16569 + Interview Questions in Physics Page 30 InterviewSolution

1451.	Question 35The image of a candle flame formed by a lens is obtained on a screen placed on the other side of the lens. If the image is three times the size of the flame and the distance between lens and image is 80 cm, at what distance should the candle be placed from the lens? What is the nature of the image at a distance of 80 cm and the lens?
Answer» Question 35 The image of a candle flame formed by a lens is obtained on a screen placed on the other side of the lens. If the image is three times the size of the flame and the distance between lens and image is 80 cm, at what distance should the candle be placed from the lens? What is the nature of the image at a distance of 80 cm and the lens?

Discussion

1452.	Name the physical quantity whose unit is “electron volt”. Express 5.6 electron volt in terms of its SI unit.
Answer» Name the physical quantity whose unit is “electron volt”. Express 5.6 electron volt in terms of its SI unit.

Discussion

1453.	A concave lens forms the image of a real object such that the distance between the object and image is 10 cm and the magnification produced is 1/4. The focal length of the lens will be :
Answer» A concave lens forms the image of a real object such that the distance between the object and image is $10 cm$ and the magnification produced is $1 / 4$ . The focal length of the lens will be :

Discussion

1454.	If the key in the arrangement is taken out (the circuit is made open) and magnetic field lines are drawn over the horizontal plane ABCD, the lines are:
Answer» If the key in the arrangement is taken out (the circuit is made open) and magnetic field lines are drawn over the horizontal plane ABCD, the lines are:

Discussion

1455.	Use Huygens’ principle to arrive at Snell’s law using a plane wavefront and acrossa plane surface.
Answer» Use Huygens’ principle to arrive at Snell’s law using a plane wavefront and across a plane surface.

Discussion

1456.	The wire in Figure below is being moved downwards throught are magnetic fields so as to produce induced current. What would be the effect of : (a) moving the wire at a higher speed ? (b) moving the wire upwards rather than downwards ? (c) using a stronger magnet ? (d) holding the wire still in the magnetic field ? (e) moving the wire parallel to the magnetic field lines ?
Answer» The wire in Figure below is being moved downwards throught are magnetic fields so as to produce induced current. What would be the effect of : (a) moving the wire at a higher speed ? (b) moving the wire upwards rather than downwards ? (c) using a stronger magnet ? (d) holding the wire still in the magnetic field ? (e) moving the wire parallel to the magnetic field lines ?

1456.

The wire in Figure below is being moved downwards throught are magnetic fields so as to produce induced current. What would be the effect of : (a) moving the wire at a higher speed ? (b) moving the wire upwards rather than downwards ? (c) using a stronger magnet ? (d) holding the wire still in the magnetic field ? (e) moving the wire parallel to the magnetic field lines ?

Answer»

The wire in Figure below is being moved downwards throught are magnetic fields so as to produce induced current.

What would be the effect of :

(a) moving the wire at a higher speed ?

(b) moving the wire upwards rather than downwards ?

(c) using a stronger magnet ?

(d) holding the wire still in the magnetic field ?

(e) moving the wire parallel to the magnetic field lines ?

Discussion

1457.	(a) A small object is placed 150 mm away from a diverging lens of focal length 100 mm. (i) Copy the figure below and draw rays to show how an image is formed by the lens. (ii) Calculate the distance of the image from the lens by using the lens formula. (b) The diverging lens in part (a) is replaced by a converging lens also of focal length 100 mm. The object remains in the same position and an image is formed by the converging lens. Compare two properties of this image with those of the image formed by the diverging lens in part (a).
Answer» (a) A small object is placed 150 mm away from a diverging lens of focal length 100 mm. (i) Copy the figure below and draw rays to show how an image is formed by the lens. (ii) Calculate the distance of the image from the lens by using the lens formula. (b) The diverging lens in part (a) is replaced by a converging lens also of focal length 100 mm. The object remains in the same position and an image is formed by the converging lens. Compare two properties of this image with those of the image formed by the diverging lens in part (a).

1457.

(a) A small object is placed 150 mm away from a diverging lens of focal length 100 mm. (i) Copy the figure below and draw rays to show how an image is formed by the lens. (ii) Calculate the distance of the image from the lens by using the lens formula. (b) The diverging lens in part (a) is replaced by a converging lens also of focal length 100 mm. The object remains in the same position and an image is formed by the converging lens. Compare two properties of this image with those of the image formed by the diverging lens in part (a).

Answer»

(a) A small object is placed 150 mm away from a diverging lens of focal length 100 mm. (i) Copy the figure below and draw rays to show how an image is formed by the lens. (ii) Calculate the distance of the image from the lens by using the lens formula. (b) The diverging lens in part (a) is replaced by a converging lens also of focal length 100 mm. The object remains in the same position and an image is formed by the converging lens. Compare two properties of this image with those of the image formed by the diverging lens in part (a).

Discussion

1458.	is the weak nuclear force inversely proportional to the macroscopic domain?
Answer» is the weak nuclear force inversely proportional to the macroscopic domain?

Discussion

1459.	ntA: Voltage across a resistor decreases in the direction of current and increases opposite to the direction of current.n ntR: Voltage drop or gain across a capacitor depends on the direction of current.n ntn ntExplain the correct reason as well as how reason is incorrect.n ntn
Answer» ntA: Voltage across a resistor decreases in the direction of current and increases opposite to the direction of current.n ntR: Voltage drop or gain across a capacitor depends on the direction of current.n ntn ntExplain the correct reason as well as how reason is incorrect.n ntn

Discussion

1460.	What is the difference between resistivity and resistance.conductivity and conductance
Answer» What is the difference between resistivity and resistance.conductivity and conductance

Discussion

1461.	a projectile is projected with a speed 10m/s at an angle θ with the horizontal.if the horizontal range is 10m,then θ is (g=10m/s^2
Answer» a projectile is projected with a speed 10m/s at an angle θ with the horizontal.if the horizontal range is 10m,then θ is (g=10m/s^2

Discussion

1462.	If there is always a small spacing between two bodies in contact with each other how is friction generated.?
Answer» If there is always a small spacing between two bodies in contact with each other how is friction generated.?

Discussion

1463.	24. The current reading of ammeter is i1 when k1 (only) is closed and i2 when k2 (only) is closed, then 1) i1i2 3) i1=i2 4) i1=\sqrt{}2i2
Answer» 24. The current reading of ammeter is i1 when k1 (only) is closed and i2 when k2 (only) is closed, then 1) i1i2 3) i1=i2 4) i1=\sqrt{}2i2

Discussion

1464.	An accident in a nuclear laboratory resulted in deposition of a certain amount of radioactive material of half-life 18 days inside the laboratory. Tests revealed that the radiation was 64 times more than the permissible level required for safe operation of the laboratory. What is the minimum number of days after which the laboratory can be considered safe for use?
Answer» An accident in a nuclear laboratory resulted in deposition of a certain amount of radioactive material of half-life $18$ days inside the laboratory. Tests revealed that the radiation was $64$ times more than the permissible level required for safe operation of the laboratory. What is the minimum number of days after which the laboratory can be considered safe for use?

Discussion

1465.	How did Benjamin Franklin invent the charges?
Answer» How did Benjamin Franklin invent the charges?

Discussion

1466.	If α and β are the eccentric angles of the extremities of a focal chord of an ellipse, then the eccentricity of the ellipse is
Answer» If α and β are the eccentric angles of the extremities of a focal chord of an ellipse, then the eccentricity of the ellipse is

Discussion

1467.	A postage stamp kept below a rectangular glass slab of refractive index 1.5 when viewed from vertically above it, appears to be raised by 7.0 mm. Calculate the thickness of the glass slab.
Answer» A postage stamp kept below a rectangular glass slab of refractive index 1.5 when viewed from vertically above it, appears to be raised by 7.0 mm. Calculate the thickness of the glass slab.

Discussion

1468.	97.Mechanism of beckmann rearrangement
Answer» 97.Mechanism of beckmann rearrangement

Discussion

1469.	A steady current is flowing in a cylindrical conductor.Is there any electric field within the conductor?
Answer» A steady current is flowing in a cylindrical conductor.Is there any electric field within the conductor?

Discussion

1470.	Calculate the energy radiated per minute from the filament of an incandescent lamp at 2000K if the surface area is 5×10^-5 m^2and its relative emittance is 0.85, sigma= 5.7×10^-8 MKS units
Answer» Calculate the energy radiated per minute from the filament of an incandescent lamp at 2000K if the surface area is 5×10^-5 m^2 and its relative emittance is 0.85, sigma= 5.7×10^-8 MKS units

Discussion

1471.	Question 8In the figure of the human eye, the cornea is represented by the letter.(a) A(b) B(c) C(d) D
Answer» Question 8 In the figure of the human eye, the cornea is represented by the letter. (a) A (b) B (c) C (d) D

1471.

Question 8In the figure of the human eye, the cornea is represented by the letter.(a) A(b) B(c) C(d) D

Answer»

Question 8

In the figure of the human eye, the cornea is represented by the letter.

(a) A

(b) B

(c) C

(d) D

Discussion

1472.	Arrange the rays in electromagnetic spectrum according to the increasing order of wavelength. (1) Infrared rays, (2) X rays, (3) Radiowaves, (4) Microwaves, (5) Gamma rays, (6) UV rays.
Answer» Arrange the rays in electromagnetic spectrum according to the increasing order of wavelength. (1) Infrared rays, (2) X rays, (3) Radiowaves, (4) Microwaves, (5) Gamma rays, (6) UV rays.

Discussion

1473.	The period of oscillation of a simple pendulum of length l suspended from the roof of a vehicle which moves without friction down an inclined plane of inclination α, is given by
Answer» The period of oscillation of a simple pendulum of length $l$ suspended from the roof of a vehicle which moves without friction down an inclined plane of inclination $α$ , is given by

Discussion

1474.	6. For a concave mirror, paraxial rays are focused at distance R/2 from pole and marginal rays are focused atdistance x from pole, then (R is radius of curvature)
Answer» 6. For a concave mirror, paraxial rays are focused at distance R/2 from pole and marginal rays are focused atdistance x from pole, then (R is radius of curvature)

Discussion

1475.	Describe and explain, how are normal I can see objects link at various distances clearly.
Answer» Describe and explain, how are normal I can see objects link at various distances clearly.

Discussion

1476.	A rectangular glass slab ABCD, of refractive index n1, is immersed in water of refractive index n2 (n1>n2). A ray of light in incident at the surface AB of the slab as shown. The maximum value of the angle of incidence amax, such that the ray comes out only from the other surface CD is given by
Answer» A rectangular glass slab ABCD, of refractive index n₁, is immersed in water of refractive index n₂ (n₁>n₂). A ray of light in incident at the surface AB of the slab as shown. The maximum value of the angle of incidence a_max, such that the ray comes out only from the other surface CD is given by

1476.

A rectangular glass slab ABCD, of refractive index n1, is immersed in water of refractive index n2 (n1>n2). A ray of light in incident at the surface AB of the slab as shown. The maximum value of the angle of incidence amax, such that the ray comes out only from the other surface CD is given by

Answer»

A rectangular glass slab ABCD, of refractive index n₁, is immersed in water of refractive index n₂ (n₁>n₂). A ray of light in incident at the surface AB of the slab as shown. The maximum value of the angle of incidence a_max, such that the ray comes out only from the other surface CD is given by

Discussion

1477.	Let mp be the mass of a proton, mn the mass of a neutron, M1 is the mass of a 2010Ne nucleus & M2 is the mass of a 4020Ca nucleus. Then
Answer» Let $m_{p}$ be the mass of a proton, $m_{n}$ the mass of a neutron, $M_{1}$ is the mass of a $_{10}^{20} Ne$ nucleus & $M_{2}$ is the mass of a $_{20}^{40} Ca$ nucleus. Then

Discussion

1478.	Skin cancer is caused by___rays.
Answer» Skin cancer is caused by___rays.

Discussion

1479.	For a particle (tied with massless string) to completemotion in a vertical circle of radius r, the minimumvelocity required at its lowest position is
Answer» For a particle (tied with massless string) to completemotion in a vertical circle of radius r, the minimumvelocity required at its lowest position is

Discussion

1480.	In wireless communication how em waves carry messages how the message is coded
Answer» In wireless communication how em waves carry messages how the message is coded

Discussion

1481.	For a person, the distance of eye lens from the retina is 2.00 cm and maximum focal length of the eye lens is 1.96 cm. Find the far point of the person.
Answer» For a person, the distance of eye lens from the retina is $2.00 cm$ and maximum focal length of the eye lens is $1.96 cm$ . Find the far point of the person.

Discussion

1482.	31.A block is kept on a horizontal table. The table is undergoing SHM of frequency 3Hz in a horizontal place. The coefficient of static friction between block and table surface is 0.72 . Find the Maximum amplitude of the table in such block doesn't slip on the surface
Answer» 31.A block is kept on a horizontal table. The table is undergoing SHM of frequency 3Hz in a horizontal place. The coefficient of static friction between block and table surface is 0.72 . Find the Maximum amplitude of the table in such block doesn't slip on the surface

Discussion

1483.	Calculate the current through a 60 W lamp rated for 250 V. If the line voltage falls to 200 V, how is the power consumed by the lamp affected?
Answer» Calculate the current through a 60 W lamp rated for 250 V. If the line voltage falls to 200 V, how is the power consumed by the lamp affected?

Discussion

1484.	A long staright wire carrying 5A current lies in the plane of the paper as shown in the given figure. Find the magnitude and direction of the magnetic field at point P. [Given μ0=4π×10−7Tm/A]
Answer» A long staright wire carrying 5A current lies in the plane of the paper as shown in the given figure. Find the magnitude and direction of the magnetic field at point P. $[Given μ_{0} = 4 π \times 10^{- 7} T m / A]$

Discussion

1485.	What does a rating of '916' on a gold ornament indicate?
Answer» What does a rating of '916' on a gold ornament indicate?

Discussion

1486.	Two identical cells whether joined together in series or in parallel give the same current, when connected to externalresistance of 2 . Their internal resistance r is
Answer» Two identical cells whether joined together in series or in parallel give the same current, when connected to external resistance of 2 . Their internal resistance r is

Discussion

1487.	a simple pendulum of infinite length has infinite kinetic energy at mean position (so its velocity should be greater than escape velocity) then why it returns back?what is the force acting at extreme position i.e. infinity?
Answer» a simple pendulum of infinite length has infinite kinetic energy at mean position (so its velocity should be greater than escape velocity) then why it returns back? what is the force acting at extreme position i.e. infinity?

Discussion

1488.	23.Why work done by external force is taken as positive and work done by Conservative electrostatic force is taken as negative
Answer» 23.Why work done by external force is taken as positive and work done by Conservative electrostatic force is taken as negative

Discussion

1489.	c) A bulb is connected to a battery of potential difference 4 V and internal resistance 2.50A steady current of 0.5 A flows through the circuit. Calculate the resistance of the bulb
Answer» c) A bulb is connected to a battery of potential difference 4 V and internal resistance 2.50A steady current of 0.5 A flows through the circuit. Calculate the resistance of the bulb

Discussion

1490.	Choose the statement which is not correct about an electric fuse.
Answer» Choose the statement which is not correct about an electric fuse.

Discussion

1491.	show the problems related to the calculations of the photons
Answer» show the problems related to the calculations of the photons

Discussion

1492.	4. What is adsorption type
Answer» 4. What is adsorption type

Discussion

1493.	What is the function of the split rings of an electric generators and also discuss the function of the brushes?
Answer» What is the function of the split rings of an electric generators and also discuss the function of the brushes?

Discussion

1494.	Find the binding energy of 5626Fe. Atomic mass of 56Fe is 55.9349 u and that of 1H is 1.00783 u. Mass of neutron = 1.00867 u.
Answer» Find the binding energy of $_{26}^{56} F e$ . Atomic mass of $^{56} F e$ is 55.9349 u and that of $^{1} H$ is 1.00783 u. Mass of neutron = 1.00867 u.

Discussion

1495.	If the radius of Earth contracts by 1%, mass being the same. What would be the effect on our weight?
Answer» If the radius of Earth contracts by 1%, mass being the same. What would be the effect on our weight?

Discussion

1496.	Current through wire XY of circuit shown is
Answer» Current through wire $XY$ of circuit shown is

Discussion

1497.	Two identical small bodies each of mass m and charge q are suspended from two strings each of length l from a fixed point. This whole system is taken into an orbiting artificial satellite, then find the tension in the strings
Answer» Two identical small bodies each of mass m and charge q are suspended from two strings each of length l from a fixed point. This whole system is taken into an orbiting artificial satellite, then find the tension in the strings

Discussion

1498.	The shiny outer surface of a hollow sphere of aluminium of radius 50 cm is to be used as a mirror : (a) What will be the focal length of this mirror ? (b) Which type of spherical mirror will it provide ? (c) State whether this spherical mirror will diverge or converge light rays.
Answer» The shiny outer surface of a hollow sphere of aluminium of radius 50 cm is to be used as a mirror : (a) What will be the focal length of this mirror ? (b) Which type of spherical mirror will it provide ? (c) State whether this spherical mirror will diverge or converge light rays.

Discussion

1499.	A force produces change in linear motion or translation motion of a body .What does the moment of a force do?
Answer» A force produces change in linear motion or translation motion of a body .What does the moment of a force do?

Discussion

1500.	If the angle of incidence is 30,What is the angle of deviation ?if the light ray falls on a wooden surface .
Answer» If the angle of incidence is 30,What is the angle of deviation ?if the light ray falls on a wooden surface .

Discussion

Explore topic-wise InterviewSolutions in .

Name the physical quantity whose unit is “electron volt”. Express 5.6 electron volt in terms of its SI unit.

A concave lens forms the image of a real object such that the distance between the object and image is 10 cm and the magnification produced is 1/4. The focal length of the lens will be :

If the key in the arrangement is taken out (the circuit is made open) and magnetic field lines are drawn over the horizontal plane ABCD, the lines are:

Use Huygens’ principle to arrive at Snell’s law using a plane wavefront and acrossa plane surface.

is the weak nuclear force inversely proportional to the macroscopic domain?

ntA: Voltage across a resistor decreases in the direction of current and increases opposite to the direction of current.n ntR: Voltage drop or gain across a capacitor depends on the direction of current.n ntn ntExplain the correct reason as well as how reason is incorrect.n ntn

What is the difference between resistivity and resistance.conductivity and conductance

a projectile is projected with a speed 10m/s at an angle θ with the horizontal.if the horizontal range is 10m,then θ is (g=10m/s^2

If there is always a small spacing between two bodies in contact with each other how is friction generated.?

24. The current reading of ammeter is i1 when k1 (only) is closed and i2 when k2 (only) is closed, then 1) i1i2 3) i1=i2 4) i1=\sqrt{}2i2

How did Benjamin Franklin invent the charges?

If α and β are the eccentric angles of the extremities of a focal chord of an ellipse, then the eccentricity of the ellipse is

A postage stamp kept below a rectangular glass slab of refractive index 1.5 when viewed from vertically above it, appears to be raised by 7.0 mm. Calculate the thickness of the glass slab.

97.Mechanism of beckmann rearrangement

A steady current is flowing in a cylindrical conductor.Is there any electric field within the conductor?

Calculate the energy radiated per minute from the filament of an incandescent lamp at 2000K if the surface area is 5×10^-5 m^2and its relative emittance is 0.85, sigma= 5.7×10^-8 MKS units

Question 8In the figure of the human eye, the cornea is represented by the letter.(a) A(b) B(c) C(d) D

Arrange the rays in electromagnetic spectrum according to the increasing order of wavelength. (1) Infrared rays, (2) X rays, (3) Radiowaves, (4) Microwaves, (5) Gamma rays, (6) UV rays.

The period of oscillation of a simple pendulum of length l suspended from the roof of a vehicle which moves without friction down an inclined plane of inclination α, is given by

6. For a concave mirror, paraxial rays are focused at distance R/2 from pole and marginal rays are focused atdistance x from pole, then (R is radius of curvature)

Describe and explain, how are normal I can see objects link at various distances clearly.

A rectangular glass slab ABCD, of refractive index n1, is immersed in water of refractive index n2 (n1&gt;n2). A ray of light in incident at the surface AB of the slab as shown. The maximum value of the angle of incidence amax, such that the ray comes out only from the other surface CD is given by

Let mp be the mass of a proton, mn the mass of a neutron, M1 is the mass of a 2010Ne nucleus &amp; M2 is the mass of a 4020Ca nucleus. Then

Skin cancer is caused by___rays.

For a particle (tied with massless string) to completemotion in a vertical circle of radius r, the minimumvelocity required at its lowest position is

In wireless communication how em waves carry messages how the message is coded

For a person, the distance of eye lens from the retina is 2.00 cm and maximum focal length of the eye lens is 1.96 cm. Find the far point of the person.

31.A block is kept on a horizontal table. The table is undergoing SHM of frequency 3Hz in a horizontal place. The coefficient of static friction between block and table surface is 0.72 . Find the Maximum amplitude of the table in such block doesn't slip on the surface

Calculate the current through a 60 W lamp rated for 250 V. If the line voltage falls to 200 V, how is the power consumed by the lamp affected?

A long staright wire carrying 5A current lies in the plane of the paper as shown in the given figure. Find the magnitude and direction of the magnetic field at point P. [Given μ0=4π×10−7Tm/A]

What does a rating of '916' on a gold ornament indicate?

Two identical cells whether joined together in series or in parallel give the same current, when connected to externalresistance of 2 . Their internal resistance r is

a simple pendulum of infinite length has infinite kinetic energy at mean position (so its velocity should be greater than escape velocity) then why it returns back?what is the force acting at extreme position i.e. infinity?

23.Why work done by external force is taken as positive and work done by Conservative electrostatic force is taken as negative

c) A bulb is connected to a battery of potential difference 4 V and internal resistance 2.50A steady current of 0.5 A flows through the circuit. Calculate the resistance of the bulb

Choose the statement which is not correct about an electric fuse.

show the problems related to the calculations of the photons

4. What is adsorption type

What is the function of the split rings of an electric generators and also discuss the function of the brushes?

Find the binding energy of 5626Fe. Atomic mass of 56Fe is 55.9349 u and that of 1H is 1.00783 u. Mass of neutron = 1.00867 u.

If the radius of Earth contracts by 1%, mass being the same. What would be the effect on our weight?

Current through wire XY of circuit shown is

Two identical small bodies each of mass m and charge q are suspended from two strings each of length l from a fixed point. This whole system is taken into an orbiting artificial satellite, then find the tension in the strings

The shiny outer surface of a hollow sphere of aluminium of radius 50 cm is to be used as a mirror : (a) What will be the focal length of this mirror ? (b) Which type of spherical mirror will it provide ? (c) State whether this spherical mirror will diverge or converge light rays.

A force produces change in linear motion or translation motion of a body .What does the moment of a force do?

If the angle of incidence is 30,What is the angle of deviation ?if the light ray falls on a wooden surface .

A rectangular glass slab ABCD, of refractive index n1, is immersed in water of refractive index n2 (n1>n2). A ray of light in incident at the surface AB of the slab as shown. The maximum value of the angle of incidence amax, such that the ray comes out only from the other surface CD is given by

Let mp be the mass of a proton, mn the mass of a neutron, M1 is the mass of a 2010Ne nucleus & M2 is the mass of a 4020Ca nucleus. Then