50278 + Interview Questions in Physics

1.	In Bainbridge mass spectrograph a potential difference of 1000 V is applied between two plates distant 1 cm apart and magnetic field in B = 1T. The velocity of undeflected positive ions in m/s from the velocity selector is
Answer» In Bainbridge mass spectrograph a potential difference of 1000 V is applied between two plates distant 1 cm apart and magnetic field in B = 1T. The velocity of undeflected positive ions in m/s from the velocity selector is

Discussion

2.	A tunnel is dug along a chord of the earth at a perpendicular distance R2 From the earth's centre. The wall of the tunnel may be assumed to be frictionless. Find the force exerted by the wall on a particle of mass m when it is at a distance x from the centre of the tunnel.
Answer» A tunnel is dug along a chord of the earth at a perpendicular distance $\frac{R}{2}$ From the earth's centre. The wall of the tunnel may be assumed to be frictionless. Find the force exerted by the wall on a particle of mass m when it is at a distance x from the centre of the tunnel.

Discussion

3.	The voltage across an electric bulb is decreased by 2%. Assuming that the resistance of the filament remains same, the power consumed will
Answer» The voltage across an electric bulb is decreased by 2%. Assuming that the resistance of the filament remains same, the power consumed will

Discussion

4.	Light is incident normally on face AB of a prism as shown in figure. A liquid of refractive index μis placed on face AC of the prism. The prism is made of glass of refractive index 32The limits of μ for which total internal reflection takes place on face AC is
Answer» Light is incident normally on face AB of a prism as shown in figure. A liquid of refractive index $μ$ is placed on face AC of the prism. The prism is made of glass of refractive index $\frac{3}{2}$ The limits of $μ$ for which total internal reflection takes place on face AC is

Discussion

5.	Planet A has mass M and radius R, Planet B has half the mass and half the radius of planet A. If the escape velocities from the planets A and B are vA and vB , respectively, then vAvB=n4, The value of n is:
Answer» Planet A has mass $M$ and radius $R$ , Planet B has half the mass and half the radius of planet A. If the escape velocities from the planets A and B are $v_{A}$ and $v_{B}$ , respectively, then $\frac{v_{A}}{v_{B}} = \frac{n}{4}$ , The value of n is:

Discussion

6.	An electron in accelerated through a potential difference of 45.5 V. The velocity acquired by it is (in ms−1)
Answer» An electron in accelerated through a potential difference of 45.5 V. The velocity acquired by it is $(i n m s^{- 1})$

Discussion

7.	The potential difference between B and C is 9 volts. Then R is ___
Answer» The potential difference between B and C is 9 volts. Then R is ___

Discussion

8.	In the circuit shown, the ideal voltmeter reading is 40 V. Find the value of unknown resistor R
Answer» In the circuit shown, the ideal voltmeter reading is $40 V$ . Find the value of unknown resistor $R$

Discussion

9.	The total electric flux, leaving spherical surface of radius 1 cm and surrounding an electric dipole is
Answer» The total electric flux, leaving spherical surface of radius 1 cm and surrounding an electric dipole is

Discussion

10.	Change Q on a capacitor varies with voltage V as shown in the figure, where Q is taken along the X-axis and V along the Y-axis. The area of triangle OAB represents
Answer» Change Q on a capacitor varies with voltage V as shown in the figure, where Q is taken along the X-axis and V along the Y-axis. The area of triangle OAB represents

10.

Change Q on a capacitor varies with voltage V as shown in the figure, where Q is taken along the X-axis and V along the Y-axis. The area of triangle OAB represents

Answer»

Change Q on a capacitor varies with voltage V as shown in the figure, where Q is taken along the X-axis and V along the Y-axis. The area of triangle OAB represents

Discussion

11.	A particle having mass m and charge q is released from the origin in a region in which electric field and magnetic fields are given by B=−B0^k and E=E^k. Find the speed of the particle as a function of its z coordinate.
Answer» A particle having mass m and charge q is released from the origin in a region in which electric field and magnetic fields are given by $B = - B_{0}^k$ and $E = E^k .$ Find the speed of the particle as a function of its z coordinate.

Discussion

12.	A hemisphere ball of radius R is set rotating about its axis of symmetry which is kept vertical. A small block kept in the bowl rotates with the bowl without slipping on its surface. If the surface of the bowl is smooth and the angle made by the radius through the block with the vertical is θ, find the angular speed at which the bowl is rotating.
Answer» A hemisphere ball of radius $R$ is set rotating about its axis of symmetry which is kept vertical. A small block kept in the bowl rotates with the bowl without slipping on its surface. If the surface of the bowl is smooth and the angle made by the radius through the block with the vertical is $θ$ , find the angular speed at which the bowl is rotating.

12.

A hemisphere ball of radius R is set rotating about its axis of symmetry which is kept vertical. A small block kept in the bowl rotates with the bowl without slipping on its surface. If the surface of the bowl is smooth and the angle made by the radius through the block with the vertical is θ, find the angular speed at which the bowl is rotating.

Answer»

A hemisphere ball of radius $R$ is set rotating about its axis of symmetry which is kept vertical. A small block kept in the bowl rotates with the bowl without slipping on its surface. If the surface of the bowl is smooth and the angle made by the radius through the block with the vertical is $θ$ , find the angular speed at which the bowl is rotating.

Discussion

13.	In the following circuit,the volt meter‘V’ shows 5 volts and ammeter ‘A’ shows 1 ampere then,the power consumed by the resistor Ris( in mW) ( Voltmeter and Ammete rare Ideal)
Answer» In the following circuit,the volt meter‘V’ shows 5 volts and ammeter ‘A’ shows 1 ampere then,the power consumed by the resistor Ris( in mW) ( Voltmeter and Ammete rare Ideal)

13.

In the following circuit,the volt meter‘V’ shows 5 volts and ammeter ‘A’ shows 1 ampere then,the power consumed by the resistor Ris( in mW) ( Voltmeter and Ammete rare Ideal)

Answer»

In the following circuit,the volt meter‘V’ shows 5 volts and ammeter ‘A’ shows 1 ampere then,the power consumed by the resistor Ris( in mW) ( Voltmeter and Ammete rare Ideal)

Discussion

14.	A block Q of mass m is placed on a frictionless horizontal surface. Another block P of same mass is kept on Q and connected to the wall with the help of a spring of spring constant k as shown in the figure. μs is the coefficient of friction between P and Q. The blocks move together performing SHM of amplitude A. The maximum value of the friction force between P and Q is
Answer» A block Q of mass m is placed on a frictionless horizontal surface. Another block P of same mass is kept on Q and connected to the wall with the help of a spring of spring constant k as shown in the figure. $μ_{s}$ is the coefficient of friction between P and Q. The blocks move together performing SHM of amplitude A. The maximum value of the friction force between P and Q is

Discussion

15.	Three particles, each of mass m, are situated at the vertices of an equilateral triangle of side 'a'. The only forces acting on the particles are their mutual gravitational forces. It is desired that each particle moves in a circle while maintaining their original separation 'a'. The initial velocity that should be given to each particle and time period of circular motion are respectively
Answer» Three particles, each of mass m, are situated at the vertices of an equilateral triangle of side 'a'. The only forces acting on the particles are their mutual gravitational forces. It is desired that each particle moves in a circle while maintaining their original separation 'a'. The initial velocity that should be given to each particle and time period of circular motion are respectively

Discussion

16.	A compressive force is applied to a uniform rod of rectangular cross-section so that its length decreases by 1%. If the Poisson's ratio for the material of the rod be 0.2, then volume approximately decreases by (in percentage).
Answer» A compressive force is applied to a uniform rod of rectangular cross-section so that its length decreases by 1%. If the Poisson's ratio for the material of the rod be $0.2$ , then volume approximately decreases by (in percentage).

Discussion

17.	A uniform disc of mass m and radius R=8023π2 is pivoted smoothly at point P. If another uniform ring of mass m and radius R is welded at the lowest point of the disc, the time period (in seconds) of the SHM of the system is
Answer» A uniform disc of mass $m$ and radius $R = \frac{80}{23 π^{2}}$ is pivoted smoothly at point $P$ . If another uniform ring of mass $m$ and radius $R$ is welded at the lowest point of the disc, the time period (in seconds) of the SHM of the system is

Discussion

18.	Two ideal springs of different lengths have been suspended from points A and B such that their free ends C and D are at the same horizontal level. A massless rod PQ is attached to the ends of the springs. A block of mass m is attached to the rod at point R. The rod remains horizontal in equilibrium. Now, the block is pulled down and released. It performs vertical oscillations with time period T=2π√m3k where k is the force constant of the longer spring. Find the ratio of lengths RC and RD.
Answer» Two ideal springs of different lengths have been suspended from points $A$ and $B$ such that their free ends $C$ and $D$ are at the same horizontal level. A massless rod $P Q$ is attached to the ends of the springs. A block of mass $m$ is attached to the rod at point $R$ . The rod remains horizontal in equilibrium. Now, the block is pulled down and released. It performs vertical oscillations with time period $T = 2 π \sqrt{\frac{m}{3 k}}$ where $k$ is the force constant of the longer spring. Find the ratio of lengths $R C$ and $R D$ .

Discussion

19.	You are riding in a car. The driver suddenly applies the brakes and you are pushed forward. Who pushed you forward?
Answer» You are riding in a car. The driver suddenly applies the brakes and you are pushed forward. Who pushed you forward?

Discussion

20.	The packing efficiency of the two-dimensional square unit cell shown below is:
Answer» The packing efficiency of the two-dimensional square unit cell shown below is:

20.

The packing efficiency of the two-dimensional square unit cell shown below is:

Answer»

The packing efficiency of the two-dimensional square unit cell shown below is:

Discussion

21.	Vectors →C and →D have magnitudes of 3 and 4 units respectively. What is the angle between the directions of →C and →D if the magnitude of vector product →C×→D is x and y respectively? (x) 0 (y) 12 units (i) 0 (ii)π2 (iii)π3 (iv) π4
Answer» Vectors $\to C$ and $\to D$ have magnitudes of 3 and 4 units respectively. What is the angle between the directions of $\to C$ and $\to D$ if the magnitude of vector product $\to C \times \to D$ is x and y respectively? (x) 0 (y) 12 units (i) 0 (ii) $\frac{π}{2}$ (iii) $\frac{π}{3}$ (iv) $\frac{π}{4}$

21.

Vectors →C and →D have magnitudes of 3 and 4 units respectively. What is the angle between the directions of →C and →D if the magnitude of vector product →C×→D is x and y respectively? (x) 0 (y) 12 units (i) 0 (ii)π2 (iii)π3 (iv) π4

Answer»

Vectors $\to C$ and $\to D$ have magnitudes of 3 and 4 units respectively. What is the angle between the directions of $\to C$ and $\to D$ if the magnitude of vector product $\to C \times \to D$ is x and y respectively?

(x) 0 (y) 12 units

(i) 0 (ii) $\frac{π}{2}$ (iii) $\frac{π}{3}$ (iv) $\frac{π}{4}$

Discussion

22.	A tuning fork produces 4 beats per second with another tuning fork of frequency 256 Hz. The first one is now loaded with a little wax and the beat frequency is found to increase to 6 per second. What was the original frequency of the tuning fork?
Answer» A tuning fork produces 4 beats per second with another tuning fork of frequency 256 Hz. The first one is now loaded with a little wax and the beat frequency is found to increase to 6 per second. What was the original frequency of the tuning fork?

Discussion

23.	A monochromatic beam of electrons accelerated by a potential difference V falls normally on the plane containing two narrow slits separated by a distance d. The interference pattern is observed on a screen parallel to the plane of the slits and at a distance of D from the slits. Fringe width is found to be w1. When electron beam is accelerated by the potential difference 4V, the fringe width becomes w2. Find the ratio w1w2. (Given d
Answer» A monochromatic beam of electrons accelerated by a potential difference $V$ falls normally on the plane containing two narrow slits separated by a distance $d$ . The interference pattern is observed on a screen parallel to the plane of the slits and at a distance of $D$ from the slits. Fringe width is found to be $w_{1}$ . When electron beam is accelerated by the potential difference $4 V,$ the fringe width becomes $w_{2}$ . Find the ratio $\frac{w_{1}}{w_{2}}$ . (Given d << D)

Discussion

24.	What is electric potential difference?
Answer» What is electric potential difference?

Discussion

25.	A river flows 3 km h−1 and a man is capable of swimming 2 km h−1. He wishes to cross it such that displacement parallel to river is minimum. In which direction will he swim?
Answer» A river flows $3 {km h}^{- 1}$ and a man is capable of swimming $2 {km h}^{- 1}$ . He wishes to cross it such that displacement parallel to river is minimum. In which direction will he swim?

Discussion

26.	Is the drift speed for a charge is (EeT)2m or EeTm?
Answer» Is the drift speed for a charge is $\frac{(E e T)}{2 m} o r \frac{E e T}{m}$ ?

Discussion

27.	A block placed on a horizontal surface is being pushed by a force F making an angle θ with the vertical. The coefficient of friction between block and surface is μ. The force required to slide the block with uniform velocity on the floor is
Answer» A block placed on a horizontal surface is being pushed by a force F making an angle $θ$ with the vertical. The coefficient of friction between block and surface is $μ$ . The force required to slide the block with uniform velocity on the floor is

Discussion

28.	The relative luminosity of wavelength 600 nm is0.6 Find the radiant flux of 600 nm needed to produce the same brightness sensation as produced by 120 W of radiant flux at 555nm.
Answer» The relative luminosity of wavelength 600 nm is0.6 Find the radiant flux of 600 nm needed to produce the same brightness sensation as produced by 120 W of radiant flux at 555nm.

Discussion

29.	The graph given shows the velocity v versus time t for a body. Which of the following graphs shown represents the corresponding acceleration versus time graph ?
Answer» The graph given shows the velocity $v$ versus time $t$ for a body. Which of the following graphs shown represents the corresponding acceleration versus time graph ?

Discussion

30.	What is the angle between the following pair vectors? →A=^i+^j+^k and →B=−2^i−2^j−2^k
Answer» What is the angle between the following pair vectors? $\to A =^i +^j +^k a n d \to B = - 2^i - 2^j - 2^k$

Discussion

31.	If a star can convert four "He" nuclei completely into oxygen nuclei , then calculate energy released per oxygen nuclei in MeV . given that mass of the "He" nucleus is 4.0026 amu and mass of oxygen nucleus is 15.9994 amu .(please leave 2 cm margin from the right side while taking the picture).
Answer» If a star can convert four "He" nuclei completely into oxygen nuclei , then calculate energy released per oxygen nuclei in MeV . given that mass of the "He" nucleus is 4.0026 amu and mass of oxygen nucleus is 15.9994 amu .(please leave 2 cm margin from the right side while taking the picture).

Discussion

32.	A bird is flying due east with a velocity of 4 m/s. The wind starts to blow with a velocity of 3 m/s due north. What is the magnitude of relative velocity of bird w.r.t. wind? Find out the angle it makes with the x-axis?
Answer» A bird is flying due east with a velocity of 4 m/s. The wind starts to blow with a velocity of 3 m/s due north. What is the magnitude of relative velocity of bird w.r.t. wind? Find out the angle it makes with the x-axis?

Discussion

33.	The intensity of radiation from a human body is maximum around a certain wavelength. A photon of this wavelength can just excite an electron from the valence to the conduction band of a semiconductor used in a night vision device. Assume that the black body radiation law holds for the human body. The band gap of such a semiconductor is close to (A) 0.1 eV (B) 0.5 eV (C) 1.0 eV (D) 2.0 eV
Answer» The intensity of radiation from a human body is maximum around a certain wavelength. A photon of this wavelength can just excite an electron from the valence to the conduction band of a semiconductor used in a night vision device. Assume that the black body radiation law holds for the human body. The band gap of such a semiconductor is close to (A) 0.1 eV (B) 0.5 eV (C) 1.0 eV (D) 2.0 eV

Discussion

34.	Newton's second law of motion is based on ___ of momentum.
Answer» Newton's second law of motion is based on ___ of momentum.

Discussion

35.	A voltage of peak value 283 V with varying frequency is applied to a series L−C−R combination in which R=3 Ω,L=25 mH and C=400 μF. Then, the frequency (in Hz) of the source at which maximum power is dissipated in the above circuit is
Answer» A voltage of peak value $283 V$ with varying frequency is applied to a series $L - C - R$ combination in which $R = 3 Ω, L = 25 mH$ and $C = 400 μ F$ . Then, the frequency (in $Hz$ ) of the source at which maximum power is dissipated in the above circuit is

Discussion

36.	Find the value of force F, if the tension in the string connecting the 2 kg block and 3 kg block is T=20 N. Consider all surfaces to be smooth.
Answer» Find the value of force $F$ , if the tension in the string connecting the $2 k g$ block and $3 k g$ block is $T = 20 N$ . Consider all surfaces to be smooth.

Discussion

37.	A solid sphere of mass 2 kg is resting inside a cube as shown in the figure. The cube is moving with a velocity v=(5t^i+2t^j) m/s. Here t is the time in second. All surface are smooth. The sphere is at rest with respect to the cube. What is the total force exerted by the sphere on the cube. (Take g=10 m/s2)
Answer» A solid sphere of mass 2 kg is resting inside a cube as shown in the figure. The cube is moving with a velocity $v = (5 t^i + 2 t^j) m/s$ . Here $t$ is the time in second. All surface are smooth. The sphere is at rest with respect to the cube. What is the total force exerted by the sphere on the cube. (Take $g = 10 m / s^{2}$ )

Discussion

38.	At what temperature the velocity of O2 molecules have the same velocity as SO2 at 47∘ C?
Answer» At what temperature the velocity of $O_{2}$ molecules have the same velocity as $S O_{2}$ at $47^{\circ}$ C?

Discussion

39.	What is the maximum distance between real object and real image in the case of concave mirror? A)2f . B)f. C) 0. D)4f Explain with reason
Answer» What is the maximum distance between real object and real image in the case of concave mirror? A)2f . B)f. C) 0. D)4f Explain with reason

39.

What is the maximum distance between real object and real image in the case of concave mirror? A)2f . B)f. C) 0. D)4f Explain with reason

Answer»

What is the maximum distance between real object and real image in the case of concave mirror?

A)2f . B)f. C) 0. D)4f

Explain with reason

Discussion

40.	A horizontal disc rotating freely about a vertical axis makes 200 rpm. A piece of wax of mass 20 g falls verticaly on the disc and adheres to it at a distance of 8 cm from the axis. If the number of revolutions per minute is thereby reduced to 120 rpm, then calculate the moment of inertia of disc.
Answer» A horizontal disc rotating freely about a vertical axis makes $200 rpm$ . A piece of wax of mass $20 g$ falls verticaly on the disc and adheres to it at a distance of $8 cm$ from the axis. If the number of revolutions per minute is thereby reduced to $120 rpm$ , then calculate the moment of inertia of disc.

Discussion

41.	Deduced from the following E∘ values of half cells, what combination of two half cells would result in a cell with the largest potential? (i) A3−→A2−+e;E∘=1.5V (ii) B2++e→B+;E∘=2.1V (iii) C2++e→C+;E∘=+0.5V (iv) D→D2++2e;E∘=−1.5V
Answer» Deduced from the following $E^{\circ}$ values of half cells, what combination of two half cells would result in a cell with the largest potential? (i) $A^{3 -} \to A^{2 -} + e; E^{\circ} = 1.5 V$ (ii) $B^{2 +} + e \to B^{+}; E^{\circ} = 2.1 V$ (iii) $C^{2 +} + e \to C^{+}; E^{\circ} = + 0.5 V$ (iv) $D \to D^{2 +} + 2 e; E^{\circ} = - 1.5 V$

Discussion

42.	A trinary star system has a time period, T=3 years, while the distance between its components is 2 astronomical unit. If mass of the sun is represented by Ms, then the total mass of this multiple star system will be Note : (1) System of three star, orbiting around centre of mass of system, is called trinary star system. For simplicity assume all three components to be identical. (2) 1 astronomical unit = distance between earth and sun (3) 1 year = time period of earth to complete one full revolution around sun
Answer» A trinary star system has a time period, $T = 3$ years, while the distance between its components is $2$ astronomical unit. If mass of the sun is represented by $M_{s}$ , then the total mass of this multiple star system will be Note : (1) System of three star, orbiting around centre of mass of system, is called trinary star system. For simplicity assume all three components to be identical. (2) 1 astronomical unit = distance between earth and sun (3) 1 year = time period of earth to complete one full revolution around sun

Discussion

43.	How electric field produce acceleration in cycloton by which property of electric field is partial accerate
Answer» How electric field produce acceleration in cycloton by which property of electric field is partial accerate

Discussion

44.	The basis of long form of periodic table is:
Answer» The basis of long form of periodic table is:

Discussion

45.	Mass is distributed uniformly over a thin triangular plate and positions of two vertical are given by (1,3) and (2,−4). What is the position of third vertex, if centre of mass of the plate lies at the origin?
Answer» Mass is distributed uniformly over a thin triangular plate and positions of two vertical are given by $(1, 3)$ and $(2, - 4)$ . What is the position of third vertex, if centre of mass of the plate lies at the origin?

Discussion

46.	Twelve wires, each having equal resistance of 2 Ω, are joined to form a cube. What is the equivalent resistance between the ends of a face diagonal?
Answer» Twelve wires, each having equal resistance of 2 $Ω$ , are joined to form a cube. What is the equivalent resistance between the ends of a face diagonal?

Discussion

47.	Common Emitter Amplifier The so called classic common emitter configuration uses a potential divider network to bias the transistors Base. Power supply Vcc and the biasing resistors set the transistor operating point to conduct in the forward active mode. With no signal current flow into the Base, no Collector current flows, (transistor in cut-off) and the voltage on the Collector is the same as the supply voltage, Vcc. A signal current into the Base causes a current to flow in the Collector resistor, Rc generating a voltage drop across it which causes the Collector voltage to drop. Then the direction of change of the Collector voltage is opposite to the direction of change on the Base, in other words, the polarity is reversed. Thus the common emitter configuration produces a large voltage amplification and a well defined DC voltage level by taking the output voltage from across the collector as shown with resistor RLrepresenting the load across the output. Please explain me the above paragraphs. And also conclude that how is the input impedance of common emitter configuration high and how does this affect the high current gain and power gain of this type of configuration.
Answer» Common Emitter Amplifier The so called classic common emitter configuration uses a potential divider network to bias the transistors Base. Power supply Vcc and the biasing resistors set the transistor operating point to conduct in the forward active mode. With no signal current flow into the Base, no Collector current flows, (transistor in cut-off) and the voltage on the Collector is the same as the supply voltage, Vcc. A signal current into the Base causes a current to flow in the Collector resistor, Rc generating a voltage drop across it which causes the Collector voltage to drop. Then the direction of change of the Collector voltage is opposite to the direction of change on the Base, in other words, the polarity is reversed. Thus the common emitter configuration produces a large voltage amplification and a well defined DC voltage level by taking the output voltage from across the collector as shown with resistor R_Lrepresenting the load across the output. Please explain me the above paragraphs. And also conclude that how is the input impedance of common emitter configuration high and how does this affect the high current gain and power gain of this type of configuration.

47.

Common Emitter Amplifier The so called classic common emitter configuration uses a potential divider network to bias the transistors Base. Power supply Vcc and the biasing resistors set the transistor operating point to conduct in the forward active mode. With no signal current flow into the Base, no Collector current flows, (transistor in cut-off) and the voltage on the Collector is the same as the supply voltage, Vcc. A signal current into the Base causes a current to flow in the Collector resistor, Rc generating a voltage drop across it which causes the Collector voltage to drop. Then the direction of change of the Collector voltage is opposite to the direction of change on the Base, in other words, the polarity is reversed. Thus the common emitter configuration produces a large voltage amplification and a well defined DC voltage level by taking the output voltage from across the collector as shown with resistor RLrepresenting the load across the output. Please explain me the above paragraphs. And also conclude that how is the input impedance of common emitter configuration high and how does this affect the high current gain and power gain of this type of configuration.

Answer» Common Emitter Amplifier

The so called classic common emitter configuration uses a potential divider network to bias the transistors Base. Power supply Vcc and the biasing resistors set the transistor operating point to conduct in the forward active mode. With no signal current flow into the Base, no Collector current flows, (transistor in cut-off) and the voltage on the Collector is the same as the supply voltage, Vcc. A signal current into the Base causes a current to flow in the Collector resistor, Rc generating a voltage drop across it which causes the Collector voltage to drop.

Then the direction of change of the Collector voltage is opposite to the direction of change on the Base, in other words, the polarity is reversed. Thus the common emitter configuration produces a large voltage amplification and a well defined DC voltage level by taking the output voltage from across the collector as shown with resistor R_Lrepresenting the load across the output.

Please explain me the above paragraphs.
And also conclude that how is the input impedance of common emitter configuration high and how does this affect the high current gain and power gain of this type of configuration.

Discussion

48.	The frequency changes by 10% as the source approaches a stationary observer with constant speed Vs. What should be the percentage change in frequency as the source recedes from the observer with the same speed? Given that Vs ≪ v(v is the speed of sound in air).
Answer» The frequency changes by 10% as the source approaches a stationary observer with constant speed Vs. What should be the percentage change in frequency as the source recedes from the observer with the same speed? Given that Vs ≪ v(v is the speed of sound in air).

Discussion

49.	How much should be the percentage decrease in pressure (approximately) to increase the volume of a given mass of a gas by 10% at a constant temperature?___
Answer» How much should be the percentage decrease in pressure (approximately) to increase the volume of a given mass of a gas by $10 %$ at a constant temperature?___

Discussion

50.	A uniform chain is held on a frictionless table with one third of its length hanging over the edge.if the chain has a length L and mass M, how much work is required to pull the Hanging part back on the table.
Answer» A uniform chain is held on a frictionless table with one third of its length hanging over the edge.if the chain has a length L and mass M, how much work is required to pull the Hanging part back on the table.

Discussion

Explore topic-wise InterviewSolutions in Current Affairs.

In Bainbridge mass spectrograph a potential difference of 1000 V is applied between two plates distant 1 cm apart and magnetic field in B = 1T. The velocity of undeflected positive ions in m/s from the velocity selector is

A tunnel is dug along a chord of the earth at a perpendicular distance R2 From the earth's centre. The wall of the tunnel may be assumed to be frictionless. Find the force exerted by the wall on a particle of mass m when it is at a distance x from the centre of the tunnel.

The voltage across an electric bulb is decreased by 2%. Assuming that the resistance of the filament remains same, the power consumed will

Light is incident normally on face AB of a prism as shown in figure. A liquid of refractive index μis placed on face AC of the prism. The prism is made of glass of refractive index 32The limits of μ for which total internal reflection takes place on face AC is

Planet A has mass M and radius R, Planet B has half the mass and half the radius of planet A. If the escape velocities from the planets A and B are vA and vB , respectively, then vAvB=n4, The value of n is:

An electron in accelerated through a potential difference of 45.5 V. The velocity acquired by it is (in ms−1)

The potential difference between B and C is 9 volts. Then R is ___

In the circuit shown, the ideal voltmeter reading is 40 V. Find the value of unknown resistor R

The total electric flux, leaving spherical surface of radius 1 cm and surrounding an electric dipole is

Change Q on a capacitor varies with voltage V as shown in the figure, where Q is taken along the X-axis and V along the Y-axis. The area of triangle OAB represents

A particle having mass m and charge q is released from the origin in a region in which electric field and magnetic fields are given by B=−B0^k and E=E^k. Find the speed of the particle as a function of its z coordinate.

In the following circuit,the volt meter‘V’ shows 5 volts and ammeter ‘A’ shows 1 ampere then,the power consumed by the resistor Ris( in mW) ( Voltmeter and Ammete rare Ideal)

A compressive force is applied to a uniform rod of rectangular cross-section so that its length decreases by 1%. If the Poisson's ratio for the material of the rod be 0.2, then volume approximately decreases by (in percentage).

A uniform disc of mass m and radius R=8023π2 is pivoted smoothly at point P. If another uniform ring of mass m and radius R is welded at the lowest point of the disc, the time period (in seconds) of the SHM of the system is

You are riding in a car. The driver suddenly applies the brakes and you are pushed forward. Who pushed you forward?

The packing efficiency of the two-dimensional square unit cell shown below is:

Vectors →C and →D have magnitudes of 3 and 4 units respectively. What is the angle between the directions of →C and →D if the magnitude of vector product →C×→D is x and y respectively? (x) 0 (y) 12 units (i) 0 (ii)π2 (iii)π3 (iv) π4

A tuning fork produces 4 beats per second with another tuning fork of frequency 256 Hz. The first one is now loaded with a little wax and the beat frequency is found to increase to 6 per second. What was the original frequency of the tuning fork?

What is electric potential difference?

A river flows 3 km h−1 and a man is capable of swimming 2 km h−1. He wishes to cross it such that displacement parallel to river is minimum. In which direction will he swim?

Is the drift speed for a charge is (EeT)2m or EeTm?

A block placed on a horizontal surface is being pushed by a force F making an angle θ with the vertical. The coefficient of friction between block and surface is μ. The force required to slide the block with uniform velocity on the floor is

The relative luminosity of wavelength 600 nm is0.6 Find the radiant flux of 600 nm needed to produce the same brightness sensation as produced by 120 W of radiant flux at 555nm.

The graph given shows the velocity v versus time t for a body. Which of the following graphs shown represents the corresponding acceleration versus time graph ?

What is the angle between the following pair vectors? →A=^i+^j+^k and →B=−2^i−2^j−2^k

If a star can convert four "He" nuclei completely into oxygen nuclei , then calculate energy released per oxygen nuclei in MeV . given that mass of the "He" nucleus is 4.0026 amu and mass of oxygen nucleus is 15.9994 amu .(please leave 2 cm margin from the right side while taking the picture).

A bird is flying due east with a velocity of 4 m/s. The wind starts to blow with a velocity of 3 m/s due north. What is the magnitude of relative velocity of bird w.r.t. wind? Find out the angle it makes with the x-axis?

Newton's second law of motion is based on ___ of momentum.

A voltage of peak value 283 V with varying frequency is applied to a series L−C−R combination in which R=3 Ω,L=25 mH and C=400 μF. Then, the frequency (in Hz) of the source at which maximum power is dissipated in the above circuit is

Find the value of force F, if the tension in the string connecting the 2 kg block and 3 kg block is T=20 N. Consider all surfaces to be smooth.

At what temperature the velocity of O2 molecules have the same velocity as SO2 at 47∘ C?

What is the maximum distance between real object and real image in the case of concave mirror? A)2f . B)f. C) 0. D)4f Explain with reason

A horizontal disc rotating freely about a vertical axis makes 200 rpm. A piece of wax of mass 20 g falls verticaly on the disc and adheres to it at a distance of 8 cm from the axis. If the number of revolutions per minute is thereby reduced to 120 rpm, then calculate the moment of inertia of disc.

Deduced from the following E∘ values of half cells, what combination of two half cells would result in a cell with the largest potential? (i) A3−→A2−+e;E∘=1.5V (ii) B2++e→B+;E∘=2.1V (iii) C2++e→C+;E∘=+0.5V (iv) D→D2++2e;E∘=−1.5V

How electric field produce acceleration in cycloton by which property of electric field is partial accerate

The basis of long form of periodic table is:

Mass is distributed uniformly over a thin triangular plate and positions of two vertical are given by (1,3) and (2,−4). What is the position of third vertex, if centre of mass of the plate lies at the origin?

Twelve wires, each having equal resistance of 2 Ω, are joined to form a cube. What is the equivalent resistance between the ends of a face diagonal?

The frequency changes by 10% as the source approaches a stationary observer with constant speed Vs. What should be the percentage change in frequency as the source recedes from the observer with the same speed? Given that Vs ≪ v(v is the speed of sound in air).

How much should be the percentage decrease in pressure (approximately) to increase the volume of a given mass of a gas by 10% at a constant temperature?___

A uniform chain is held on a frictionless table with one third of its length hanging over the edge.if the chain has a length L and mass M, how much work is required to pull the Hanging part back on the table.