16569 + Interview Questions in Physics Page 11 InterviewSolution

501.	0 1/30 Three point masses m1, m2 and m3 are placed at the corners of a thinmassless rectangular sheet (1.2 m x 1.0 m) as shown. Centre of mass will belocated at the pointm 2.4 kg1.0 mm, 16 kgA 12 m B m, 2.0 kg
Answer» 0 1/30 Three point masses m1, m2 and m3 are placed at the corners of a thinmassless rectangular sheet (1.2 m x 1.0 m) as shown. Centre of mass will belocated at the pointm 2.4 kg1.0 mm, 16 kgA 12 m B m, 2.0 kg

Discussion

502.	Uniform linear motion is motion with a constant velocity (zero acceleration). Uniform circular motion is motion with___.
Answer» Uniform linear motion is motion with a constant velocity (zero acceleration). Uniform circular motion is motion with___.

Discussion

503.	The Laplace transform of tet is
Answer» The Laplace transform of $t e^{t}$ is

Discussion

504.	State whether the resistance of filament of a bulb will decrease, remain unchanged or increase when it glows.
Answer» State whether the resistance of filament of a bulb will decrease, remain unchanged or increase when it glows.

Discussion

505.	A ray is incident at an angle of incidence i on one surface of small angle prism (prism angle is A) and emerges normally from the opposite surface. The refractive index of material of prism is μ=2. The angle of incidence is nearly (consider incidence angle i small)
Answer» A ray is incident at an angle of incidence $i$ on one surface of small angle prism (prism angle is $A$ ) and emerges normally from the opposite surface. The refractive index of material of prism is $μ = 2$ . The angle of incidence is nearly (consider incidence angle $i$ small)

Discussion

506.	Why did Mr. Mullick turn down Patol Babu's request for a rehearsal?
Answer» Why did Mr. Mullick turn down Patol Babu's request for a rehearsal?

Discussion

507.	110.A coil having N turns is wound tightly in the form of a spiral with inner and outer radii a and b respectively. When a current I passes through the coil, the magnetic field at the centre is :
Answer» 110.A coil having N turns is wound tightly in the form of a spiral with inner and outer radii a and b respectively. When a current I passes through the coil, the magnetic field at the centre is :

Discussion

508.	An electric heater coil has a resistance of 500Ω. Calculate the time required by the coil to convert 20g of ice at -10oC to 20g of water at 0oC if a current of 50mA flows through it.
Answer» An electric heater coil has a resistance of 500Ω. Calculate the time required by the coil to convert 20g of ice at -10^oC to 20g of water at 0^oC if a current of 50mA flows through it.

Discussion

509.	What is the name of the process in which rainwater falling on the earth is stopped from flowing and made to percolate into the ground?
Answer» What is the name of the process in which rainwater falling on the earth is stopped from flowing and made to percolate into the ground?

Discussion

510.	Unpolarized light of intensity 32 Wm−2 passes through three polarisers such that the transmission axis of the last polariser is crossed with the first, if the intensity of the emerging light is 3 Wm−2, what is the angle between the transmission axes of the first two polarisers?
Answer» Unpolarized light of intensity $32 W m^{- 2}$ passes through three polarisers such that the transmission axis of the last polariser is crossed with the first, if the intensity of the emerging light is $3 W m^{- 2}$ , what is the angle between the transmission axes of the first two polarisers?

Discussion

511.	Sort the following electric components in the correct order from the mainline to an appliance of a household:
Answer» Sort the following electric components in the correct order from the mainline to an appliance of a household:

Discussion

512.	In the given picture, ring A at the bottom is positively charged. Ring B is brought and placed over it. Ring B hovers at a certain height above A. What could be the charge on ring B?
Answer» In the given picture, ring A at the bottom is positively charged. Ring B is brought and placed over it. Ring B hovers at a certain height above A. What could be the charge on ring B?

512.

In the given picture, ring A at the bottom is positively charged. Ring B is brought and placed over it. Ring B hovers at a certain height above A. What could be the charge on ring B?

Answer»

In the given picture, ring A at the bottom is positively charged. Ring B is brought and placed over it. Ring B hovers at a certain height above A. What could be the charge on ring B?

Discussion

513.	The equivalent resistance between A and B is:
Answer» The equivalent resistance between A and B is:

513.

The equivalent resistance between A and B is:

Answer»

The equivalent resistance between A and B is:

Discussion

514.	A 3 cm high object is placed at a distance of 80 cm from a concave lens of focal length 20 cm. Find the size of the image.
Answer» A $3 c m$ high object is placed at a distance of $80 c m$ from a concave lens of focal length $20 c m$ . Find the size of the image.

Discussion

515.	A square coil of side l carries a current I. It is kept on a smooth horizontal surface. A uniform magnetic field exists in the region, directed in the plane of the coil as shown in the figure. what should be the minimum value of B, so that the coil will start tipping over ? Mass of the coil is M and it has N number of turns.
Answer» A square coil of side $l$ carries a current $I$ . It is kept on a smooth horizontal surface. A uniform magnetic field exists in the region, directed in the plane of the coil as shown in the figure. what should be the minimum value of $B$ , so that the coil will start tipping over ? Mass of the coil is $M$ and it has $N$ number of turns.

Discussion

516.	28. A body of mass m is moving along a straight linefrom A to B with constant velocity v as shown. LetLA, LB be the magnitude of angular momentum atpoint A and B with respect to origin, thenAлш(0)(u)x817(1)81 (2)77 (e)(4) Nothing can be said
Answer» 28. A body of mass m is moving along a straight linefrom A to B with constant velocity v as shown. LetLA, LB be the magnitude of angular momentum atpoint A and B with respect to origin, thenAлш(0)(u)x817(1)81 (2)77 (e)(4) Nothing can be said

Discussion

517.	Distinguish between heat and temperature.
Answer» Distinguish between heat and temperature.

Discussion

518.	What is band madel
Answer» What is band madel

Discussion

519.	8. A metal crystallizes into 2 cubic phases fcc and BCC whose unit lens are 3.5 angstrom and 3.0 angstrom respectively.The ratio of densities of fcc and BCC is:- A)1.26 B) 1.75 C)2.10 D)1.90 1. X2Y 2. XY2 3.X4Y 4. XY
Answer» 8. A metal crystallizes into 2 cubic phases fcc and BCC whose unit lens are 3.5 angstrom and 3.0 angstrom respectively.The ratio of densities of fcc and BCC is:- A)1.26 B) 1.75 C)2.10 D)1.90 1. X2Y 2. XY2 3.X4Y 4. XY

Discussion

520.	5. What is the order of electrode potential of Alkali metals And also the order of reducing agent of alkali metals?
Answer» 5. What is the order of electrode potential of Alkali metals And also the order of reducing agent of alkali metals?

Discussion

521.	Two magnets of equal masses are joined at right angles to each other, as shown in the diagram. Magnet-1 has a magnetic moment √3 times that of magnet-2. This arrangement is pivoted so that it is free to rotate in the horizontal plane. Under equilibrium, what angle will the magent-1 subtend with the magnetic meridian?
Answer» Two magnets of equal masses are joined at right angles to each other, as shown in the diagram. Magnet- $1$ has a magnetic moment $\sqrt{3}$ times that of magnet- $2$ . This arrangement is pivoted so that it is free to rotate in the horizontal plane. Under equilibrium, what angle will the magent-1 subtend with the magnetic meridian?

Discussion

522.	A thin coverging lens is made up of glass of refractive index 1.5. It acts like a concave lens of focal length 50 cm, when immersed in a liquid of refractive index 158, focal length of converging lens in air (in metre) is
Answer» A thin coverging lens is made up of glass of refractive index $1.5$ . It acts like a concave lens of focal length $50 cm$ , when immersed in a liquid of refractive index $\frac{15}{8}$ , focal length of converging lens in air (in metre) is

Discussion

523.	Consider a block on rough horizontal surface. What is the minimum force required to move the block?Derive the equation or give reason for that equation.
Answer» Consider a block on rough horizontal surface. What is the minimum force required to move the block? Derive the equation or give reason for that equation.

Discussion

524.	If a mirror forms a real inverted image of same size then which of the following mirrors and position of object can be correct?
Answer» If a mirror forms a real inverted image of same size then which of the following mirrors and position of object can be correct?

Discussion

525.	How does an ammeter work and why is it connected in series?
Answer» How does an ammeter work and why is it connected in series?

Discussion

526.	For electricity to flow easily through a conductor what should be more or less Resistance or Resistivity of a conductor?
Answer» For electricity to flow easily through a conductor what should be more or less Resistance or Resistivity of a conductor?

Discussion

527.	Calculate the time required to pass a charge of 3.60 x 10^4 C through an electric circuit in which the current is 6.00 A.
Answer» Calculate the time required to pass a charge of 3.60 x 10^4 C through an electric circuit in which the current is 6.00 A.

Discussion

528.	A 20 kW, 6-pole, 50 Hz, 3-phase slip ring induction motor runs at 950 rpm on full load with a rotor current per phase of 38 A. Assuming 2 kW mechanical losses, the rotor resistance per phase (in ohms) is ________0.267
Answer» A 20 kW, 6-pole, 50 Hz, 3-phase slip ring induction motor runs at 950 rpm on full load with a rotor current per phase of 38 A. Assuming 2 kW mechanical losses, the rotor resistance per phase (in ohms) is ________ 0.267

Discussion

529.	If a light ray incidents normally on one of the faces of the prism of refractive index 2 and the emergent ray just grazes the second face of the prism then angle the angle of deviation i
Answer» If a light ray incidents normally on one of the faces of the prism of refractive index 2 and the emergent ray just grazes the second face of the prism then angle the angle of deviation i

Discussion

530.	Tension in an massless string acts on two sides both in d upward and downward direction then why they does not x cancel out each other because they are opposite in directi.
Answer» Tension in an massless string acts on two sides both in d upward and downward direction then why they does not x cancel out each other because they are opposite in directi.

Discussion

531.	State the laws:(1) Ohm’s law(2) Joule’s law
Answer» State the laws: (1) Ohm’s law (2) Joule’s law

531.

State the laws:(1) Ohm’s law(2) Joule’s law

Answer»

State the laws:

(1) Ohm’s law

(2) Joule’s law

Discussion

532.	Number of electrons in a conductor of area of cross section 0.4 m2 is 1023 m−3. If the drift velocity of the electrons is 4×10−5 ms−1, what is the current flowing through the conductor in ampere? (Take electron charge as 1.6×10−19 C)0.256
Answer» Number of electrons in a conductor of area of cross section $0.4 m^{2}$ is $10^{23} m^{- 3}$ . If the drift velocity of the electrons is $4 \times 10^{- 5} m s^{- 1}$ , what is the current flowing through the conductor in ampere? (Take electron charge as $1.6 \times 10^{- 19} C$ ) 0.256

Discussion

533.	Though a woman can see the distant objects clearly, she cannot see the nearby objects clearly. She is suffering from the defect of vision called ? (a) long-sight (b) short-sight (c) hind-sight (d) mid-sight
Answer» Though a woman can see the distant objects clearly, she cannot see the nearby objects clearly. She is suffering from the defect of vision called ? (a) long-sight (b) short-sight (c) hind-sight (d) mid-sight

Discussion

534.	An object of size 10 cm is placed at a distance of 30 cm from a concave mirror of focal length 20 cm. The size of the image formed is -
Answer» An object of size $10 cm$ is placed at a distance of $30 cm$ from a concave mirror of focal length $20 cm$ . The size of the image formed is -

Discussion

535.	When a magnet is kept on a table and a compass is taken close to it, it points in a certain direction at every point near the magnet. When the points are joined, we obtain certain lines. Choose the correct statement(s) regarding the lines1. The closer they are, the stronger the magnet.2. They are imaginary lines which have a particular direction.
Answer» When a magnet is kept on a table and a compass is taken close to it, it points in a certain direction at every point near the magnet. When the points are joined, we obtain certain lines. Choose the correct statement(s) regarding the lines 1. The closer they are, the stronger the magnet. 2. They are imaginary lines which have a particular direction.

Discussion

536.	Which of the following is the correct set-up of a circuit?
Answer» Which of the following is the correct set-up of a circuit?

Discussion

537.	Which has more power : a thick convex lens or a thin convex lens, made of the same glass ? Give reason for your choice.
Answer» Which has more power : a thick convex lens or a thin convex lens, made of the same glass ? Give reason for your choice.

Discussion

538.	Through what process power generation happens in thermal power plants?
Answer» Through what process power generation happens in thermal power plants?

Discussion

539.	In groups of four discuss what you think happens next in the poem. Share your views with the rest of the class.
Answer» In groups of four discuss what you think happens next in the poem. Share your views with the rest of the class.

Discussion

540.	Two similar thin equi convex lenses of focal length f each are kept coaxiallyin contact with each other such that the focal length of the combination is F1 when the space between the two lenses is filled with glycerine (which has the same refractive index (μ=1.5) as that of glass ) then the equivalent focal length is F2 the rati
Answer» Two similar thin equi convex lenses of focal length f each are kept coaxiallyin contact with each other such that the focal length of the combination is F1 when the space between the two lenses is filled with glycerine (which has the same refractive index (μ=1.5) as that of glass ) then the equivalent focal length is F2 the rati

Discussion

541.	Figure 3.34 shows a potentiometer circuit for comparison of two resistances. The balance point with a standard resistor R = 10.0 Ω is found to be 58.3 cm, while that with the unknown resistance X is 68.5 cm. Determine the value of X . What might you do if you failed to find a balance point with the given cell of emf ε ?
Answer» Figure 3.34 shows a potentiometer circuit for comparison of two resistances. The balance point with a standard resistor R = 10.0 Ω is found to be 58.3 cm, while that with the unknown resistance X is 68.5 cm. Determine the value of X . What might you do if you failed to find a balance point with the given cell of emf ε ?

Discussion

542.	32. A rod of mass M and length L is suspended with the help of 2 light strings A and B as shown in the figure. Find the tension in string A
Answer» 32. A rod of mass M and length L is suspended with the help of 2 light strings A and B as shown in the figure. Find the tension in string A

Discussion

543.	State the source of centripetal force that a planet requires to revolve around the sun. On what factors does that force depend ? Suppose this force suddenly becomes zero, then in which direction will the planet begin to move if no other celestial body affects it ?
Answer» State the source of centripetal force that a planet requires to revolve around the sun. On what factors does that force depend ? Suppose this force suddenly becomes zero, then in which direction will the planet begin to move if no other celestial body affects it ?

Discussion

544.	Consider a simple RC circuit as shown in Figure 1Process 1 : In the circuit the switch S is closed at t=0 and the capacitor is fully charged to voltage Ve (i.e. charging continues for time T>>RC ). In the process some dissipation (ED) occurs across the resistance R. The amount of energy finally stored in the fully charged capacitor is Ec.Process 2 : In a different process the voltage is first set to V03 and maintained for a charging time T>>RC. Then the voltage is raised to 2V03 without discharging the capacitor and again maintained for a time T>>RC. The process is repeated one more time by raising the voltage to V0 and the capacitor is charged to the same final voltage V0 as in Process 1.These two processes are depicted in Figure 2.In Process 2, total energy dissipated across the resistance ED is
Answer» Consider a simple RC circuit as shown in Figure 1 Process 1 : In the circuit the switch $S$ is closed at $t = 0$ and the capacitor is fully charged to voltage $V_{e}$ (i.e. charging continues for time $T >> R C$ ). In the process some dissipation ( $E_{D}$ ) occurs across the resistance R. The amount of energy finally stored in the fully charged capacitor is $E_{c}$ . Process 2 : In a different process the voltage is first set to $\frac{V_{0}}{3}$ and maintained for a charging time T>>RC. Then the voltage is raised to $\frac{2 V_{0}}{3}$ without discharging the capacitor and again maintained for a time $T >> R C$ . The process is repeated one more time by raising the voltage to $V_{0}$ and the capacitor is charged to the same final voltage $V_{0}$ as in Process $1 .$ These two processes are depicted in Figure 2. In Process $2,$ total energy dissipated across the resistance $E_{D}$ is

544.

Consider a simple RC circuit as shown in Figure 1Process 1 : In the circuit the switch S is closed at t=0 and the capacitor is fully charged to voltage Ve (i.e. charging continues for time T>>RC ). In the process some dissipation (ED) occurs across the resistance R. The amount of energy finally stored in the fully charged capacitor is Ec.Process 2 : In a different process the voltage is first set to V03 and maintained for a charging time T>>RC. Then the voltage is raised to 2V03 without discharging the capacitor and again maintained for a time T>>RC. The process is repeated one more time by raising the voltage to V0 and the capacitor is charged to the same final voltage V0 as in Process 1.These two processes are depicted in Figure 2.In Process 2, total energy dissipated across the resistance ED is

Answer»

Consider a simple RC circuit as shown in Figure 1

Process 1 : In the circuit the switch $S$ is closed at $t = 0$ and the capacitor is fully charged to voltage $V_{e}$ (i.e. charging continues for time $T >> R C$ ). In the process some dissipation ( $E_{D}$ ) occurs across the resistance R. The amount of energy finally stored in the fully charged capacitor is $E_{c}$ .

Process 2 :

In a different process the voltage is first set to $\frac{V_{0}}{3}$ and maintained for a charging time T>>RC. Then the voltage is raised to $\frac{2 V_{0}}{3}$ without discharging the capacitor and again maintained for a time $T >> R C$ . The process is repeated one more time by raising the voltage to $V_{0}$ and the capacitor is charged to the same final voltage $V_{0}$ as in Process $1 .$

These two processes are depicted in Figure 2.

In Process $2,$ total energy dissipated across the resistance $E_{D}$ is

Discussion

545.	An astronomical telescope has an angular magnification of magnitude of 5 for distant objects. The length of a telescope is 36 cm. The focal lengths of its objective and eye piece can be-
Answer» An astronomical telescope has an angular magnification of magnitude of $5$ for distant objects. The length of a telescope is $36 cm.$ The focal lengths of its objective and eye piece can be-

Discussion

546.	1calorie = ?
Answer» 1calorie = ?

Discussion

547.	List some properties of magnetic lines of force around a bar magnet.
Answer» List some properties of magnetic lines of force around a bar magnet.

Discussion

548.	assuming human pupil to have a radius of 0.25 cm and taken for comfortable viewing dis†an ces of 25cm .the minimum separation between two objects that human eye can resolve at 500 nm wavelength is
Answer» assuming human pupil to have a radius of 0.25 cm and taken for comfortable viewing dis†an ces of 25cm .the minimum separation between two objects that human eye can resolve at 500 nm wavelength is

Discussion

549.	The media can help by______________________
Answer» The media can help by______________________

Discussion

550.	(a) What do you understand by the " resistivity" of a substance (b) A wire is 1.0 m long, 0.2 mm in diameter and has a resistance of 10 Ω Calculate the resistivity of its material?
Answer» (a) What do you understand by the " resistivity" of a substance (b) A wire is 1.0 m long, 0.2 mm in diameter and has a resistance of 10 $Ω$ Calculate the resistivity of its material?

Discussion

Explore topic-wise InterviewSolutions in .

0 1/30 Three point masses m1, m2 and m3 are placed at the corners of a thinmassless rectangular sheet (1.2 m x 1.0 m) as shown. Centre of mass will belocated at the pointm 2.4 kg1.0 mm, 16 kgA 12 m B m, 2.0 kg

Uniform linear motion is motion with a constant velocity (zero acceleration). Uniform circular motion is motion with___.

The Laplace transform of tet is

State whether the resistance of filament of a bulb will decrease, remain unchanged or increase when it glows.

A ray is incident at an angle of incidence i on one surface of small angle prism (prism angle is A) and emerges normally from the opposite surface. The refractive index of material of prism is μ=2. The angle of incidence is nearly (consider incidence angle i small)

Why did Mr. Mullick turn down Patol Babu's request for a rehearsal?

110.A coil having N turns is wound tightly in the form of a spiral with inner and outer radii a and b respectively. When a current I passes through the coil, the magnetic field at the centre is :

An electric heater coil has a resistance of 500Ω. Calculate the time required by the coil to convert 20g of ice at -10oC to 20g of water at 0oC if a current of 50mA flows through it.

What is the name of the process in which rainwater falling on the earth is stopped from flowing and made to percolate into the ground?

Unpolarized light of intensity 32 Wm−2 passes through three polarisers such that the transmission axis of the last polariser is crossed with the first, if the intensity of the emerging light is 3 Wm−2, what is the angle between the transmission axes of the first two polarisers?

Sort the following electric components in the correct order from the mainline to an appliance of a household:

In the given picture, ring A at the bottom is positively charged. Ring B is brought and placed over it. Ring B hovers at a certain height above A. What could be the charge on ring B?

The equivalent resistance between A and B is:

A 3 cm high object is placed at a distance of 80 cm from a concave lens of focal length 20 cm. Find the size of the image.

28. A body of mass m is moving along a straight linefrom A to B with constant velocity v as shown. LetLA, LB be the magnitude of angular momentum atpoint A and B with respect to origin, thenAлш(0)(u)x817(1)81 (2)77 (e)(4) Nothing can be said

Distinguish between heat and temperature.

What is band madel

8. A metal crystallizes into 2 cubic phases fcc and BCC whose unit lens are 3.5 angstrom and 3.0 angstrom respectively.The ratio of densities of fcc and BCC is:- A)1.26 B) 1.75 C)2.10 D)1.90 1. X2Y 2. XY2 3.X4Y 4. XY

5. What is the order of electrode potential of Alkali metals And also the order of reducing agent of alkali metals?

A thin coverging lens is made up of glass of refractive index 1.5. It acts like a concave lens of focal length 50 cm, when immersed in a liquid of refractive index 158, focal length of converging lens in air (in metre) is

Consider a block on rough horizontal surface. What is the minimum force required to move the block?Derive the equation or give reason for that equation.

If a mirror forms a real inverted image of same size then which of the following mirrors and position of object can be correct?

How does an ammeter work and why is it connected in series?

For electricity to flow easily through a conductor what should be more or less Resistance or Resistivity of a conductor?

Calculate the time required to pass a charge of 3.60 x 10^4 C through an electric circuit in which the current is 6.00 A.

A 20 kW, 6-pole, 50 Hz, 3-phase slip ring induction motor runs at 950 rpm on full load with a rotor current per phase of 38 A. Assuming 2 kW mechanical losses, the rotor resistance per phase (in ohms) is ________0.267

If a light ray incidents normally on one of the faces of the prism of refractive index 2 and the emergent ray just grazes the second face of the prism then angle the angle of deviation i

Tension in an massless string acts on two sides both in d upward and downward direction then why they does not x cancel out each other because they are opposite in directi.

State the laws:(1) Ohm’s law(2) Joule’s law

Number of electrons in a conductor of area of cross section 0.4 m2 is 1023 m−3. If the drift velocity of the electrons is 4×10−5 ms−1, what is the current flowing through the conductor in ampere? (Take electron charge as 1.6×10−19 C)0.256

Though a woman can see the distant objects clearly, she cannot see the nearby objects clearly. She is suffering from the defect of vision called ? (a) long-sight (b) short-sight (c) hind-sight (d) mid-sight

An object of size 10 cm is placed at a distance of 30 cm from a concave mirror of focal length 20 cm. The size of the image formed is -

Which of the following is the correct set-up of a circuit?

Which has more power : a thick convex lens or a thin convex lens, made of the same glass ? Give reason for your choice.

Through what process power generation happens in thermal power plants?

In groups of four discuss what you think happens next in the poem. Share your views with the rest of the class.

32. A rod of mass M and length L is suspended with the help of 2 light strings A and B as shown in the figure. Find the tension in string A

State the source of centripetal force that a planet requires to revolve around the sun. On what factors does that force depend ? Suppose this force suddenly becomes zero, then in which direction will the planet begin to move if no other celestial body affects it ?

An astronomical telescope has an angular magnification of magnitude of 5 for distant objects. The length of a telescope is 36 cm. The focal lengths of its objective and eye piece can be-

1calorie = ?

List some properties of magnetic lines of force around a bar magnet.

assuming human pupil to have a radius of 0.25 cm and taken for comfortable viewing dis†an ces of 25cm .the minimum separation between two objects that human eye can resolve at 500 nm wavelength is

The media can help by______________________

(a) What do you understand by the " resistivity" of a substance (b) A wire is 1.0 m long, 0.2 mm in diameter and has a resistance of 10 Ω Calculate the resistivity of its material?