graphs is the best representation for the kinetic energy of a projectile $(K . E)$ versus its horizontal displacement $(x)$ ?

Discussion

19.	A charge particle q of mass m enters a magnetic field B as shown in figure. Speed of charge is V, then d is
Answer» A charge particle q of mass m enters a magnetic field B as shown in figure. Speed of charge is V, then d is

Discussion

20.	The maximum potential energy that the spring connecting blocks A and B can have as a consequence of collision of block C with A is (ignore any friction). Assume the collision between C and A to be elastic.
Answer» The maximum potential energy that the spring connecting blocks A and B can have as a consequence of collision of block C with A is (ignore any friction). Assume the collision between C and A to be elastic.

20.

The maximum potential energy that the spring connecting blocks A and B can have as a consequence of collision of block C with A is (ignore any friction). Assume the collision between C and A to be elastic.

Answer»

The maximum potential energy that the spring connecting blocks A and B can have as a consequence of collision of block C with A is (ignore any friction). Assume the collision between C and A to be elastic.

Discussion

21.	A smooth tunnel is dug along the radius of the earth that ends at the centre A ball is released from the surface of earth along the tunnel if the coefficient of restitution is 0.2 between the surface and ball then the total distance travelled by the ball before second collision at the centre.
Answer» A smooth tunnel is dug along the radius of the earth that ends at the centre A ball is released from the surface of earth along the tunnel if the coefficient of restitution is 0.2 between the surface and ball then the total distance travelled by the ball before second collision at the centre.

Discussion

22.	Planck's constant (h), speed of light in vacuum (c) and Newton's gravitational constant (G) are three fundamental constants. Which of the following combinations of these has the dimension of length?
Answer» Planck's constant ( $h$ ), speed of light in vacuum ( $c$ ) and Newton's gravitational constant ( $G$ ) are three fundamental constants. Which of the following combinations of these has the dimension of length?

Discussion

23.	The r.m.s value of electric field of the light coming from sun is 720 N/C. The average energy density of electromagnetic wave is
Answer» The r.m.s value of electric field of the light coming from sun is $720 N / C$ . The average energy density of electromagnetic wave is

Discussion

24.	Consider an elliptically shaped rail PQ in the vertical plane with OP = 3m and OQ = 4m. A block of mass 1 kg is pulled along the rail from P to Q with a force of 18 N, which is always parallel to line PQ (see the figure given). Assuming no frictional losses, the kinetic energy of the block when it reaches Q is (n × 10) joules. The value of n is (take acceleration due to gravity = 10 ms−2) .
Answer» Consider an elliptically shaped rail PQ in the vertical plane with OP = 3m and OQ = 4m. A block of mass 1 kg is pulled along the rail from P to Q with a force of 18 N, which is always parallel to line PQ (see the figure given). Assuming no frictional losses, the kinetic energy of the block when it reaches Q is (n $\times$ 10) joules. The value of n is (take acceleration due to gravity = $10 m s^{- 2}$ ) .

Discussion

25.	If cos(x−y),cos x,cos(x+y) are three distinct numbers which are harmonic progression and cos x≠cos y then 1+cosy=
Answer» If $c o s (x - y), c o s x, c o s (x + y)$ are three distinct numbers which are harmonic progression and $c o s x \neq c o s y$ then $1 + c o s y =$

Discussion

26.	Match the following : List−IList−IIA)Forbidden energy gapE)10−6mof a semiconductorF)1 MeVB)Knee voltage of germaniumG)0.7VdiodeC)Width of depletion layerH)1eVD)Forward voltage of silicon diodeI)0.3V
Answer» Match the following : $\begin{matrix} L i s t - I & L i s t - I I A) F o r b i d d e n e n e r g y g a p & E) 10^{- 6} m o f a s e m i c o n d u c t o r & F) 1 M e V B) K n e e v o l t a g e o f g e r m a n i u m & G) 0.7 V d i o d e C) W i d t h o f d e p l e t i o n l a y e r & H) 1 e V D) F o r w a r d v o l t a g e o f s i l i c o n d i o d e & I) 0.3 V \end{matrix}$

26.

Match the following : List−IList−IIA)Forbidden energy gapE)10−6mof a semiconductorF)1 MeVB)Knee voltage of germaniumG)0.7VdiodeC)Width of depletion layerH)1eVD)Forward voltage of silicon diodeI)0.3V

Answer»

Match the following :

$\begin{matrix} L i s t - I & L i s t - I I A) F o r b i d d e n e n e r g y g a p & E) 10^{- 6} m o f a s e m i c o n d u c t o r & F) 1 M e V B) K n e e v o l t a g e o f g e r m a n i u m & G) 0.7 V d i o d e C) W i d t h o f d e p l e t i o n l a y e r & H) 1 e V D) F o r w a r d v o l t a g e o f s i l i c o n d i o d e & I) 0.3 V \end{matrix}$

Discussion

27.	Two men are walking along a horizontal straight line in the same direction. The man in front walks at a speed of 1.0 ms−1 and the man behind walks at a speed of 2.0 ms−1. A third man is standing at a height 12 m above the same horizontal line such that all three men are in a vertical plane. The two walking men are blowing identical whistles which emit a sound of frequency 1430 Hz. The speed of sound in air is 330 ms−1. At the instant, when the moving men are 10 m apart, the stationary man is equidistant from them. The frequency of beats in Hz. heard by the stationary man at this instant, is ______
Answer» Two men are walking along a horizontal straight line in the same direction. The man in front walks at a speed of $1.0 m s^{- 1}$ and the man behind walks at a speed of $2.0 m s^{- 1}$ . A third man is standing at a height $12 m$ above the same horizontal line such that all three men are in a vertical plane. The two walking men are blowing identical whistles which emit a sound of frequency $1430 H z$ . The speed of sound in air is $330 m s^{- 1}$ . At the instant, when the moving men are $10 m$ apart, the stationary man is equidistant from them. The frequency of beats in $H z$ . heard by the stationary man at this instant, is ______

Discussion

28.	A car, starting from rest, accelerates at the rate f through a distance S, then continues at constant speed for time t and then decelerates at the rate f/2 to come to rest. If the total distance traversed is 15 S, then
Answer» A car, starting from rest, accelerates at the rate $f$ through a distance $S$ , then continues at constant speed for time $t$ and then decelerates at the rate $f / 2$ to come to rest. If the total distance traversed is $15 S$ , then

Discussion

29.	The dipole moment of a system of charge + q distributed uniformly on an arc of radius R subtending an angle π/2 at its centre where another charge −q is placed is √nqRπ. Then the value of n is (answer upto two decimal places)
Answer» The dipole moment of a system of charge + q distributed uniformly on an arc of radius R subtending an angle $π / 2$ at its centre where another charge $- q$ is placed is $\frac{\sqrt{n} q R}{π}$ . Then the value of $n$ is (answer upto two decimal places)

Discussion

30.	Block A & B of mass m each are connected with spring of constant k, both blocks lie on frictionless ground and are imparted horizontal velocity v as shown. Initially spring is unstretched, find the maximum extension of the spring.
Answer» Block $A$ & $B$ of mass $m$ each are connected with spring of constant $k$ , both blocks lie on frictionless ground and are imparted horizontal velocity $v$ as shown. Initially spring is unstretched, find the maximum extension of the spring.

Discussion

31.	Figure shows the variation of a force F acting on a particle along x- axis. If the particle begins at rest at (x=0), what is the particle's coordinate when it again has zero speed ?
Answer» Figure shows the variation of a force F acting on a particle along x- axis. If the particle begins at rest at (x=0), what is the particle's coordinate when it again has zero speed ?

31.

Figure shows the variation of a force F acting on a particle along x- axis. If the particle begins at rest at (x=0), what is the particle's coordinate when it again has zero speed ?

Answer»

Figure shows the variation of a force F acting on a particle along x- axis. If the particle begins at rest at (x=0), what is the particle's coordinate when it again has zero speed ?

Discussion

32.	In hydrogen atom the angular momentum of the electron in the lowest energy state is
Answer» In hydrogen atom the angular momentum of the electron in the lowest energy state is

Discussion

33.	A circular loop of wire carrying current is placed in the x - y plane such that its centre is at the origin of the assumed coordinate system of axes. If the current is clockwise as shown, what will be the direction of magnetic field at its centre?
Answer» A circular loop of wire carrying current is placed in the x - y plane such that its centre is at the origin of the assumed coordinate system of axes. If the current is clockwise as shown, what will be the direction of magnetic field at its centre?

Discussion

34.	Density ratio of O2 and H2 is 16:1. The ratio of their rate of effusion under same conditions is
Answer» Density ratio of $O_{2}$ and $H_{2}$ is $16 : 1$ . The ratio of their rate of effusion under same conditions is

Discussion

35.	Yellow light is used in single slit diffraction experiment with slit width 0.6 mm. If yellow light is replaced by X-rays then the pattern will reveal [IIT-JEE (Screening) 1999; MP PMT 2002; KCET 2003]
Answer» Yellow light is used in single slit diffraction experiment with slit width 0.6 mm. If yellow light is replaced by X-rays then the pattern will reveal [IIT-JEE (Screening) 1999; MP PMT 2002; KCET 2003]

Discussion

36.	A projectile is fired with some velocity making certain angle with the horizontal. Which of the following graphs is the best representation for the total kinetic energy of a projectile (KE) versus its horizontal displacement (x)?
Answer» A projectile is fired with some velocity making certain angle with the horizontal. Which of the following graphs is the best representation for the total kinetic energy of a projectile $(KE)$ versus its horizontal displacement $(x)$ ?

Discussion

37.	A body sliding on a smooth inclined plane requires 4 s to reach the bottom, starting from rest at the top. How much time does it take to cover one-fourth of the distance starting from rest at the top?
Answer» A body sliding on a smooth inclined plane requires $4 s$ to reach the bottom, starting from rest at the top. How much time does it take to cover one-fourth of the distance starting from rest at the top?

Discussion

38.	If a point (P) moves along a circle with constant speed. Ratio of its angular speed wrt any point (O) on circumference to angular speed wrt centre (C) of the circle is
Answer» If a point $(P)$ moves along a circle with constant speed. Ratio of its angular speed wrt any point $(O)$ on circumference to angular speed wrt centre $(C)$ of the circle is

Discussion

39.	A tube U - shaped has a uniform cross - section with arm length l1 and l2(l1>l2). Tube has a liquid of density ρ1 filled to a height h. Another liquid of density ρ2=ρ12 is poured in arm . Both liquids are immiscible. The length of the second liquid that should be poured in A so that first overtone of is in unison with fundamental tone of B is
Answer» A tube U - shaped has a uniform cross - section with arm length $l_{1}$ and $l_{2} (l_{1} > l_{2})$ . Tube has a liquid of density $ρ_{1}$ filled to a height h. Another liquid of density $ρ_{2} = \frac{ρ_{1}}{2}$ is poured in arm . Both liquids are immiscible. The length of the second liquid that should be poured in A so that first overtone of is in unison with fundamental tone of B is

39.

A tube U - shaped has a uniform cross - section with arm length l1 and l2(l1>l2). Tube has a liquid of density ρ1 filled to a height h. Another liquid of density ρ2=ρ12 is poured in arm . Both liquids are immiscible. The length of the second liquid that should be poured in A so that first overtone of is in unison with fundamental tone of B is

Answer»

A tube U - shaped has a uniform cross - section with arm length $l_{1}$ and $l_{2} (l_{1} > l_{2})$ . Tube has a liquid of density $ρ_{1}$ filled to a height h. Another liquid of density $ρ_{2} = \frac{ρ_{1}}{2}$ is poured in arm . Both liquids are immiscible. The length of the second liquid that should be poured in A so that first overtone of is in unison with fundamental tone of B is

Discussion

40.	A coin is placed at the edge of a horizontal disc rotating about a vertical axis through its centre with a uniform angular speed 2 rad s−1. The radius of the disc is 50 cm. Find the minimum coefficient of friction between disc and coin so that the coin does not slip (g=10 ms−2)
Answer» A coin is placed at the edge of a horizontal disc rotating about a vertical axis through its centre with a uniform angular speed $2 {rad s}^{- 1}$ . The radius of the disc is $50 cm$ . Find the minimum coefficient of friction between disc and coin so that the coin does not slip ( $g = 10 {ms}^{- 2}$ )

Discussion

41.	A conducting sphere A having a radius a is charged to a potential V1. Now it is surrounded by another conducting spherical shell of radius b. The potential V2 acquired by the sphere A after it is connected to shell B by a thin conducting wire is
Answer» A conducting sphere A having a radius a is charged to a potential $V_{1}$ . Now it is surrounded by another conducting spherical shell of radius b. The potential $V_{2}$ acquired by the sphere A after it is connected to shell B by a thin conducting wire is

Discussion

42.	In a parallel plate capacitor the separation between the plates is 3mm with air between them. Now a 1mm thick layer of a material of dielectric to the original value the separation between the plates must be made
Answer» In a parallel plate capacitor the separation between the plates is 3mm with air between them. Now a 1mm thick layer of a material of dielectric to the original value the separation between the plates must be made

Discussion

43.	When a source of sound of frequency f crosses a stationary observer with a speed vs(≪ speed of sound v), the apparent change in frequency Δ f is given by
Answer» When a source of sound of frequency f crosses a stationary observer with a speed $v_{s}$ (≪ speed of sound v), the apparent change in frequency $Δ$ f is given by

Discussion

44.	If energy (E), velocity (v) and force (F) be taken as fundamental quantity, then what are the dimensions of mass
Answer» If energy (E), velocity (v) and force (F) be taken as fundamental quantity, then what are the dimensions of mass

Discussion

45.	A uniform solid brass sphere is rotating with angular speed ω0 about a diameter. If its temperature is now increased by 100∘C. What will be its new angular speed? (Given αB=2×10−5∘C)
Answer» A uniform solid brass sphere is rotating with angular speed $ω_{0}$ about a diameter. If its temperature is now increased by $100^{\circ} C .$ What will be its new angular speed? (Given $α_{B} = 2 \times 10^{\frac{- 5}{^{\circ} C}})$

Discussion

46.	Metallic square loop ABCD is moving in its own plane with velocity V in a uniform magnetic field perpendicular to its plane as shown in the fig. An electric field is induced
Answer» Metallic square loop ABCD is moving in its own plane with velocity V in a uniform magnetic field perpendicular to its plane as shown in the fig. An electric field is induced

46.

Metallic square loop ABCD is moving in its own plane with velocity V in a uniform magnetic field perpendicular to its plane as shown in the fig. An electric field is induced

Answer»

Metallic square loop ABCD is moving in its own plane with velocity V in a uniform magnetic field perpendicular to its plane as shown in the fig. An electric field is induced

Discussion

47.	When a source of sound of frequency f crosses a stationery observer with a speed Vs (<< speed of sound V), the apparent change in frequency Δ F is given by
Answer» When a source of sound of frequency f crosses a stationery observer with a speed $V_{s}$ (<< speed of sound V), the apparent change in frequency $Δ$ F is given by

Discussion

48.	Four point charges, each of +q, are rigidly fixed at the four corners of a square planar soap film of side a. The surface tension of the soap film is η. The system of charges and planar film are in equilibrium, and a=k[q2γ]1/N, where k is a constant. Find the value of N. ___
Answer» Four point charges, each of +q, are rigidly fixed at the four corners of a square planar soap film of side a. The surface tension of the soap film is $η$ . The system of charges and planar film are in equilibrium, and $a = k {[\frac{q^{2}}{γ}]}^{1 / N}$ , where k is a constant. Find the value of N. ___

Discussion

49.	The given acceleration-time graph represent which of the following physical situations?
Answer» The given acceleration-time graph represent which of the following physical situations?

49.

The given acceleration-time graph represent which of the following physical situations?

Answer»

The given acceleration-time graph represent which of the following physical situations?

Discussion

50.	The figure shows a glass tube (linear co-efficient of expansion is α) completely filled with a liquid of volume expansion co-efficient γ. On heating, length of the liquid column does not change. Choose the correct relation between γ and α
Answer» The figure shows a glass tube (linear co-efficient of expansion is $α$ ) completely filled with a liquid of volume expansion co-efficient $γ$ . On heating, length of the liquid column does not change. Choose the correct relation between $γ a n d α$

Discussion

Explore topic-wise InterviewSolutions in Current Affairs.

Two charges of q &amp; 6q are placed at some distance, force acting on q is →F, then force on 6q is

A particle is moving on a circular track of radius 4 m with speed v=t2−t+2. Find the acceleration of particle at t = 2 sec. ___

Two blocks of equal mass are connected by a light string and placed on a smooth horizontal surface. If a force F acts on one of the block then the tension in the string is

The change in potential energy, when a body of mass m is raised to a height nR from the earth's surface is (R = Radius of earth)

A cubical block is floating in a liquid with half of its volume immersed in the liquid. When the whole system accelerates upwards with acceleration of g/3, the fraction of volume immersed in the liquid will be

A particle reaches its highest point when it has covered exactly one half of its horizontal range. The corresponding point on the displacement time graph is characterised by

Two particles of equal masses are revolving in circular paths of radii r1 and r2 respectively with the same speed. The ratio of their centripetal forces is

The force constant of a wire is k and that of another wire is 2k. When both the wires are stretched through same distance, then the work done

The ratio of de-Broglie wavelength of a α -particle to that of a proton when they are subjected to the same magnetic field and their radii in the magnetic field are equal (assume the field induction vector →B is perpendicular to the velocity vectors of the α -particle and the proton) is

The root mean square speed of the molecules of a gas is 1260 m/s. The average speed of the molecules is

A hot liquid is kept in a big room. The logarithm of the numerical value of the temperature difference between the liquid and the room is plotted against time. The plot will be very nearly:

A 400 Ω resistor, a 250 mH inductor and a 2.5 μF capacitor are connected in series with an AC source of peak voltage 5 V and angular frequency 2 kHz. What is the peak value of the electrostatic energy of the capacitor?

Two identical particles move towards each other with velocity 2v and v respectively. The velocity of the centre of mass is

If a particle moves with velocity v(t)=(2t2−t) m/s, then find the velocity (in m/s) of particle at t=3 s.

Two point dipoles p^i and p√3^j are placed at origin. Find potential at point (4√3,4). (p=8√3 in MKS system)

There are two sources of electromagnetic waves, each emitting with a power of 100 W. one emits X – rays of wavelength 1 nm &amp; the other visible light at 500 nm. The ratio of the number of photons of X – rays to the photons of visible light is

A projectile is fired with some velocity making certain angle with the horizontal. Which of the following graphs is the best representation for the kinetic energy of a projectile (K.E) versus its horizontal displacement (x)?

A charge particle q of mass m enters a magnetic field B as shown in figure. Speed of charge is V, then d is

The maximum potential energy that the spring connecting blocks A and B can have as a consequence of collision of block C with A is (ignore any friction). Assume the collision between C and A to be elastic.

A smooth tunnel is dug along the radius of the earth that ends at the centre A ball is released from the surface of earth along the tunnel if the coefficient of restitution is 0.2 between the surface and ball then the total distance travelled by the ball before second collision at the centre.

Planck's constant (h), speed of light in vacuum (c) and Newton's gravitational constant (G) are three fundamental constants. Which of the following combinations of these has the dimension of length?

The r.m.s value of electric field of the light coming from sun is 720 N/C. The average energy density of electromagnetic wave is

If cos(x−y),cos x,cos(x+y) are three distinct numbers which are harmonic progression and cos x≠cos y then 1+cosy=

Match the following : List−IList−IIA)Forbidden energy gapE)10−6mof a semiconductorF)1 MeVB)Knee voltage of germaniumG)0.7VdiodeC)Width of depletion layerH)1eVD)Forward voltage of silicon diodeI)0.3V

A car, starting from rest, accelerates at the rate f through a distance S, then continues at constant speed for time t and then decelerates at the rate f/2 to come to rest. If the total distance traversed is 15 S, then

The dipole moment of a system of charge + q distributed uniformly on an arc of radius R subtending an angle π/2 at its centre where another charge −q is placed is √nqRπ. Then the value of n is (answer upto two decimal places)

Block A &amp; B of mass m each are connected with spring of constant k, both blocks lie on frictionless ground and are imparted horizontal velocity v as shown. Initially spring is unstretched, find the maximum extension of the spring.

Figure shows the variation of a force F acting on a particle along x- axis. If the particle begins at rest at (x=0), what is the particle's coordinate when it again has zero speed ?

In hydrogen atom the angular momentum of the electron in the lowest energy state is

A circular loop of wire carrying current is placed in the x - y plane such that its centre is at the origin of the assumed coordinate system of axes. If the current is clockwise as shown, what will be the direction of magnetic field at its centre?

Density ratio of O2 and H2 is 16:1. The ratio of their rate of effusion under same conditions is

Yellow light is used in single slit diffraction experiment with slit width 0.6 mm. If yellow light is replaced by X-rays then the pattern will reveal [IIT-JEE (Screening) 1999; MP PMT 2002; KCET 2003]

A projectile is fired with some velocity making certain angle with the horizontal. Which of the following graphs is the best representation for the total kinetic energy of a projectile (KE) versus its horizontal displacement (x)?

A body sliding on a smooth inclined plane requires 4 s to reach the bottom, starting from rest at the top. How much time does it take to cover one-fourth of the distance starting from rest at the top?

If a point (P) moves along a circle with constant speed. Ratio of its angular speed wrt any point (O) on circumference to angular speed wrt centre (C) of the circle is

A coin is placed at the edge of a horizontal disc rotating about a vertical axis through its centre with a uniform angular speed 2 rad s−1. The radius of the disc is 50 cm. Find the minimum coefficient of friction between disc and coin so that the coin does not slip (g=10 ms−2)

A conducting sphere A having a radius a is charged to a potential V1. Now it is surrounded by another conducting spherical shell of radius b. The potential V2 acquired by the sphere A after it is connected to shell B by a thin conducting wire is

In a parallel plate capacitor the separation between the plates is 3mm with air between them. Now a 1mm thick layer of a material of dielectric to the original value the separation between the plates must be made

When a source of sound of frequency f crosses a stationary observer with a speed vs(≪ speed of sound v), the apparent change in frequency Δ f is given by

If energy (E), velocity (v) and force (F) be taken as fundamental quantity, then what are the dimensions of mass

A uniform solid brass sphere is rotating with angular speed ω0 about a diameter. If its temperature is now increased by 100∘C. What will be its new angular speed? (Given αB=2×10−5∘C)

Metallic square loop ABCD is moving in its own plane with velocity V in a uniform magnetic field perpendicular to its plane as shown in the fig. An electric field is induced

When a source of sound of frequency f crosses a stationery observer with a speed Vs (&lt;&lt; speed of sound V), the apparent change in frequency Δ F is given by

Four point charges, each of +q, are rigidly fixed at the four corners of a square planar soap film of side a. The surface tension of the soap film is η. The system of charges and planar film are in equilibrium, and a=k[q2γ]1/N, where k is a constant. Find the value of N. ___

The given acceleration-time graph represent which of the following physical situations?

The figure shows a glass tube (linear co-efficient of expansion is α) completely filled with a liquid of volume expansion co-efficient γ. On heating, length of the liquid column does not change. Choose the correct relation between γ and α

Two charges of q & 6q are placed at some distance, force acting on q is →F, then force on 6q is

There are two sources of electromagnetic waves, each emitting with a power of 100 W. one emits X – rays of wavelength 1 nm & the other visible light at 500 nm. The ratio of the number of photons of X – rays to the photons of visible light is

Block A & B of mass m each are connected with spring of constant k, both blocks lie on frictionless ground and are imparted horizontal velocity v as shown. Initially spring is unstretched, find the maximum extension of the spring.

When a source of sound of frequency f crosses a stationery observer with a speed Vs (<< speed of sound V), the apparent change in frequency Δ F is given by