50278 + Interview Questions in Physics

1.	If ABCD is a rhombus whose diagonals are represented by −−→AC=^i+(1+λ)^j+(λ−2)^k and −−→BD=(2λ−1)^i+^j−^k, then λ equals to
Answer» If $A B C D$ is a rhombus whose diagonals are represented by $- - \to A C =^i + (1 + λ)^j + (λ - 2)^k$ and $- - \to B D = (2 λ - 1)^i +^j -^k,$ then $λ$ equals to

Discussion

2.	A ball of mass 1 kg is falling under gravity in a viscous medium. The drag force on it is given by 0.5u, where u is the instantaneous speed. If upthrust force on it is 5 N, then terminal speed (in m/s) is (take g=10 ms−2)
Answer» A ball of mass $1 kg$ is falling under gravity in a viscous medium. The drag force on it is given by $0.5 u$ , where $u$ is the instantaneous speed. If upthrust force on it is $5 N$ , then terminal speed (in $m/s$ ) is (take $g = 10 {ms}^{- 2}$ )

Discussion

3.	Two springs A and B (kA = 2kB) are stretched by applying forces of equal magnitudes at the four ends. If the energy stored in A is E, that in B is
Answer» Two springs A and B ( $k_{A}$ = 2 $k_{B}$ ) are stretched by applying forces of equal magnitudes at the four ends. If the energy stored in A is E, that in B is

Discussion

4.	A 2 kg ball is swinging in a vertical circle at the end of an inextensible string 2 m long. The angular speed of the ball if the string can sustain a maximum tension of 119.6 N is (Take g=9.8 m/s2)
Answer» A $2 kg$ ball is swinging in a vertical circle at the end of an inextensible string $2 m$ long. The angular speed of the ball if the string can sustain a maximum tension of $119.6 N$ is (Take $g = 9.8 {m/s}^{2}$ )

Discussion

5.	The variation of the intensity of magnetisation (I) with respect to the magnetising field (H) in a diamagnetic substance is described by the graph.
Answer» The variation of the intensity of magnetisation $(I)$ with respect to the magnetising field $(H)$ in a diamagnetic substance is described by the graph.

Discussion

6.	a rope is wound around a hollow cylinder of mass 3kg and radius 40cm.what is the angular acceleration of the cylinder if the rope is pulled with a force of 30N
Answer» a rope is wound around a hollow cylinder of mass 3kg and radius 40cm.what is the angular acceleration of the cylinder if the rope is pulled with a force of 30N

Discussion

7.	Which one of the following is the bending moment diagram for the vertical cantilever beam loaded as shown in figure?
Answer» Which one of the following is the bending moment diagram for the vertical cantilever beam loaded as shown in figure?

Discussion

8.	A resistance coil of 60ohms is immersed in 42kg of water. A current of 7A is passed through it. The rise in temperature of water per minute is
Answer» A resistance coil of 60ohms is immersed in 42kg of water. A current of 7A is passed through it. The rise in temperature of water per minute is

Discussion

9.	29. The first,second and third ionization energies are 578,1187and 2745 kj/mol respectively.calculate the energy required to convert all the atoms of Al+3 present in 270 mg of Al vapours?
Answer» 29. The first,second and third ionization energies are 578,1187and 2745 kj/mol respectively.calculate the energy required to convert all the atoms of Al+3 present in 270 mg of Al vapours?

Discussion

10.	The Bat Life: Batman is undercover, and to prevent anyone from recognizing his voice (or Bruce Wayne's) he inhales a very dilute Helium gas (search YouTube for "voice after helium” to see the effects). The helium is stored ina cylindrical chamber as shown. During a fight one of the steel balls gets dislodged. What will happen to the piston?
Answer» The Bat Life: Batman is undercover, and to prevent anyone from recognizing his voice (or Bruce Wayne's) he inhales a very dilute Helium gas (search YouTube for "voice after helium” to see the effects). The helium is stored ina cylindrical chamber as shown. During a fight one of the steel balls gets dislodged. What will happen to the piston?

10.

The Bat Life: Batman is undercover, and to prevent anyone from recognizing his voice (or Bruce Wayne's) he inhales a very dilute Helium gas (search YouTube for "voice after helium” to see the effects). The helium is stored ina cylindrical chamber as shown. During a fight one of the steel balls gets dislodged. What will happen to the piston?

Answer»

The Bat Life: Batman is undercover, and to prevent anyone from recognizing his voice (or Bruce Wayne's) he inhales a very dilute Helium gas (search YouTube for "voice after helium” to see the effects). The helium is stored ina cylindrical chamber as shown.

During a fight one of the steel balls gets dislodged. What will happen to the piston?

Discussion

11.	A man of mass m stands on a create of mass M. He pulls on a light rope passing over a smooth light pulley. The other end of the rope is attached to the crate. For the system to be in equilibrium, the force exerted by the men on the rope will be
Answer» A man of mass m stands on a create of mass M. He pulls on a light rope passing over a smooth light pulley. The other end of the rope is attached to the crate. For the system to be in equilibrium, the force exerted by the men on the rope will be

11.

A man of mass m stands on a create of mass M. He pulls on a light rope passing over a smooth light pulley. The other end of the rope is attached to the crate. For the system to be in equilibrium, the force exerted by the men on the rope will be

Answer»

A man of mass m stands on a create of mass M. He pulls on a light rope passing over a smooth light pulley. The other end of the rope is attached to the crate. For the system to be in equilibrium, the force exerted by the men on the rope will be

Discussion

12.	17.In an LCR circuit the resonating frequency is 500 KHZ. if the value of L is doubled and value of C is decreased to 1/8 times of initial values, then the new resonating frequency in KHZ will be?
Answer» 17.In an LCR circuit the resonating frequency is 500 KHZ. if the value of L is doubled and value of C is decreased to 1/8 times of initial values, then the new resonating frequency in KHZ will be?

Discussion

13.	52.Motor operates on a 50 volt supply and a current of 12 A. The efficiency of the motor is 30%what is the resistance of the winding a motor?
Answer» 52.Motor operates on a 50 volt supply and a current of 12 A. The efficiency of the motor is 30%what is the resistance of the winding a motor?

Discussion

14.	Two small angled transparent prisms (each of refracting angle A=1∘) are so placed that their bases coincide, so that common base is BC. This device is called Fresnel’s biprism and is used to obtain coherent sources of a point source S illuminated by monochromatic light of wavelength 6000 ∘A placed at a distance a=20 cm. Calculate the separation between coherent sources. If a screen is placed at a distance b=80\text{cm}\) from the device, what is the fringe width of fringes (in cm) obtained (Refractive index of material of each prism = 1.5).
Answer» Two small angled transparent prisms (each of refracting angle $A = 1^{\circ}$ ) are so placed that their bases coincide, so that common base is BC. This device is called Fresnel’s biprism and is used to obtain coherent sources of a point source S illuminated by monochromatic light of wavelength $6000 \circ A$ placed at a distance $a = 20 cm$ . Calculate the separation between coherent sources. If a screen is placed at a distance $b = 80$ \text{cm}\) from the device, what is the fringe width of fringes (in cm) obtained (Refractive index of material of each prism = 1.5).

Discussion

15.	Figure shows a capillary tube of radius r dipped into water. The atmospheric pressure is P0 and the capillary rise of water is h. s is the surface tension for water-glass.Which of the following graphs may represent the relation between the capillary rise h and the radius r of the capillary?
Answer» Figure shows a capillary tube of radius $r$ dipped into water. The atmospheric pressure is $P_{0}$ and the capillary rise of water is $h$ . $s$ is the surface tension for water-glass. Which of the following graphs may represent the relation between the capillary rise $h$ and the radius $r$ of the capillary?

Discussion

16.	Find the amplitude of vibration of the particles of air through which a sound wave of intensity 2.0 × 10−6W m−2 and frequency 1.0 kHz is passing. Density of air =1.2 kgm−3and speed of sound in air =330ms−1
Answer» Find the amplitude of vibration of the particles of air through which a sound wave of intensity $2.0 \times 10^{- 6} W m^{- 2}$ and frequency 1.0 kHz is passing. Density of air = $1.2 k g m^{- 3}$ and speed of sound in air = $330 m s^{- 1}$

Discussion

17.	When ultraviolet rays are incident on metal plate, then photoelectric effect does not occurs. It occurs by the incidence of
Answer» When ultraviolet rays are incident on metal plate, then photoelectric effect does not occurs. It occurs by the incidence of

Discussion

18.	Two wave with same frequency and wave number are propagating in the same direction. The ratio of their amplitude is 5:1 . If interference occurs, the ratio of maximum and minimum intensity should be
Answer» Two wave with same frequency and wave number are propagating in the same direction. The ratio of their amplitude is $5 : 1$ . If interference occurs, the ratio of maximum and minimum intensity should be

Discussion

19.	A concave lens forms the image of an object such that the dis†an ce between the object and image is 10cm. If magnification of the image is 1/4. The focal length of the lens is (1) 6cm (2) 20/3 cm (3) 10/7 cm (4) 40/9 cm.
Answer» A concave lens forms the image of an object such that the dis†an ce between the object and image is 10cm. If magnification of the image is 1/4. The focal length of the lens is (1) 6cm (2) 20/3 cm (3) 10/7 cm (4) 40/9 cm.

Discussion

20.	Four charge particles He++, proton, deutron and Li++ enters a region of uniform magnetic field and moves in a circular path of different radius. List I gives above four particles while list II gives magnitude of some quantity.List IList III - He++P) 1II - ProtonQ) 2III - deutronR) 1√2IV) Li++S) √2T) √72U) 12If kinetic energy of all four particles is same than correct match for radius of four particles in units of radius of proton is
Answer» Four charge particles $H e^{+ +}$ , proton, deutron and $L i^{+ +}$ enters a region of uniform magnetic field and moves in a circular path of different radius. List I gives above four particles while list II gives magnitude of some quantity. $\begin{matrix} List I & List II I - H e^{+ +} & P) 1 II - Proton & Q) 2 III - deutron & R) \frac{1}{\sqrt{2}} IV) L i^{+ +} & S) \sqrt{2} T) \frac{\sqrt{7}}{2} U) \frac{1}{2} \end{matrix}$ If kinetic energy of all four particles is same than correct match for radius of four particles in units of radius of proton is

Discussion

21.	45. Proof that if any body sleep down respectively an incline plane then its accelaration decreases u=meu mgcosthita
Answer» 45. Proof that if any body sleep down respectively an incline plane then its accelaration decreases u=meu mgcosthita

Discussion

22.	A stone of mass 20 g is projected from a rubber catapult of length 0.1 m and area of cross section 10–6 m2 stretched by an amount 0.04 m. The velocity of the projected stone is ____ m/s. (Young's modulus of rubber =0.5×109 N/m2)
Answer» A stone of mass $20 g$ is projected from a rubber catapult of length $0.1 m$ and area of cross section $10^{- 6} m^{2}$ stretched by an amount $0.04 m$ . The velocity of the projected stone is ____ $m/s$ . (Young's modulus of rubber $= 0.5 \times 10^{9} N / m^{2}$ )

Discussion

23.	The acceleration of a particle is increasing linearly with time t as bt. The particle starts from rest from the origin. The velocity will be proportional to
Answer» The acceleration of a particle is increasing linearly with time $t$ as $b t$ . The particle starts from rest from the origin. The velocity will be proportional to

Discussion

24.	A particle of mass 64M and another particle of mass 36M are placed at a distance 8d and 6d respectively from a particle of mass m. find the net gravitational force on m
Answer» A particle of mass 64M and another particle of mass 36M are placed at a distance 8d and 6d respectively from a particle of mass m. find the net gravitational force on m

Discussion

25.	a block of mass m having charge q is hanging vertically with the help of spring of spring cons†an t k. Now vertical electric field E is switched on. if spring attains its natural length when block comes a rest then strength of electric field i
Answer» a block of mass m having charge q is hanging vertically with the help of spring of spring cons†an t k. Now vertical electric field E is switched on. if spring attains its natural length when block comes a rest then strength of electric field i

Discussion

26.	Two blocks of masses 3 kgand 6 kg respectively are placed on a smooth horizontal surface. They are connected by a light spring of force constant k=200N/m. Initially the spring is unstretched. The indicated velocities are imparted to the blocks. Find the maximum extension of the spring.
Answer» Two blocks of masses $3 kg$ and $6 kg$ respectively are placed on a smooth horizontal surface. They are connected by a light spring of force constant $k = 200 N/m$ . Initially the spring is unstretched. The indicated velocities are imparted to the blocks. Find the maximum extension of the spring.

Discussion

27.	For a series LCR circuit, L=2 H,C=32 μF and R=10 Ω. What will be the magnitude of Q-factor at resonance?
Answer» For a series LCR circuit, $L = 2 H, C = 32 μ F$ and $R = 10 Ω$ . What will be the magnitude of Q-factor at resonance?

Discussion

28.	how to solve rational derivatives ??s=t^3- 3t + 4/t^2find ds/dt
Answer» how to solve rational derivatives ?? s=t^3- 3t + 4/t^2 find ds/dt

Discussion

29.	The product of resistivity and coductivity depends on
Answer» The product of resistivity and coductivity depends on

Discussion

30.	A proton and α− particle are accelerated through the same potential. The ratio of de Broglie wavelength of the proton to α− particle will be is X. Then, the value of X2 is
Answer» A proton and $α -$ particle are accelerated through the same potential. The ratio of de Broglie wavelength of the proton to $α -$ particle will be is $X .$ Then, the value of $X^{2}$ is

Discussion

31.	The longest wavelength in Lyman series of hydrogen atom spectrum corresponding to Hα line is approximately.
Answer» The longest wavelength in Lyman series of hydrogen atom spectrum corresponding to $H_{α}$ line is approximately.

Discussion

32.	a ball is thrown from ground with speed u at an angle theta with the horizontal ,at the same ins†an t from the same position a boy runs along the ground with speed \sqrt3/2 to catch the ball.if the boy is able to catch the ball,the angle of projection theta is
Answer» a ball is thrown from ground with speed u at an angle theta with the horizontal ,at the same ins†an t from the same position a boy runs along the ground with speed \sqrt3/2 to catch the ball.if the boy is able to catch the ball,the angle of projection theta is

Discussion

33.	Figure shows , three spherical and equipotential surfaces (marked 1,2 and 3 in the figure) around a point charge q. If the potential difference V1−V2=V2−V3 and t1 and t2 be the distances between them, then which of the following is true?
Answer» Figure shows , three spherical and equipotential surfaces (marked $1, 2$ and $3$ in the figure) around a point charge $q$ . If the potential difference $V_{1} - V_{2} = V_{2} - V_{3}$ and $t_{1}$ and $t_{2}$ be the distances between them, then which of the following is true?

Discussion

34.	Find the fundamental, first overtone and second overtone frequencies of an open organ pipe of length 20 cm. Speed of sound in air is 340ms−1.
Answer» Find the fundamental, first overtone and second overtone frequencies of an open organ pipe of length 20 cm. Speed of sound in air is 340 $m s^{- 1}$ .

Discussion

35.	A square plate of side l is placed on the principal axis at focal point F of a convex mirror such that the principal axis is passes through the centre of plate normally .the area of image of the plate is
Answer» A square plate of side l is placed on the principal axis at focal point F of a convex mirror such that the principal axis is passes through the centre of plate normally .the area of image of the plate is

Discussion

36.	At what height over the earths pole the free fall acceleration decreases by one percent? (Radius of earth =6400Km) H=16kmH=32kmH=64kmH=128Km
Answer» At what height over the earths pole the free fall acceleration decreases by one percent? (Radius of earth =6400Km) H=16km H=32km H=64km H=128Km

Discussion

37.	{ 82. A metal rod of resistance }R is fixed along a diameter of }}{ a conducting ring of radius }r . There is a magnetic field }}{ of induction }B perpendicular to the plane of the ring. }}{ The ring is spinning with an angular velocity }ω about }} its axis. The centre of the ring is joined to its rim by } an external wire. The ring and the wire have negligible } resistance. The current in the wire is
Answer» { 82. A metal rod of resistance }R is fixed along a diameter of }}{ a conducting ring of radius }r . There is a magnetic field }}{ of induction }B perpendicular to the plane of the ring. }}{ The ring is spinning with an angular velocity }ω about }} its axis. The centre of the ring is joined to its rim by } an external wire. The ring and the wire have negligible } resistance. The current in the wire is

Discussion

38.	A ball whose mass is 100 g is dropped from a height of 2 m from the floor. It rebounds vertically upwards after colliding with the floor to a height 1.5 m. Find (a) the momentum of the ball before and after colliding with the floor, (b) the average force exerted by the floor on the ball. Assume that collision lasts for 10−8 s.
Answer» A ball whose mass is 100 g is dropped from a height of 2 m from the floor. It rebounds vertically upwards after colliding with the floor to a height 1.5 m. Find (a) the momentum of the ball before and after colliding with the floor, (b) the average force exerted by the floor on the ball. Assume that collision lasts for $10^{- 8} s$ .

Discussion

39.	if y=1÷ a-z find dz÷ dy
Answer» if y=1÷ a-z find dz÷ dy

Discussion

40.	calculate the electric dipole moment of and an electron and proton 0.53 armstrong apart
Answer» calculate the electric dipole moment of and an electron and proton 0.53 armstrong apart

Discussion

41.	A point charge q is kept at the center of a fixed semi circular thread having a uniform charges per unit length λ , the radius of the semi circular thread being R . The force required to keep the charge stationary is ??
Answer» A point charge q is kept at the center of a fixed semi circular thread having a uniform charges per unit length λ , the radius of the semi circular thread being R . The force required to keep the charge stationary is ??

Discussion

42.	Acceleration of the particle in a rectilinear motion is given as a=2t−2 in (m/s2). The final position of the particle as a function of time t is(Given that at t=0,u=2 m/s,x=4 m)
Answer» Acceleration of the particle in a rectilinear motion is given as $a = 2 t - 2$ in $(m / s^{2})$ . The final position of the particle as a function of time $t$ is (Given that at $t = 0, u = 2 m / s, x = 4 m$ )

Discussion

43.	A block of mass 2 kg rests on a rough inclined plane making an angle of 30∘ with the horizontal. The coefficient of static friction between the block and the plane is 0.7. The frictional force on the block is
Answer» A block of mass $2 kg$ rests on a rough inclined plane making an angle of $30^{\circ}$ with the horizontal. The coefficient of static friction between the block and the plane is $0.7$ . The frictional force on the block is

Discussion

44.	A particle of mass m and charge Q is placed in an electric field of intensity E, which varies with time t as E=E0 sin ωt. It will undergo simple harmonic motion of amplitude
Answer» A particle of mass $m$ and charge $Q$ is placed in an electric field of intensity $E,$ which varies with time $t$ as $E = E_{0} sin ω t .$ It will undergo simple harmonic motion of amplitude

Discussion

45.	Truth table for the given circuit is
Answer» Truth table for the given circuit is

Discussion

46.	The number of photons of wavelength 540 nm emitted per second by an electric bulb of power 100W is (taking h=6×10−34J−sec).
Answer» The number of photons of wavelength 540 nm emitted per second by an electric bulb of power 100W is (taking $h = 6 \times 10^{- 34} J - s e c)$ .

Discussion

47.	a particle is thrown vertically up with speed u so that dis†an ce covered in last second of flight is 35m.if g=10m/s2 then initial speed of throw i
Answer» a particle is thrown vertically up with speed u so that dis†an ce covered in last second of flight is 35m.if g=10m/s2 then initial speed of throw i

Discussion

48.	Two bodies of mass 1 Kg and 3 Kg have position vectors ^i+2^j+^k and −3^i−2^j+^k respectively. The centre of mass of this system has a position vector
Answer» Two bodies of mass $1 Kg$ and $3 Kg$ have position vectors $^i + 2^j +^k$ and $- 3^i - 2^j +^k$ respectively. The centre of mass of this system has a position vector

Discussion

49.	A bike moving al9ng a straight road covers 35m in 4th second and 40m in the 5th second. What is its initial velocity and acceleration (of the acceleration is assumed to be uniform)?
Answer» A bike moving al9ng a straight road covers 35m in 4th second and 40m in the 5th second. What is its initial velocity and acceleration (of the acceleration is assumed to be uniform)?

Discussion

50.	64.A circuit given in the figure has section AB , with E=10V,C1=1 if, C2=2uF & the potential difference Va-Vb=5 V.the voltage across C1 is A. 0 B. 5V C. 10V D. 15V
Answer» 64.A circuit given in the figure has section AB , with E=10V,C1=1 if, C2=2uF & the potential difference Va-Vb=5 V.the voltage across C1 is A. 0 B. 5V C. 10V D. 15V

Discussion

Explore topic-wise InterviewSolutions in Current Affairs.

If ABCD is a rhombus whose diagonals are represented by −−→AC=^i+(1+λ)^j+(λ−2)^k and −−→BD=(2λ−1)^i+^j−^k, then λ equals to

A ball of mass 1 kg is falling under gravity in a viscous medium. The drag force on it is given by 0.5u, where u is the instantaneous speed. If upthrust force on it is 5 N, then terminal speed (in m/s) is ​​​​​​​(take g=10 ms−2)

Two springs A and B (kA = 2kB) are stretched by applying forces of equal magnitudes at the four ends. If the energy stored in A is E, that in B is

A 2 kg ball is swinging in a vertical circle at the end of an inextensible string 2 m long. The angular speed of the ball if the string can sustain a maximum tension of 119.6 N is (Take g=9.8 m/s2)

The variation of the intensity of magnetisation (I) with respect to the magnetising field (H) in a diamagnetic substance is described by the graph.

a rope is wound around a hollow cylinder of mass 3kg and radius 40cm.what is the angular acceleration of the cylinder if the rope is pulled with a force of 30N

Which one of the following is the bending moment diagram for the vertical cantilever beam loaded as shown in figure?

A resistance coil of 60ohms is immersed in 42kg of water. A current of 7A is passed through it. The rise in temperature of water per minute is

29. The first,second and third ionization energies are 578,1187and 2745 kj/mol respectively.calculate the energy required to convert all the atoms of Al+3 present in 270 mg of Al vapours?

A man of mass m stands on a create of mass M. He pulls on a light rope passing over a smooth light pulley. The other end of the rope is attached to the crate. For the system to be in equilibrium, the force exerted by the men on the rope will be

17.In an LCR circuit the resonating frequency is 500 KHZ. if the value of L is doubled and value of C is decreased to 1/8 times of initial values, then the new resonating frequency in KHZ will be?

52.Motor operates on a 50 volt supply and a current of 12 A. The efficiency of the motor is 30%what is the resistance of the winding a motor?

Figure shows a capillary tube of radius r dipped into water. The atmospheric pressure is P0 and the capillary rise of water is h. s is the surface tension for water-glass.Which of the following graphs may represent the relation between the capillary rise h and the radius r of the capillary?

Find the amplitude of vibration of the particles of air through which a sound wave of intensity 2.0 × 10−6W m−2 and frequency 1.0 kHz is passing. Density of air =1.2 kgm−3and speed of sound in air =330ms−1

When ultraviolet rays are incident on metal plate, then photoelectric effect does not occurs. It occurs by the incidence of

Two wave with same frequency and wave number are propagating in the same direction. The ratio of their amplitude is 5:1 . If interference occurs, the ratio of maximum and minimum intensity should be

A concave lens forms the image of an object such that the dis†an ce between the object and image is 10cm. If magnification of the image is 1/4. The focal length of the lens is (1) 6cm (2) 20/3 cm (3) 10/7 cm (4) 40/9 cm.

45. Proof that if any body sleep down respectively an incline plane then its accelaration decreases u=meu mgcosthita

A stone of mass 20 g is projected from a rubber catapult of length 0.1 m and area of cross section 10–6 m2 stretched by an amount 0.04 m. The velocity of the projected stone is ____ m/s. (Young's modulus of rubber =0.5×109 N/m2)

The acceleration of a particle is increasing linearly with time t as bt. The particle starts from rest from the origin. The velocity will be proportional to

A particle of mass 64M and another particle of mass 36M are placed at a distance 8d and 6d respectively from a particle of mass m. find the net gravitational force on m

a block of mass m having charge q is hanging vertically with the help of spring of spring cons†an t k. Now vertical electric field E is switched on. if spring attains its natural length when block comes a rest then strength of electric field i

Two blocks of masses 3 kgand 6 kg respectively are placed on a smooth horizontal surface. They are connected by a light spring of force constant k=200N/m. Initially the spring is unstretched. The indicated velocities are imparted to the blocks. Find the maximum extension of the spring.

For a series LCR circuit, L=2 H,C=32 μF and R=10 Ω. What will be the magnitude of Q-factor at resonance?

how to solve rational derivatives ??s=t^3- 3t + 4/t^2find ds/dt

The product of resistivity and coductivity depends on

A proton and α− particle are accelerated through the same potential. The ratio of de Broglie wavelength of the proton to α− particle will be is X. Then, the value of X2 is

The longest wavelength in Lyman series of hydrogen atom spectrum corresponding to Hα line is approximately.

a ball is thrown from ground with speed u at an angle theta with the horizontal ,at the same ins†an t from the same position a boy runs along the ground with speed \sqrt3/2 to catch the ball.if the boy is able to catch the ball,the angle of projection theta is

Figure shows , three spherical and equipotential surfaces (marked 1,2 and 3 in the figure) around a point charge q. If the potential difference V1−V2=V2−V3 and t1 and t2 be the distances between them, then which of the following is true?

Find the fundamental, first overtone and second overtone frequencies of an open organ pipe of length 20 cm. Speed of sound in air is 340ms−1.

A square plate of side l is placed on the principal axis at focal point F of a convex mirror such that the principal axis is passes through the centre of plate normally .the area of image of the plate is

At what height over the earths pole the free fall acceleration decreases by one percent? (Radius of earth =6400Km) H=16kmH=32kmH=64kmH=128Km

if y=1÷ a-z find dz÷ dy

calculate the electric dipole moment of and an electron and proton 0.53 armstrong apart

A point charge q is kept at the center of a fixed semi circular thread having a uniform charges per unit length λ , the radius of the semi circular thread being R . The force required to keep the charge stationary is ??

Acceleration of the particle in a rectilinear motion is given as a=2t−2 in (m/s2). The final position of the particle as a function of time t is(Given that at t=0,u=2 m/s,x=4 m)

A block of mass 2 kg rests on a rough inclined plane making an angle of 30∘ with the horizontal. The coefficient of static friction between the block and the plane is 0.7. The frictional force on the block is

A particle of mass m and charge Q is placed in an electric field of intensity E, which varies with time t as E=E0 sin ωt. It will undergo simple harmonic motion of amplitude

Truth table for the given circuit is

The number of photons of wavelength 540 nm emitted per second by an electric bulb of power 100W is (taking h=6×10−34J−sec).

a particle is thrown vertically up with speed u so that dis†an ce covered in last second of flight is 35m.if g=10m/s2 then initial speed of throw i

Two bodies of mass 1 Kg and 3 Kg have position vectors ^i+2^j+^k and −3^i−2^j+^k respectively. The centre of mass of this system has a position vector

A bike moving al9ng a straight road covers 35m in 4th second and 40m in the 5th second. What is its initial velocity and acceleration (of the acceleration is assumed to be uniform)?

64.A circuit given in the figure has section AB , with E=10V,C1=1 if, C2=2uF & the potential difference Va-Vb=5 V.the voltage across C1 is A. 0 B. 5V C. 10V D. 15V

A ball of mass 1 kg is falling under gravity in a viscous medium. The drag force on it is given by 0.5u, where u is the instantaneous speed. If upthrust force on it is 5 N, then terminal speed (in m/s) is (take g=10 ms−2)