50278 + Interview Questions in Physics

1.	The mass density of the material of a T joint is 2 kg/m. The dimensions of this joint are shown in the figure. What is the approximate moment of inertia (MI) of the T joint about an axis passing through their common joining point and perpendicular to the plane of structure?
Answer» The mass density of the material of a $T$ joint is $2 kg/m$ . The dimensions of this joint are shown in the figure. What is the approximate moment of inertia ( $MI$ ) of the $T$ joint about an axis passing through their common joining point and perpendicular to the plane of structure?

Discussion

2.	The diagram shows the change x in length of a thin uniform wire caused by the application of stress F, at two different temperatures T1 and T2. The variations shown suggest that:
Answer» The diagram shows the change x in length of a thin uniform wire caused by the application of stress F, at two different temperatures $T_{1}$ and $T_{2}$ . The variations shown suggest that:

2.

The diagram shows the change x in length of a thin uniform wire caused by the application of stress F, at two different temperatures T1 and T2. The variations shown suggest that:

Answer»

The diagram shows the change x in length of a thin uniform wire caused by the application of stress F, at two different temperatures $T_{1}$ and $T_{2}$ . The variations shown suggest that:

Discussion

3.	The work function of a photoelectric material is 4.0 eV. What is the threshold wavelength?
Answer» The work function of a photoelectric material is 4.0 eV. What is the threshold wavelength?

Discussion

4.	An athlete completes one round of a circular track of radius R in 30 sec. What will be the magnitude of displacement at the end of 2 min 30 sec?
Answer» An athlete completes one round of a circular track of radius $R$ in $30$ sec. What will be the magnitude of displacement at the end of $2$ min $30$ sec?

Discussion

5.	A car of mass 50 kg is travelling at a speed of 20 m/s on a circular road of radius 30 m having angle of banking equal to 53∘. If the coefficient of static friction between the road and the tyres is 0.4, then find the value of frictional force acting on the car. Take g=10 m/s2.
Answer» A car of mass $50 kg$ is travelling at a speed of $20 m/s$ on a circular road of radius $30 m$ having angle of banking equal to $53^{\circ}$ . If the coefficient of static friction between the road and the tyres is $0.4$ , then find the value of frictional force acting on the car. Take $g = 10 {m/s}^{2}$ .

Discussion

6.	The image for the converging beam after refraction through the curved surface is formed at :
Answer» The image for the converging beam after refraction through the curved surface is formed at :

Discussion

7.	A steel ball initially at a pressure of 1.0×105 Pa is heated from 20∘ C to 120∘ C keeping its volume constant. Find the pressure inside the ball. Coefficient of linear expansion of steel =12×10−6 ∘C−1 and bulk modulus of steel =1.6×1011Nm−2.
Answer» A steel ball initially at a pressure of $1.0 \times 10^{5}$ Pa is heated from $20^{\circ} C$ to $120^{\circ} C$ keeping its volume constant. Find the pressure inside the ball. Coefficient of linear expansion of steel $= 12 \times 10^{- 6}^{\circ} C^{- 1}$ and bulk modulus of steel $= 1.6 \times 10^{11} N m^{- 2}$ .

7.

A steel ball initially at a pressure of 1.0×105 Pa is heated from 20∘ C to 120∘ C keeping its volume constant. Find the pressure inside the ball. Coefficient of linear expansion of steel =12×10−6 ∘C−1 and bulk modulus of steel =1.6×1011Nm−2.

Answer»

A steel ball initially at a pressure of $1.0 \times 10^{5}$ Pa is heated from $20^{\circ} C$ to $120^{\circ} C$ keeping its volume constant.

Find the pressure inside the ball. Coefficient of linear expansion of steel $= 12 \times 10^{- 6}^{\circ} C^{- 1}$ and bulk modulus of steel $= 1.6 \times 10^{11} N m^{- 2}$ .

Discussion

8.	P−V diagram of an ideal gas is shown in the figure. Work done by the gas in process ABCD is
Answer» $P - V$ diagram of an ideal gas is shown in the figure. Work done by the gas in process $A B C D$ is

Discussion

9.	Assume air in the atmosphere is replaced by water of uniform density such that the pressure is unchanged on the Earth's surface. i.e. 105 Pa. If a square plate of thickness 2 mm is kept on the surface of Earth and the effort required to lift it slowly is compared for both the cases (air and water), then choose the correct option?
Answer» Assume air in the atmosphere is replaced by water of uniform density such that the pressure is unchanged on the Earth's surface. i.e. 10⁵ Pa. If a square plate of thickness 2 mm is kept on the surface of Earth and the effort required to lift it slowly is compared for both the cases (air and water), then choose the correct option?

Discussion

10.	How much heat energy is released when 10 kg of water at 100∘ C is brought to its freezing point? (Specific heat of water =1 cal/g∘C)
Answer» How much heat energy is released when $10 kg$ of water at $100^{\circ} C$ is brought to its freezing point? (Specific heat of water $= 1 {cal/g}^{\circ} C$ )

Discussion

11.	A large plane charge sheet having surface charge density σ=2.0×10−6 Cm−2 lies in the x-y plane. Find the flux of the electric field through a circular area of radius 1 cm lying completely in the region where x, y, z are all positive and with its normal making an angle of 60∘ with the z-axis. (Given that the field due to infinite charged sheet is σ2ϵ0 where σ = surface charge density. Also note that it is perpendicular to the sheet and is constant for all points from the sheet.)
Answer» A large plane charge sheet having surface charge density $σ = 2.0 \times 10^{- 6} C m^{- 2}$ lies in the x-y plane. Find the flux of the electric field through a circular area of radius $1 c m$ lying completely in the region where x, y, z are all positive and with its normal making an angle of $60^{\circ}$ with the z-axis. (Given that the field due to infinite charged sheet is $\frac{σ}{2 ϵ_{0}}$ where $σ$ = surface charge density. Also note that it is perpendicular to the sheet and is constant for all points from the sheet.)

Discussion

12.	A particle ís executing simple harmonic motion with amplitude of 0.1 m. At a certain instant when its displacement is 0.02 m, its acceleration is 0.5 ms−2. The maximum velocity of the particle is (in ms−1)
Answer» A particle ís executing simple harmonic motion with amplitude of $0.1 m$ . At a certain instant when its displacement is $0.02 m$ , its acceleration is $0.5 {ms}^{- 2}$ . The maximum velocity of the particle is (in ${ms}^{- 1}$ )

Discussion

13.	The time taken by an engine of power 10 kW to lift a mass of 200 kg to a height of 40 m is (g=10 ms−2)
Answer» The time taken by an engine of power $10 kW$ to lift a mass of $200 kg$ to a height of $40 m$ is $(g = 10 m s^{- 2})$

Discussion

14.	Which factor provide a centripetal force in the following cases: i) revolution of electron around the nucleus. ii) revolution of earth around the sun. iii) circular motion of a cyclist.
Answer» Which factor provide a centripetal force in the following cases: i) revolution of electron around the nucleus. ii) revolution of earth around the sun. iii) circular motion of a cyclist.

Discussion

15.	The position vector of four identical masses of mass 1 kg each are →r1=(^i+2^j+7^k),→r2=(3^i+5^j+^k), →r3=(6^i+2^j+3^k) and →r4=(2^i−^j+5^k). Find the position vector of their centre of mass.
Answer» The position vector of four identical masses of mass $1 kg$ each are $_{1} = (^i + 2^j + 7^k),_{2} = (3^i + 5^j +^k),$ $_{3} = (6^i + 2^j + 3^k)$ and $_{4} = (2^i -^j + 5^k)$ . Find the position vector of their centre of mass.

Discussion

16.	A uniform ring of mass m is lying at a distance 1.73 a from the centre of a sphere of mass M just over the sphere where a is the small radius of the ring as well as that of the sphere. Then gravitational force exerted is
Answer» A uniform ring of mass m is lying at a distance 1.73 a from the centre of a sphere of mass M just over the sphere where a is the small radius of the ring as well as that of the sphere. Then gravitational force exerted is

16.

A uniform ring of mass m is lying at a distance 1.73 a from the centre of a sphere of mass M just over the sphere where a is the small radius of the ring as well as that of the sphere. Then gravitational force exerted is

Answer»

A uniform ring of mass m is lying at a distance 1.73 a from the centre of a sphere of mass M just over the sphere where a is the small radius of the ring as well as that of the sphere. Then gravitational

force exerted is

Discussion

17.	A series L-C-R circuit with R = 120 Ω has an angular frequency of 4×105 rad/sec. At resonance, voltages across resistance and inductor are 60 V and 40 V respectively. If frequency at which the circuit current lags behind the voltage by a phase of π/4 radian is k × 105 rad/sec, then the value of k is (answer upto two decimal places)
Answer» A series L-C-R circuit with R = 120 $Ω$ has an angular frequency of $4 \times 10^{5}$ rad/sec. At resonance, voltages across resistance and inductor are 60 $V$ and 40 $V$ respectively. If frequency at which the circuit current lags behind the voltage by a phase of π/4 radian is $k \times 10^{5}$ rad/sec, then the value of $k$ is (answer upto two decimal places)

Discussion

18.	The potential energy (in SI units) of a particle of mass 2 kg in a conservative field is U=6x−8y. If the initial velocity of the particle is →u=−1.5^i+2^j m/s, then the total distance travelled by the particle in first two seconds is
Answer» The potential energy (in SI units) of a particle of mass $2 kg$ in a conservative field is $U = 6 x - 8 y$ . If the initial velocity of the particle is $\to u = - 1.5^i + 2^j m/s,$ then the total distance travelled by the particle in first two seconds is

Discussion

19.	If the speed of the particle is v=8t3−3t2+2 m/s, the distance of the particle as a function of time t and the average speed in 2 sec respectively are
Answer» If the speed of the particle is $v = 8 t^{3} - 3 t^{2} + 2 m/s$ , the distance of the particle as a function of time $t$ and the average speed in $2 sec$ respectively are

Discussion

20.	If a force →F =(7 ^i−6 ^j+2 ^k) N and velocity →v=(6 ^i+^k) m/s, then the instantaneous power is
Answer» If a force $\to F = (7^i - 6^j + 2^k) N$ and velocity $\to v = (6^i +^k) m/s,$ then the instantaneous power is

Discussion

21.	A baobaln rises from rest with a constant acceleration 9/8. A stins is released from it when it has risen to height h. The time taken by the stone to reach the ground is?
Answer» A baobaln rises from rest with a constant acceleration 9/8. A stins is released from it when it has risen to height h. The time taken by the stone to reach the ground is?

Discussion

22.	Which of the following relations correctly shows the value of current amplification factor at a constant collector-emitter voltage?
Answer» Which of the following relations correctly shows the value of current amplification factor at a constant collector-emitter voltage?

Discussion

23.	q1,q2,q3 and q4 are point charges located at points as shown in the figure and S is spherical Gaussian surface of radius R. Which of the following is true according to the Gauss’s law.
Answer» $q_{1}, q_{2}, q_{3} a n d q_{4}$ are point charges located at points as shown in the figure and S is spherical Gaussian surface of radius R. Which of the following is true according to the Gauss’s law.

Discussion

24.	The rod is slipping. Velocity and acceleration of one end of rod are given. Find the angular speed and the acceleration of corner P.
Answer» The rod is slipping. Velocity and acceleration of one end of rod are given. Find the angular speed and the acceleration of corner P.

24.

The rod is slipping. Velocity and acceleration of one end of rod are given. Find the angular speed and the acceleration of corner P.

Answer»

The rod is slipping. Velocity and acceleration of one end of rod are given. Find the angular speed and the acceleration of corner P.

Discussion

25.	Photoelectric emission is observed from a metallic surface for frequencies v1 and v2 of the incident light rays (v1) > (v2). If the maximum values of kinetic energy of the photoelectrons emitted in the two cases are in the ratio of 1 : k, then the threshold frequency of the metallic surface is
Answer» Photoelectric emission is observed from a metallic surface for frequencies $v_{1}$ and $v_{2}$ of the incident light rays $(v_{1})$ > $(v_{2})$ . If the maximum values of kinetic energy of the photoelectrons emitted in the two cases are in the ratio of 1 : k, then the threshold frequency of the metallic surface is

Discussion

26.	P.E -GMm/R+h but the formula is mgh!!
Answer» P.E -GMm/R+h but the formula is mgh!!

Discussion

27.	Derivation for energy conservation in SHM.WITH EACH AND EVERY CLEAR STEPS
Answer» Derivation for energy conservation in SHM.WITH EACH AND EVERY CLEAR STEPS

Discussion

28.	The electric field maintained inside a conductor is 10N/C and they drift with a speed of 5×10−4m/s What is the relaxation time for the electrons?
Answer» The electric field maintained inside a conductor is 10N/C and they drift with a speed of $5 \times 10^{- 4} m / s$ What is the relaxation time for the electrons?

Discussion

29.	A wave is travelling from heavier string to a lighter. If the ratio of wavelength of incident to transmitted wave is 1:4, then the ratio of the linear mass density of heavier string to the lighter string is
Answer» A wave is travelling from heavier string to a lighter. If the ratio of wavelength of incident to transmitted wave is $1 : 4$ , then the ratio of the linear mass density of heavier string to the lighter string is

Discussion

30.	The meter is defined as the distance traveled by light in 1/299792458 seconds? why didn't people choose some easier number than 1/300000000 seconds? why not 1 second?
Answer» The meter is defined as the distance traveled by light in 1/299792458 seconds? why didn't people choose some easier number than 1/300000000 seconds? why not 1 second?

Discussion

31.	Starting from rest a particle moves in a straight line, whose acceleration varies with time as a=(29−t2)12 m/s2 for 0≤t≤5s a=3π8 m/s2 for t>5s The velocity of the particle at t=7s is :
Answer» Starting from rest a particle moves in a straight line, whose acceleration varies with time as $a = (29 - t^{2})^{\frac{1}{2}} {m/s}^{2}$ for $0 \leq t \leq 5 s$ $a = \frac{3 π}{8} {m/s}^{2}$ for $t > 5 s$ The velocity of the particle at $t = 7 s$ is :

Discussion

32.	In a thick glass slab of thickness l, and refractive index n1, a cuboidal cavity of thickness ‘m’ is carved as shown in the figure and is filled with a liquid of refractive index n2(n1>n2). The ratio lm, so that shift produced by this slab is zero when an observer A observes an object B with paraxial rays is
Answer» In a thick glass slab of thickness $l$ , and refractive index $n_{1}$ , a cuboidal cavity of thickness ‘m’ is carved as shown in the figure and is filled with a liquid of refractive index $n_{2} (n_{1} > n_{2})$ . The ratio $\frac{l}{m}$ , so that shift produced by this slab is zero when an observer $A$ observes an object $B$ with paraxial rays is

Discussion

33.	A body of mass m is thrown upwards at an angle θ with the horizontal with velocity v. While rising up the velocity of the mass after t seconds will be
Answer» A body of mass m is thrown upwards at an angle $θ$ with the horizontal with velocity v. While rising up the velocity of the mass after t seconds will be

Discussion

34.	A metallic block of density 5 gm cm−3 and having dimensions 5 cm × 5 cm × 5 cm is weighed in water. Its apparent weight will be
Answer» A metallic block of density 5 gm $c m^{- 3}$ and having dimensions 5 cm $\times$ 5 cm $\times$ 5 cm is weighed in water. Its apparent weight will be

Discussion

35.	If a small plane circular coil with radius r with number of turns is placed at a distance Ã"â‚¬ËœdÃ"â‚¬â„" from a straight vertical conductor in the same plane as of coil. What will be the mutual induction between the two?
Answer» If a small plane circular coil with radius r with number of turns is placed at a distance Ã"â‚¬ËœdÃ"â‚¬â„" from a straight vertical conductor in the same plane as of coil. What will be the mutual induction between the two?

Discussion

36.	The value of that is magnetic permeability of free sapce is
Answer» The value of that is magnetic permeability of free sapce is

Discussion

37.	A rectangular loop carrying a current i is situated near a long straight wire such that the wire is parallel to one of the sides of the loop. If a steady current I is established in the wire, as shown in Fig., the loop
Answer» A rectangular loop carrying a current i is situated near a long straight wire such that the wire is parallel to one of the sides of the loop. If a steady current I is established in the wire, as shown in Fig., the loop

Discussion

38.	An electron is sent in an electric field of intensity 106 V/m. If the weight of electron is negligible, its acceleration will be
Answer» An electron is sent in an electric field of intensity $10^{6}$ V/m. If the weight of electron is negligible, its acceleration will be

Discussion

39.	An ideal gas is expanded isothermally from a volume V1 to volume V2 and then compressed adiabatically to original volume V1. The initial pressure is P1 and the final pressure iss P3. If the net work done is W, then
Answer» An ideal gas is expanded isothermally from a volume $V_{1}$ to volume $V_{2}$ and then compressed adiabatically to original volume $V_{1}$ . The initial pressure is $P_{1}$ and the final pressure iss $P_{3}$ . If the net work done is W, then

Discussion

40.	Two ships are 10 km apart on a line joining south to north. The one farther north is steaming west at 20 km h−1. The other is steaming north at 20 km h−1. What is their distance of closest approach? How long do they take to reach it?
Answer» Two ships are 10 km apart on a line joining south to north. The one farther north is steaming west at $20 {km h}^{- 1}$ . The other is steaming north at $20 {km h}^{- 1}$ . What is their distance of closest approach? How long do they take to reach it?

Discussion

41.	According to the principle of conservation of charge
Answer» According to the principle of conservation of charge

Discussion

42.	A stone thrown upward with a speed u from the top of the tower reaches the ground with a speed 3u. The height of the tower is
Answer» A stone thrown upward with a speed $u$ from the top of the tower reaches the ground with a speed $3 u$ . The height of the tower is

Discussion

43.	If vibrations of a string are to be increased by a factor of two, then tension in the string must be made [AIIMS 1999; Pb. PET 2000]
Answer» If vibrations of a string are to be increased by a factor of two, then tension in the string must be made [AIIMS 1999; Pb. PET 2000]

43.

If vibrations of a string are to be increased by a factor of two, then tension in the string must be made [AIIMS 1999; Pb. PET 2000]

Answer»

If vibrations of a string are to be increased by a factor of two, then tension in

the string must be made

[AIIMS 1999; Pb. PET 2000]

Discussion

44.	Two small balls A and B, each of mass m, are attached rigidly to the ends of a light rod of length d. The structure rotates about the perpendicular bisector of the rod at an angular speed ω. Calculate the angular momentum of the system about the axis of rotation
Answer» Two small balls $A$ and $B$ , each of mass $m$ , are attached rigidly to the ends of a light rod of length $d$ . The structure rotates about the perpendicular bisector of the rod at an angular speed $ω$ . Calculate the angular momentum of the system about the axis of rotation

44.

Two small balls A and B, each of mass m, are attached rigidly to the ends of a light rod of length d. The structure rotates about the perpendicular bisector of the rod at an angular speed ω. Calculate the angular momentum of the system about the axis of rotation

Answer»

Two small balls $A$ and $B$ , each of mass $m$ , are attached rigidly to the ends of a light rod of length $d$ . The structure rotates about the perpendicular bisector of the rod at an angular speed $ω$ . Calculate the angular momentum of the system about the axis of rotation

Discussion

45.	In the given figure, m1=200 g, m2=600 g,μ1=0.3, μ2=0.8 and K=200 N/m.The minimum force that must be applied on m1 to just displace m2 is (in N). (Take g = 10 m/ s2)
Answer» In the given figure, $m_{1} = 200 g,$ $m_{2} = 600 g,$ $μ_{1} = 0.3,$ $μ_{2} = 0.8$ $a n d K = 200 N / m .$ The minimum force that must be applied on $m_{1}$ to just displace $m_{2}$ is (in N). (Take g = 10 m/ $s^{2}$ )

Discussion

46.	If two waves having amplitudes 2A and A and same frequency and velocity, propagate in the same direction in the same phase, the resulting amplitude will be [MP PET 1991; DPMT 1999]
Answer» If two waves having amplitudes 2A and A and same frequency and velocity, propagate in the same direction in the same phase, the resulting amplitude will be [MP PET 1991; DPMT 1999]

46.

If two waves having amplitudes 2A and A and same frequency and velocity, propagate in the same direction in the same phase, the resulting amplitude will be [MP PET 1991; DPMT 1999]

Answer»

If two waves having amplitudes 2A and A and same frequency and velocity, propagate in the same direction in the same phase, the resulting amplitude will be

[MP PET 1991; DPMT 1999]

Discussion

47.	A bomber plane moves horizontally with a speed of 500 m/s and a bomb released from it, strikes the ground in 10 sec. Angle at which it strikes the ground will be (g=10 m/s2)
Answer» A bomber plane moves horizontally with a speed of 500 m/s and a bomb released from it, strikes the ground in 10 sec. Angle at which it strikes the ground will be $(g = 10 m / s^{2})$

Discussion

48.	If a bullet of mass 5 gm moving with velocity 100 m/sec, penetrates the wooden block upto 6 cm. Then the average force imposed by the bullet on the block is
Answer» If a bullet of mass 5 gm moving with velocity 100 m/sec, penetrates the wooden block upto 6 cm. Then the average force imposed by the bullet on the block is

Discussion

49.	The displacement vs time graph for two waves A and B which travel along the same string are shown in the figure. Their intensity ratio IAIB is
Answer» The displacement vs time graph for two waves A and B which travel along the same string are shown in the figure. Their intensity ratio $\frac{I_{A}}{I_{B}}$ is

49.

The displacement vs time graph for two waves A and B which travel along the same string are shown in the figure. Their intensity ratio IAIB is

Answer»

The displacement vs time graph for two waves A and B which travel along the same string are shown in the figure. Their intensity ratio $\frac{I_{A}}{I_{B}}$ is

Discussion

50.	A block of mass 5 kg tied at the end of a string is whirled round in a vertical circle of radius 1 m. The critical speed of the block at the top of its swing below which the string would slacken before the block reaches the top is Take (g = 10 m/s2)
Answer» A block of mass $5 kg$ tied at the end of a string is whirled round in a vertical circle of radius $1 m$ . The critical speed of the block at the top of its swing below which the string would slacken before the block reaches the top is Take $(g = 10 {m/s}^{2})$

Discussion

Explore topic-wise InterviewSolutions in Current Affairs.

The mass density of the material of a T joint is 2 kg/m. The dimensions of this joint are shown in the figure. What is the approximate moment of inertia (MI) of the T joint about an axis passing through their common joining point and perpendicular to the plane of structure?

The diagram shows the change x in length of a thin uniform wire caused by the application of stress F, at two different temperatures T1 and T2. The variations shown suggest that:

The work function of a photoelectric material is 4.0 eV. What is the threshold wavelength?

An athlete completes one round of a circular track of radius R in 30 sec. What will be the magnitude of displacement at the end of 2 min 30 sec?

A car of mass 50 kg is travelling at a speed of 20 m/s on a circular road of radius 30 m having angle of banking equal to 53∘. If the coefficient of static friction between the road and the tyres is 0.4, then find the value of frictional force acting on the car. Take g=10 m/s2.

The image for the converging beam after refraction through the curved surface is formed at :

A steel ball initially at a pressure of 1.0×105 Pa is heated from 20∘ C to 120∘ C keeping its volume constant. Find the pressure inside the ball. Coefficient of linear expansion of steel =12×10−6 ∘C−1 and bulk modulus of steel =1.6×1011Nm−2.

P−V diagram of an ideal gas is shown in the figure. Work done by the gas in process ABCD is

How much heat energy is released when 10 kg of water at 100∘ C is brought to its freezing point? (Specific heat of water =1 cal/g∘C)

A particle ís executing simple harmonic motion with amplitude of 0.1 m. At a certain instant when its displacement is 0.02 m, its acceleration is 0.5 ms−2. The maximum velocity of the particle is (in ms−1)

The time taken by an engine of power 10 kW to lift a mass of 200 kg to a height of 40 m is (g=10 ms−2)

Which factor provide a centripetal force in the following cases: i) revolution of electron around the nucleus. ii) revolution of earth around the sun. iii) circular motion of a cyclist.

The position vector of four identical masses of mass 1 kg each are →r1=(^i+2^j+7^k),→r2=(3^i+5^j+^k), →r3=(6^i+2^j+3^k) and →r4=(2^i−^j+5^k). Find the position vector of their centre of mass.

A uniform ring of mass m is lying at a distance 1.73 a from the centre of a sphere of mass M just over the sphere where a is the small radius of the ring as well as that of the sphere. Then gravitational force exerted is

The potential energy (in SI units) of a particle of mass 2 kg in a conservative field is U=6x−8y. If the initial velocity of the particle is →u=−1.5^i+2^j m/s, then the total distance travelled by the particle in first two seconds is

If the speed of the particle is v=8t3−3t2+2 m/s, the distance of the particle as a function of time t and the average speed in 2 sec respectively are

If a force →F =(7 ^i−6 ^j+2 ^k) N and velocity →v=(6 ^i+^k) m/s, then the instantaneous power is

A baobaln rises from rest with a constant acceleration 9/8. A stins is released from it when it has risen to height h. The time taken by the stone to reach the ground is?

Which of the following relations correctly shows the value of current amplification factor at a constant collector-emitter voltage?

q1,q2,q3 and q4 are point charges located at points as shown in the figure and S is spherical Gaussian surface of radius R. Which of the following is true according to the Gauss’s law.

The rod is slipping. Velocity and acceleration of one end of rod are given. Find the angular speed and the acceleration of corner P.

Photoelectric emission is observed from a metallic surface for frequencies v1 and v2 of the incident light rays (v1) &gt; (v2). If the maximum values of kinetic energy of the photoelectrons emitted in the two cases are in the ratio of 1 : k, then the threshold frequency of the metallic surface is

P.E -GMm/R+h but the formula is mgh!! ​

Derivation for energy conservation in SHM.WITH EACH AND EVERY CLEAR STEPS

The electric field maintained inside a conductor is 10N/C and they drift with a speed of 5×10−4m/s What is the relaxation time for the electrons?

A wave is travelling from heavier string to a lighter. If the ratio of wavelength of incident to transmitted wave is 1:4, then the ratio of the linear mass density of heavier string to the lighter string is

The meter is defined as the distance traveled by light in 1/299792458 seconds? why didn't people choose some easier number than 1/300000000 seconds? why not 1 second?

Starting from rest a particle moves in a straight line, whose acceleration varies with time as a=(29−t2)12 m/s2 for 0≤t≤5s a=3π8 m/s2 for t&gt;5s The velocity of the particle at t=7s is :

A body of mass m is thrown upwards at an angle θ with the horizontal with velocity v. While rising up the velocity of the mass after t seconds will be

A metallic block of density 5 gm cm−3 and having dimensions 5 cm × 5 cm × 5 cm is weighed in water. Its apparent weight will be

If a small plane circular coil with radius r with number of turns is placed at a distance Ã"â‚¬ËœdÃ"â‚¬â„" from a straight vertical conductor in the same plane as of coil. What will be the mutual induction between the two?

The value of that is magnetic permeability of free sapce is

A rectangular loop carrying a current i is situated near a long straight wire such that the wire is parallel to one of the sides of the loop. If a steady current I is established in the wire, as shown in Fig., the loop

An electron is sent in an electric field of intensity 106 V/m. If the weight of electron is negligible, its acceleration will be

An ideal gas is expanded isothermally from a volume V1 to volume V2 and then compressed adiabatically to original volume V1. The initial pressure is P1 and the final pressure iss P3. If the net work done is W, then

Two ships are 10 km apart on a line joining south to north. The one farther north is steaming west at 20 km h−1. The other is steaming north at 20 km h−1. What is their distance of closest approach? How long do they take to reach it?

According to the principle of conservation of charge

A stone thrown upward with a speed u from the top of the tower reaches the ground with a speed 3u. The height of the tower is

If vibrations of a string are to be increased by a factor of two, then tension in the string must be made [AIIMS 1999; Pb. PET 2000]

Two small balls A and B, each of mass m, are attached rigidly to the ends of a light rod of length d. The structure rotates about the perpendicular bisector of the rod at an angular speed ω. Calculate the angular momentum of the system about the axis of rotation

In the given figure, m1=200 g, m2=600 g,μ1=0.3, μ2=0.8 and K=200 N/m.The minimum force that must be applied on m1 to just displace m2 is (in N). (Take g = 10 m/ s2)

If two waves having amplitudes 2A and A and same frequency and velocity, propagate in the same direction in the same phase, the resulting amplitude will be [MP PET 1991; DPMT 1999]

A bomber plane moves horizontally with a speed of 500 m/s and a bomb released from it, strikes the ground in 10 sec. Angle at which it strikes the ground will be (g=10 m/s2)

If a bullet of mass 5 gm moving with velocity 100 m/sec, penetrates the wooden block upto 6 cm. Then the average force imposed by the bullet on the block is

The displacement vs time graph for two waves A and B which travel along the same string are shown in the figure. Their intensity ratio IAIB is

A block of mass 5 kg tied at the end of a string is whirled round in a vertical circle of radius 1 m. The critical speed of the block at the top of its swing below which the string would slacken before the block reaches the top is Take (g = 10 m/s2)

Photoelectric emission is observed from a metallic surface for frequencies v1 and v2 of the incident light rays (v1) > (v2). If the maximum values of kinetic energy of the photoelectrons emitted in the two cases are in the ratio of 1 : k, then the threshold frequency of the metallic surface is

P.E -GMm/R+h but the formula is mgh!!

Starting from rest a particle moves in a straight line, whose acceleration varies with time as a=(29−t2)12 m/s2 for 0≤t≤5s a=3π8 m/s2 for t>5s The velocity of the particle at t=7s is :