50278 + Interview Questions in Physics Page 54 InterviewSolution

2651.	An uninflates balloon has mass m.When it is inflated by blowing air of mass M into it.Its net weight will be
Answer» An uninflates balloon has mass m.When it is inflated by blowing air of mass M into it.Its net weight will be

Discussion

2652.	the angle between the vectors (icap+jcap) and (jcap+kcap) is?
Answer» the angle between the vectors (icap+jcap) and (jcap+kcap) is?

Discussion

2653.	Y = 4X2 how to find acceleration of the particle
Answer» Y = 4X2 how to find acceleration of the particle

Discussion

2654.	A stone thrown upward with a speed u from the top of the tower reaches the ground with a velocity 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 velocity $3 u$ . The height of the tower is

Discussion

2655.	If u=exsinx and v=excosx, then which of the following is/are true?
Answer» If $u = e^{x} sin x$ and $v = e^{x} cos x$ , then which of the following is/are true?

Discussion

2656.	nt25 tuning forks are arranged in series in the order of decreasing frequency. Any two successive forks produce 3 beats/sec. If the frequency of the first tuning fork is the octave of the last fork,then the frequency of the 21st fork isn nta)72 Hzn ntb)288 Hzn ntc)84 Hzn ntd)87 Hzn
Answer» nt25 tuning forks are arranged in series in the order of decreasing frequency. Any two successive forks produce 3 beats/sec. If the frequency of the first tuning fork is the octave of the last fork,then the frequency of the 21st fork isn nta)72 Hzn ntb)288 Hzn ntc)84 Hzn ntd)87 Hzn

Discussion

2657.	A closed tube filled with water is rotating as shown in figure. The pressure difference PA−PC is
Answer» A closed tube filled with water is rotating as shown in figure. The pressure difference $P_{A} - P_{C}$ is

Discussion

2658.	A physical quantity X is related to four measurable quantities a, b, c and d as follows X=a2b3c5/2d−2 The percentage error in the measurement of a, b, c and d are 1%,2%,2% and 4% respectively. What is the percentage error in quantity X?
Answer» A physical quantity X is related to four measurable quantities a, b, c and d as follows $X = a^{2} b^{3} c^{5 / 2} d^{- 2}$ The percentage error in the measurement of a, b, c and d are $1 %, 2 %, 2 %$ and $4 %$ respectively. What is the percentage error in quantity X?

Discussion

2659.	A charged conducting sphere of radius 1.3m has uniform surface charge density 50.0μ Cm^{-2}. The charge on the sphere is (1) 1.06×10^{-3 } C (2) 2.12×10^{-4} C (3) 0.50×10^{-3} C (4) 3.0×10^{-3} C
Answer» A charged conducting sphere of radius 1.3m has uniform surface charge density 50.0μ Cm^{-2}. The charge on the sphere is (1) 1.06×10^{-3 } C (2) 2.12×10^{-4} C (3) 0.50×10^{-3} C (4) 3.0×10^{-3} C

Discussion

2660.	When √3 A current is passes through a tangent galvanometer, there is a deflection of 30∘ in it. The deflection obtained when 3 A current passing through it-
Answer» When $\sqrt{3} A$ current is passes through a tangent galvanometer, there is a deflection of $30^{\circ}$ in it. The deflection obtained when $3 A$ current passing through it-

Discussion

2661.	3.A disc of mass M kg and radius R metre is rotating at an angular speed of w rad/s when the motor is switched off. Neglecting the friction at the axle, the force that must be applied tangentially to the wheel to bring it to rest in time t is
Answer» 3.A disc of mass M kg and radius R metre is rotating at an angular speed of w rad/s when the motor is switched off. Neglecting the friction at the axle, the force that must be applied tangentially to the wheel to bring it to rest in time t is

Discussion

2662.	A block of mass m kg is attached to a massless spring of spring constant k N/m. This system is accelerated upwards with an acceleration a m/s2. Then the elongation in spring will be (in metres):
Answer» A block of mass $m kg$ is attached to a massless spring of spring constant $k N/m$ . This system is accelerated upwards with an acceleration $a {m/s}^{2}$ . Then the elongation in spring will be (in metres):

Discussion

2663.	locate the centre of mass of one quarter of risk of radius R.
Answer» locate the centre of mass of one quarter of risk of radius R.

Discussion

2664.	Two blocks each of mass M are connected to the ends of a light frame as shown in below figure. The frame is rotated about the vertical line of symmetry. The rod breaks if the tension in it exceeds T0. Find the maximum frequency with which the frame may be rotated without breaking the rod.
Answer» Two blocks each of mass M are connected to the ends of a light frame as shown in below figure. The frame is rotated about the vertical line of symmetry. The rod breaks if the tension in it exceeds $T_{0}$ . Find the maximum frequency with which the frame may be rotated without breaking the rod.

Discussion

2665.	Initially, the nucleus of Radium−226 is at rest. It decays by emitting an α− particle, and thus the nucleus of Radon is created. The released energy during the decay is 4.87 MeV, which appears as the kinetic energy of the two resulted particles. The kinetic energy of α− particle & Radon nucleus are respectively.[mα=4.002 u, mRn=222.017 u]
Answer» Initially, the nucleus of $Radium - 226$ is at rest. It decays by emitting an $α -$ particle, and thus the nucleus of $Radon$ is created. The released energy during the decay is $4.87 MeV$ , which appears as the kinetic energy of the two resulted particles. The kinetic energy of $α -$ particle & $Radon$ nucleus are respectively. $[m_{α} = 4.002 u, m_{Rn} = 222.017 u]$

Discussion

2666.	why ZnO is yellow when hot and white whn cold?
Answer» why ZnO is yellow when hot and white whn cold?

Discussion

2667.	If x and R stands for distance, then which of the following is dimensionally same as ∫Rdxx2?
Answer» If $x$ and $R$ stands for distance, then which of the following is dimensionally same as $\int \frac{R d x}{x^{2}}$ ?

Discussion

2668.	What is chromatic aberration?
Answer» What is chromatic aberration?

Discussion

2669.	Find the gravitational potential energy of a system of four particles, each having mass m, placed at the vertices of a square of side l at the centre of the square.
Answer» Find the gravitational potential energy of a system of four particles, each having mass m, placed at the vertices of a square of side l at the centre of the square.

Discussion

2670.	A point charge of 2.0 μC is at the centre of a cubic Gaussian surface 9.0 cm on edge. What is the net electric flux through the surface?
Answer» A point charge of 2.0 $μ$ C is at the centre of a cubic Gaussian surface 9.0 cm on edge. What is the net electric flux through the surface?

Discussion

2671.	A thin prism is made of a material having refractive indices 1.61 and 1.65 for red and violet lights, respectively. The dispersive power of the material is 0.07. It is found that a beam of yellow light passing through the prism suffers a minimum deviation of 4∘ in favourable conditions. The angle of prism is θ∘. The value of theta is (integer only)
Answer» A thin prism is made of a material having refractive indices $1.61$ and $1.65$ for red and violet lights, respectively. The dispersive power of the material is $0.07.$ It is found that a beam of yellow light passing through the prism suffers a minimum deviation of $4^{\circ}$ in favourable conditions. The angle of prism is $θ^{\circ}$ . The value of $t h e t a$ is (integer only)

Discussion

2672.	A particle moves along a circle of radius (20π m) with constant tangential acceleration. If the velocity of the particle is 80 m/s at the end of the second revolution after motion has begun, the tangential acceleration is
Answer» A particle moves along a circle of radius $(\frac{20}{π} m)$ with constant tangential acceleration. If the velocity of the particle is $80 m / s$ at the end of the second revolution after motion has begun, the tangential acceleration is

Discussion

2673.	emf of the cell cu/cu2+(1M)//ag+(0.1)/ag is x volt if concentration of anode and cathode are interchangedthen emf of cell becomes y so is x
Answer» emf of the cell cu/cu2+(1M)//ag+(0.1)/ag is x volt if concentration of anode and cathode are interchangedthen emf of cell becomes y so is x

Discussion

2674.	A thin rod of mass m and lengthfrom one of its ends. It is set into oscillation abouta horizontal axis. Its angular speed is o whilepassing through its mean position. How high will itscentre of mass rise from its lowest position?suspended
Answer» A thin rod of mass m and lengthfrom one of its ends. It is set into oscillation abouta horizontal axis. Its angular speed is o whilepassing through its mean position. How high will itscentre of mass rise from its lowest position?suspended

Discussion

2675.	A body of mass 100 g has a kinetic energy of 5 J. Find its linear momentum.
Answer» A body of mass $100 g$ has a kinetic energy of $5 J$ . Find its linear momentum.

Discussion

2676.	why do gases heat up when they expand above their inversion temperature?
Answer» why do gases heat up when they expand above their inversion temperature?

Discussion

2677.	What is enthalpy of a reaction?.
Answer» What is enthalpy of a reaction?.

Discussion

2678.	The variation of potential V with distance r from a fixed point is shown in the figure. The magnitude of electric field at r=2 cm is
Answer» The variation of potential $V$ with distance $r$ from a fixed point is shown in the figure. The magnitude of electric field at $r = 2 cm$ is

Discussion

2679.	A parallel plate capacitor is made by stacking n equally spaced plates connected alternatively. If the capacitance between any two adjacent plates is C, then the resultant capacitance is
Answer» A parallel plate capacitor is made by stacking $n$ equally spaced plates connected alternatively. If the capacitance between any two adjacent plates is $C$ , then the resultant capacitance is

Discussion

2680.	1 mole of an ideal gas at initial temperature of T K does 6R joules of work adiabatically. If the ratio of specific heats of this gas at constant pressure and at constant volume is 53, then final temperature of the gas will be
Answer» $1$ mole of an ideal gas at initial temperature of $T K$ does $6 R$ joules of work adiabatically. If the ratio of specific heats of this gas at constant pressure and at constant volume is $\frac{5}{3},$ then final temperature of the gas will be

Discussion

2681.	A circular cylinder of mass m and radius r is connected by a spring of stiffness k on an inclined plane as shown in the figure below. If it is free to roll on the rough surface which is horizontal without slipping, then its natural frequency is
Answer» A circular cylinder of mass m and radius r is connected by a spring of stiffness k on an inclined plane as shown in the figure below. If it is free to roll on the rough surface which is horizontal without slipping, then its natural frequency is

Discussion

2682.	15.Two rods of equal lengths (l) and equal mass M are kept along x and y axis respectively such that their centre of mass lie at origin. The moment of inertia about a line y=x is
Answer» 15.Two rods of equal lengths (l) and equal mass M are kept along x and y axis respectively such that their centre of mass lie at origin. The moment of inertia about a line y=x is

Discussion

2683.	A liquid at 30oC is poured very slowly into a Calorimeter that is at temperature of 110oC. The boiling temperature of the liquid is 80oC. It is found that the first 5gm of the liquid completely evaporates. After pouring another 80 gm of the liquid the equilibrium temperature is found to be 50oC. The ratio of the Latent heat of the liquid to its specific heat will be∘C. (Neglect the heat exchange with surrounding)
Answer» A liquid at $30^{o}$ C is poured very slowly into a Calorimeter that is at temperature of $110^{o}$ C. The boiling temperature of the liquid is $80^{o}$ C. It is found that the first $5$ gm of the liquid completely evaporates. After pouring another $80$ gm of the liquid the equilibrium temperature is found to be $50^{o}$ C. The ratio of the Latent heat of the liquid to its specific heat will be $^{\circ} C$ . (Neglect the heat exchange with surrounding)

Discussion

2684.	A force shown in the F−x graph is applied to a 5 kg cart, which then climbs up a ramp as shown. The maximum height Ymax the cart can reach (in m) is
Answer» A force shown in the $F - x$ graph is applied to a $5 k g$ cart, which then climbs up a ramp as shown. The maximum height $Y_{m a x}$ the cart can reach (in $m$ ) is

Discussion

2685.	If the shortest wavelengths of the continuous spectrum coming out of a Coolidge tube is 0.1 ∘A, then the de Broglie wavelength of the electron reaching the target metal in the Coolidge tube is approximately (hc=12400 eV−∘A,h=6.63×10−34 in MKS system andmass of electron=9.1×10−31 kg)
Answer» If the shortest wavelengths of the continuous spectrum coming out of a Coolidge tube is $0.1 \circ A$ , then the de Broglie wavelength of the electron reaching the target metal in the Coolidge tube is approximately $(h c = 12400 e V - \circ A, h = 6.63 \times 10^{- 34} in MKS system and mass of electron = 9.1 \times 10^{- 31} kg)$

Discussion

2686.	parallel plate capacitor of area A and separation between plate d, charged with current I. What is the displacement current through a plane of surface A/4 parallel to the plate and symmetrically drawn between the plate?
Answer» parallel plate capacitor of area A and separation between plate d, charged with current I. What is the displacement current through a plane of surface A/4 parallel to the plate and symmetrically drawn between the plate?

Discussion

2687.	is particle is moving with a velocity V=3i+4j at an instant of time if a force F= 4i+6j+5K acts on the particle at that instant then the radius of curvature of the particle is (mass is 2kg)
Answer» is particle is moving with a velocity V=3i+4j at an instant of time if a force F= 4i+6j+5K acts on the particle at that instant then the radius of curvature of the particle is (mass is 2kg)

Discussion

2688.	The concept of limiting reagen
Answer» The concept of limiting reagen

Discussion

2689.	ntA planet of mass m moves around the sun of mass M in an elliptical orbit . The maximum and minimum distances of the planet from the sun are r1 and r2 respectively . The time period of the planet is proportional to ?n
Answer» ntA planet of mass m moves around the sun of mass M in an elliptical orbit . The maximum and minimum distances of the planet from the sun are r1 and r2 respectively . The time period of the planet is proportional to ?n

Discussion

2690.	a ball has been thrown vertically upward with initial velocity 20 m/s calculate distance and displacement at t is 3s
Answer» a ball has been thrown vertically upward with initial velocity 20 m/s calculate distance and displacement at t is 3s

Discussion

2691.	If a person has 3 of 10 rupees notes, 4 of 50 rupees notes and 2 of 100 rupees notes. How many ways can he give none or some notes to his friend Ram?
Answer» If a person has 3 of 10 rupees notes, 4 of 50 rupees notes and 2 of 100 rupees notes. How many ways can he give none or some notes to his friend Ram?

Discussion

2692.	In a U tube experiment, a column AB of water is balanced by a column CD of paraffin. The relative density of paraffin is
Answer» In a U tube experiment, a column $A B$ of water is balanced by a column $C D$ of paraffin. The relative density of paraffin is

Discussion

2693.	Which of the following correctly represent schematically, the wave pattern produced by superposition of two waves of frequencies 9 Hz and 11 Hz is
Answer» Which of the following correctly represent schematically, the wave pattern produced by superposition of two waves of frequencies $9 Hz$ and $11 Hz$ is

Discussion

2694.	16. Why we take change in internal energy in isothermal process as zero?
Answer» 16. Why we take change in internal energy in isothermal process as zero?

Discussion

2695.	A helicopter is moving to the right at a constant horizontal velocity. It experiences three forces →Fgravitational,→Fdrag and force on it caused by rotor i.e. →Frotor. Which of the following diagrams can be correct free body diagram representing forces on the helicopter?
Answer» A helicopter is moving to the right at a constant horizontal velocity. It experiences three forces ${\to F}_{g r a v i t a t i o n a l}, {\to F}_{d r a g}$ and force on it caused by rotor i.e. ${\to F}_{r o t o r}$ . Which of the following diagrams can be correct free body diagram representing forces on the helicopter?

2695.

A helicopter is moving to the right at a constant horizontal velocity. It experiences three forces →Fgravitational,→Fdrag and force on it caused by rotor i.e. →Frotor. Which of the following diagrams can be correct free body diagram representing forces on the helicopter?

Answer»

A helicopter is moving to the right at a constant horizontal velocity. It experiences three forces ${\to F}_{g r a v i t a t i o n a l}, {\to F}_{d r a g}$ and force on it caused by rotor i.e. ${\to F}_{r o t o r}$ . Which of the following diagrams can be correct free body diagram representing forces on the helicopter?

Discussion

2696.	Three uniform rings made of the same material are arranged co-axially to form a system and the radii of the rings are r1=3 m,r2=2 m and r3=1 m. Find the y− coordinate of COM of the system.
Answer» Three uniform rings made of the same material are arranged co-axially to form a system and the radii of the rings are $r_{1} = 3 m, r_{2} = 2 m$ and $r_{3} = 1 m$ . Find the $y -$ coordinate of $COM$ of the system.

Discussion

2697.	41.An aeroplane is flying horizontally at an altitude of 2 km with 324 km per hour. How far from the target (horizontally) a bomb should be released so that it would hit the target?
Answer» 41.An aeroplane is flying horizontally at an altitude of 2 km with 324 km per hour. How far from the target (horizontally) a bomb should be released so that it would hit the target?

Discussion

2698.	Consider the Pressure vs Time graphs for two longitudinal waves A and B. What can you conclude about the amplitude and frequency of both the waves.(Assume that the graphs are drawn to the same scale.)
Answer» Consider the Pressure vs Time graphs for two longitudinal waves A and B. What can you conclude about the amplitude and frequency of both the waves. (Assume that the graphs are drawn to the same scale.)

Discussion

2699.	A simple pendulum of period T has a metal bob which is negatively charged. If it is allowed to oscillate above a large positively charged metallic plate, its period of oscillation will be:
Answer» A simple pendulum of period T has a metal bob which is negatively charged. If it is allowed to oscillate above a large positively charged metallic plate, its period of oscillation will be:

Discussion

2700.	If the constant electric field in the figure has a magnitude E0, calculate the total electric flux through the paraboloidal surface.
Answer» If the constant electric field in the figure has a magnitude $E_{0}$ , calculate the total electric flux through the paraboloidal surface.

Discussion

Explore topic-wise InterviewSolutions in .

An uninflates balloon has mass m.When it is inflated by blowing air of mass M into it.Its net weight will be

the angle between the vectors (icap+jcap) and (jcap+kcap) is?

Y = 4X2 how to find acceleration of the particle

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

If u=exsinx and v=excosx, then which of the following is/are true?

nt25 tuning forks are arranged in series in the order of decreasing frequency. Any two successive forks produce 3 beats/sec. If the frequency of the first tuning fork is the octave of the last fork,then the frequency of the 21st fork isn nta)72 Hzn ntb)288 Hzn ntc)84 Hzn ntd)87 Hzn

A closed tube filled with water is rotating as shown in figure. The pressure difference PA−PC is

A physical quantity X is related to four measurable quantities a, b, c and d as follows X=a2b3c5/2d−2 The percentage error in the measurement of a, b, c and d are 1%,2%,2% and 4% respectively. What is the percentage error in quantity X?

A charged conducting sphere of radius 1.3m has uniform surface charge density 50.0μ Cm^{-2}. The charge on the sphere is (1) 1.06×10^{-3 } C (2) 2.12×10^{-4} C (3) 0.50×10^{-3} C (4) 3.0×10^{-3} C

When √3 A current is passes through a tangent galvanometer, there is a deflection of 30∘ in it. The deflection obtained when 3 A current passing through it-

3.A disc of mass M kg and radius R metre is rotating at an angular speed of w rad/s when the motor is switched off. Neglecting the friction at the axle, the force that must be applied tangentially to the wheel to bring it to rest in time t is

A block of mass m kg is attached to a massless spring of spring constant k N/m. This system is accelerated upwards with an acceleration a m/s2. Then the elongation in spring will be (in metres):

locate the centre of mass of one quarter of risk of radius R.

Two blocks each of mass M are connected to the ends of a light frame as shown in below figure. The frame is rotated about the vertical line of symmetry. The rod breaks if the tension in it exceeds T0. Find the maximum frequency with which the frame may be rotated without breaking the rod.

why ZnO is yellow when hot and white whn cold?

If x and R stands for distance, then which of the following is dimensionally same as ∫Rdxx2?

What is chromatic aberration?

Find the gravitational potential energy of a system of four particles, each having mass m, placed at the vertices of a square of side l at the centre of the square.

A point charge of 2.0 μC is at the centre of a cubic Gaussian surface 9.0 cm on edge. What is the net electric flux through the surface?

A particle moves along a circle of radius (20π m) with constant tangential acceleration. If the velocity of the particle is 80 m/s at the end of the second revolution after motion has begun, the tangential acceleration is

emf of the cell cu/cu2+(1M)//ag+(0.1)/ag is x volt if concentration of anode and cathode are interchangedthen emf of cell becomes y so is x

A thin rod of mass m and lengthfrom one of its ends. It is set into oscillation abouta horizontal axis. Its angular speed is o whilepassing through its mean position. How high will itscentre of mass rise from its lowest position?suspended

A body of mass 100 g has a kinetic energy of 5 J. Find its linear momentum.

why do gases heat up when they expand above their inversion temperature?

What is enthalpy of a reaction?.

The variation of potential V with distance r from a fixed point is shown in the figure. The magnitude of electric field at r=2 cm is

A parallel plate capacitor is made by stacking n equally spaced plates connected alternatively. If the capacitance between any two adjacent plates is C, then the resultant capacitance is

1 mole of an ideal gas at initial temperature of T K does 6R joules of work adiabatically. If the ratio of specific heats of this gas at constant pressure and at constant volume is 53, then final temperature of the gas will be

A circular cylinder of mass m and radius r is connected by a spring of stiffness k on an inclined plane as shown in the figure below. If it is free to roll on the rough surface which is horizontal without slipping, then its natural frequency is

15.Two rods of equal lengths (l) and equal mass M are kept along x and y axis respectively such that their centre of mass lie at origin. The moment of inertia about a line y=x is

A force shown in the F−x graph is applied to a 5 kg cart, which then climbs up a ramp as shown. The maximum height Ymax the cart can reach (in m) is

If the shortest wavelengths of the continuous spectrum coming out of a Coolidge tube is 0.1 ∘A, then the de Broglie wavelength of the electron reaching the target metal in the Coolidge tube is approximately (hc=12400 eV−∘A,h=6.63×10−34 in MKS system andmass of electron=9.1×10−31 kg)

parallel plate capacitor of area A and separation between plate d, charged with current I. What is the displacement current through a plane of surface A/4 parallel to the plate and symmetrically drawn between the plate?

is particle is moving with a velocity V=3i+4j at an instant of time if a force F= 4i+6j+5K acts on the particle at that instant then the radius of curvature of the particle is (mass is 2kg)

The concept of limiting reagen

ntA planet of mass m moves around the sun of mass M in an elliptical orbit . The maximum and minimum distances of the planet from the sun are r1 and r2 respectively . The time period of the planet is proportional to ?n

a ball has been thrown vertically upward with initial velocity 20 m/s calculate distance and displacement at t is 3s

If a person has 3 of 10 rupees notes, 4 of 50 rupees notes and 2 of 100 rupees notes. How many ways can he give none or some notes to his friend Ram?

In a U tube experiment, a column AB of water is balanced by a column CD of paraffin. The relative density of paraffin is

Which of the following correctly represent schematically, the wave pattern produced by superposition of two waves of frequencies 9 Hz and 11 Hz is

16. Why we take change in internal energy in isothermal process as zero?

A helicopter is moving to the right at a constant horizontal velocity. It experiences three forces →Fgravitational,→Fdrag and force on it caused by rotor i.e. →Frotor. Which of the following diagrams can be correct free body diagram representing forces on the helicopter?

Three uniform rings made of the same material are arranged co-axially to form a system and the radii of the rings are r1=3 m,r2=2 m and r3=1 m. Find the y− coordinate of COM of the system.

41.An aeroplane is flying horizontally at an altitude of 2 km with 324 km per hour. How far from the target (horizontally) a bomb should be released so that it would hit the target?

Consider the Pressure vs Time graphs for two longitudinal waves A and B. What can you conclude about the amplitude and frequency of both the waves.(Assume that the graphs are drawn to the same scale.)

A simple pendulum of period T has a metal bob which is negatively charged. If it is allowed to oscillate above a large positively charged metallic plate, its period of oscillation will be:

If the constant electric field in the figure has a magnitude E0, calculate the total electric flux through the paraboloidal surface.