16569 + Interview Questions in Physics Page 38 InterviewSolution

1851.	The refractive index of diamond is 2.42 what is the meaning of this statement in relation to the speed of light.
Answer» The refractive index of diamond is 2.42 what is the meaning of this statement in relation to the speed of light.

Discussion

1852.	The intensity of X-rays of wavelength 0.5 Angstrom reduces to one fourth on passing through 3.5 mm thickness of a metal foil. The coefficient of absorption of metal will be- (1) 0.2 mm^-1 (2) 0.3 mm^-1 (3) 0.4 mm^-1 (4) 0.5 mm^-1
Answer» The intensity of X-rays of wavelength 0.5 Angstrom reduces to one fourth on passing through 3.5 mm thickness of a metal foil. The coefficient of absorption of metal will be- (1) 0.2 mm^-1 (2) 0.3 mm^-1 (3) 0.4 mm^-1 (4) 0.5 mm^-1

Discussion

1853.	You have been gifted a new cell phone which is powered by solar energy.Write an email to your friend describing the phone and all its exciting features. You may use the notes that you have made in A.7
Answer» You have been gifted a new cell phone which is powered by solar energy. Write an email to your friend describing the phone and all its exciting features. You may use the notes that you have made in A.7

1853.

You have been gifted a new cell phone which is powered by solar energy.Write an email to your friend describing the phone and all its exciting features. You may use the notes that you have made in A.7

Answer»

You have been gifted a new cell phone which is powered by solar energy.

Write an email to your friend describing the phone and all its exciting features. You may use the notes that you have made in A.7

Discussion

1854.	for three resis†an ce of .5 oham each are connected in series with a 12 volt power supply. a.calculate the total resis†an ce. b. calculate the current flowing through the circuit. c.calculate the potential difference across each resistor .
Answer» for three resis†an ce of .5 oham each are connected in series with a 12 volt power supply. a.calculate the total resis†an ce. b. calculate the current flowing through the circuit. c.calculate the potential difference across each resistor .

Discussion

1855.	If I build a turbine in a fast flowing stream of the river without building a dam. What energy conversion will happen for power generation?
Answer» If I build a turbine in a fast flowing stream of the river without building a dam. What energy conversion will happen for power generation?

Discussion

1856.	If the potential difference between points A and B at a certain instant is 12 V, the potential difference between A and C at the same instant will be -
Answer» If the potential difference between points $A$ and $B$ at a certain instant is $12 V$ , the potential difference between $A$ and $C$ at the same instant will be -

Discussion

1857.	State the changes in the position, size and nature of the image when the object is brought from infinity up to the convex lens. Illustrate your answer by drawing the ray diagrams.
Answer» State the changes in the position, size and nature of the image when the object is brought from infinity up to the convex lens. Illustrate your answer by drawing the ray diagrams.

Discussion

1858.	An object is placed at 30 cm in front of the convex lens of focal length 10 cm. Find out the image distance from the lens?
Answer» An object is placed at $30 c m$ in front of the convex lens of focal length $10 c m$ . Find out the image distance from the lens?

Discussion

1859.	On the basis of the four positions of a dice given below find the colour of the face opposite ‘Yellow’.
Answer» On the basis of the four positions of a dice given below find the colour of the face opposite ‘Yellow’.

1859.

On the basis of the four positions of a dice given below find the colour of the face opposite ‘Yellow’.

Answer»

On the basis of the four positions of a dice given below find the colour of the face opposite ‘Yellow’.

Discussion

1860.	Two students made box-type solar cookers separately. They both painted the insulated box with black colour from inside, the cooking pots were painted black from outside, and a plane mirror reflector was also attached. One of the students covered the solar cooker box with a transparent glass sheet but the other student covered the solar cooker box with a transparent plastic sheet. Which of the two solar cookers will be more efficient and why?
Answer» Two students made box-type solar cookers separately. They both painted the insulated box with black colour from inside, the cooking pots were painted black from outside, and a plane mirror reflector was also attached. One of the students covered the solar cooker box with a transparent glass sheet but the other student covered the solar cooker box with a transparent plastic sheet. Which of the two solar cookers will be more efficient and why?

Discussion

1861.	17.A monkey can jump a maximum horizontal distance of 2o m then find the velocity of monkey?
Answer» 17.A monkey can jump a maximum horizontal distance of 2o m then find the velocity of monkey?

Discussion

1862.	How much solar energy will be received by 125 meter square area on earth’s surface in eight hours if the solar constant is 1.4 kilowatt per square meter?
Answer» How much solar energy will be received by 125 meter square area on earth’s surface in eight hours if the solar constant is 1.4 kilowatt per square meter?

Discussion

1863.	To an observer on Earth the stars appear to twinkle. This is due to
Answer» To an observer on Earth the stars appear to twinkle. This is due to

Discussion

1864.	Which satellite is used specifically for managing the natural resources of the nation?
Answer» Which satellite is used specifically for managing the natural resources of the nation?

Discussion

1865.	If all rays falling on a convex mirror are parallel to the principal axis of the mirror, what happens to them after reflection from the mirror?
Answer» If all rays falling on a convex mirror are parallel to the principal axis of the mirror, what happens to them after reflection from the mirror?

Discussion

1866.	a 10 m long potentiometer wire has a potential gradient of 0.0025 V/cm along its length.calculate the lenghth of the wire at which null point is obtained for a 1.025 V s†an dard cell. also find the emf of another cell for which the null point is obtained st 860 cm lenghth.what maximum PD can be measured by this potentiometer
Answer» a 10 m long potentiometer wire has a potential gradient of 0.0025 V/cm along its length.calculate the lenghth of the wire at which null point is obtained for a 1.025 V s†an dard cell. also find the emf of another cell for which the null point is obtained st 860 cm lenghth.what maximum PD can be measured by this potentiometer

Discussion

1867.	The wires in a domestic circuit which are at the same potential are:
Answer» The wires in a domestic circuit which are at the same potential are:

Discussion

1868.	An observer stands at a distance of 850 m from the cliff and fires a gun. After what time will he hear the echo if sound travels at a speed of 350 ms−1 in air?
Answer» An observer stands at a distance of 850 m from the cliff and fires a gun. After what time will he hear the echo if sound travels at a speed of $350 m s^{- 1}$ in air?

Discussion

1869.

Name Age Year of becoming an astronaut No. of space Journeys Experience with zero gravity Ways of staying fit Memorable moments What one has learnt from the travels Peggy hitson

Answer»

Name	Age	Year of becoming an astronaut	No. of space Journeys	Experience with zero gravity	Ways of staying fit	Memorable moments	What one has learnt from the travels
Peggy hitson

Discussion

1870.	Handles of tools such as screwdrivers and pliers used by electricians for repair work usually have plastic or rubber cover on them. Can you explain why?
Answer» Handles of tools such as screwdrivers and pliers used by electricians for repair work usually have plastic or rubber cover on them. Can you explain why?

Discussion

1871.	Match the following mirrors with their correct name i) Convex ii) Plane iii) Parabolic iv) Concave
Answer» Match the following mirrors with their correct name i) Convex ii) Plane iii) Parabolic iv) Concave

Discussion

1872.	what is wattless current and choke coil?
Answer» what is wattless current and choke coil?

Discussion

1873.	19 A solution of sucrose in 100g of water boils at 100.25C. If this solution is boiled till its temperature is 101C, the mass of water evaporated from the solution is A 25g B 50g C 75g D 85g
Answer» 19 A solution of sucrose in 100g of water boils at 100.25C. If this solution is boiled till its temperature is 101C, the mass of water evaporated from the solution is A 25g B 50g C 75g D 85g

Discussion

1874.	There is a straight wire carrying current as shown in the figure. What is the direction of the magnetic field around the wire when the reference point is above the wire?
Answer» There is a straight wire carrying current as shown in the figure. What is the direction of the magnetic field around the wire when the reference point is above the wire?

1874.

There is a straight wire carrying current as shown in the figure. What is the direction of the magnetic field around the wire when the reference point is above the wire?

Answer»

There is a straight wire carrying current as shown in the figure. What is the direction of the magnetic field around the wire when the reference point is above the wire?

Discussion

1875.	What is the function of rods and cone cells?
Answer» What is the function of rods and cone cells?

Discussion

1876.	A molten metal of mass 150 g is kept at its melting point 800oC. When it is allowed to freeze at the same temperature, it gives out 75,000 J of heat energy. (a) What is the specific latent heat of the metal ? (b) If the specific heat capacity of metal is 200 J kg−1 K−1, how much additional heat energy will the metal give out in cooling to −50o C ?
Answer» A molten metal of mass 150 g is kept at its melting point $800^{o} C$ . When it is allowed to freeze at the same temperature, it gives out 75,000 J of heat energy. (a) What is the specific latent heat of the metal ? (b) If the specific heat capacity of metal is $200 J k g^{- 1} K^{- 1}$ , how much additional heat energy will the metal give out in cooling to $- 50^{o} C$ ?

1876.

A molten metal of mass 150 g is kept at its melting point 800oC. When it is allowed to freeze at the same temperature, it gives out 75,000 J of heat energy. (a) What is the specific latent heat of the metal ? (b) If the specific heat capacity of metal is 200 J kg−1 K−1, how much additional heat energy will the metal give out in cooling to −50o C ?

Answer»

A molten metal of mass 150 g is kept at its melting point $800^{o} C$ . When it is allowed to freeze at the same temperature, it gives out 75,000 J of heat energy.

(a) What is the specific latent heat of the metal ?

(b) If the specific heat capacity of metal is $200 J k g^{- 1} K^{- 1}$ , how much additional heat energy will the metal give out in cooling to $- 50^{o} C$ ?

Discussion

1877.	the escape velocity from the earth is 11.2 km/s the mass of another planet is 100 times of mass of earth and its radius is 4 times the radius of earth.the escape velocity for the planet is
Answer» the escape velocity from the earth is 11.2 km/s the mass of another planet is 100 times of mass of earth and its radius is 4 times the radius of earth.the escape velocity for the planet is

Discussion

1878.	Two charged particles having charges q1 and q2 and masses m1 and m2 are projected with the same velocity in a region of uniform magnetic field. They follow the trajectory as shownIt can be concluded that
Answer» Two charged particles having charges $q_{1} a n d q_{2}$ and masses $m_{1} a n d m_{2}$ are projected with the same velocity in a region of uniform magnetic field. They follow the trajectory as shown It can be concluded that

Discussion

1879.	in a house individual power of two elements are 100w amd 150w effective power of their series will be
Answer» in a house individual power of two elements are 100w amd 150w effective power of their series will be

Discussion

1880.	Define potential bareer in npn semiconductor
Answer» Define potential bareer in npn semiconductor

Discussion

1881.

The values of current I flowing in a given resistor for the corresponding values of potential difference V across the resistor are given below − I (amperes ) 0.5 1.0 2.0 3.0 4.0 V (volts) 1.6 3.4 6.7 10.2 13.2 Plot a graph between V and I and calculate the resistance of that resistor.

Answer»

The values of current I flowing in a given resistor for the corresponding values of potential difference V across the resistor are given below −

I (amperes )	0.5	1.0	2.0	3.0	4.0
V (volts)	1.6	3.4	6.7	10.2	13.2

Plot a graph between V and I and calculate the resistance of that resistor.

Discussion

1882.	Why does the eye need to change the focal length of the eye lens?
Answer» Why does the eye need to change the focal length of the eye lens?

Discussion

1883.	Why are environmentalists insisting upon 'sustainable natural resource management? Give any three reasons.
Answer» Why are environmentalists insisting upon 'sustainable natural resource management? Give any three reasons.

Discussion

1884.	The repeated reflections that result in the persistence of sound is called___.
Answer» The repeated reflections that result in the persistence of sound is called___.

Discussion

1885.	State True or False. If false correct it.(1) The SI unit of charge is volt.(2) Voltmeter is always connected in series with the device.(3) The conventional direction of flow of current is from positive terminal to negative terminal of the cell.(4) Silver and copper are good conductors.(5) Resistivity of pure metal is more than alloys.(6) The electric bulb consists of the filament whose melting point is low.
Answer» State True or False. If false correct it. (1) The SI unit of charge is volt. (2) Voltmeter is always connected in series with the device. (3) The conventional direction of flow of current is from positive terminal to negative terminal of the cell. (4) Silver and copper are good conductors. (5) Resistivity of pure metal is more than alloys. (6) The electric bulb consists of the filament whose melting point is low.

1885.

State True or False. If false correct it.(1) The SI unit of charge is volt.(2) Voltmeter is always connected in series with the device.(3) The conventional direction of flow of current is from positive terminal to negative terminal of the cell.(4) Silver and copper are good conductors.(5) Resistivity of pure metal is more than alloys.(6) The electric bulb consists of the filament whose melting point is low.

Answer»

State True or False. If false correct it.

(1) The SI unit of charge is volt.

(2) Voltmeter is always connected in series with the device.

(3) The conventional direction of flow of current is from positive terminal to negative terminal of the cell.

(4) Silver and copper are good conductors.

(5) Resistivity of pure metal is more than alloys.

(6) The electric bulb consists of the filament whose melting point is low.

Discussion

1886.	A current carrying conductor of mass 50 gm, length 0.5 m carrying a current of 1 A hangs by two identical springs each of spring constant 50 N/m as shown in the figure below. If an outwards uniform magnetic field of 1 T is applied on the conductor then the deformation in each spring will be (g=10 ms−2)
Answer» A current carrying conductor of mass $50 gm$ , length $0.5 m$ carrying a current of $1 A$ hangs by two identical springs each of spring constant $50 N/m$ as shown in the figure below. If an outwards uniform magnetic field of $1 T$ is applied on the conductor then the deformation in each spring will be ( $g = 10 {ms}^{- 2})$

Discussion

1887.	A 4 m long rod of negligible weight is supported at a point 125 cm from its one end and a load of 18 kgf is suspended at a point 60 cm from the support on the shorter arm. (a) if a weight W is placed at a distance of 250 cm from the support on the longer arm, find W. (b) If a weight 5 kgf is kept to balance the rod, find the position. (c) To which class of lever does it belong ?
Answer» A 4 m long rod of negligible weight is supported at a point 125 cm from its one end and a load of 18 kgf is suspended at a point 60 cm from the support on the shorter arm. (a) if a weight W is placed at a distance of 250 cm from the support on the longer arm, find W. (b) If a weight 5 kgf is kept to balance the rod, find the position. (c) To which class of lever does it belong ?

1887.

A 4 m long rod of negligible weight is supported at a point 125 cm from its one end and a load of 18 kgf is suspended at a point 60 cm from the support on the shorter arm. (a) if a weight W is placed at a distance of 250 cm from the support on the longer arm, find W. (b) If a weight 5 kgf is kept to balance the rod, find the position. (c) To which class of lever does it belong ?

Answer»

A 4 m long rod of negligible weight is supported at a point 125 cm from its one end and a load of 18 kgf is suspended at a point 60 cm from the support on the shorter arm.

(a) if a weight W is placed at a distance of 250 cm from the support on the longer arm, find W.

(b) If a weight 5 kgf is kept to balance the rod, find the position.

(c) To which class of lever does it belong ?

Discussion

1888.	In an experiment to determine the emf E2 of an unknown cell, its emf is compared with a standard cell of known emf E1=1.12 V. The balance point is obtained at 56 cm with the standard cell and 80 cm with the unknown cell. Determine the emf of the unknown cell.
Answer» In an experiment to determine the emf $E_{2}$ of an unknown cell, its emf is compared with a standard cell of known emf $E_{1} = 1.12 V$ . The balance point is obtained at $56 cm$ with the standard cell and $80 cm$ with the unknown cell. Determine the emf of the unknown cell.

Discussion

1889.	What is the principal of AC motor and DC motor
Answer» What is the principal of AC motor and DC motor

Discussion

1890.	A radio isotope ′X′ with a half-life 1.4×109 years decays to ′Y′ which is stable. A sample of the rock from a cave was found to contain ′X′ and ′Y′ in the ratio 1:7. The age of the rock is
Answer» A radio isotope $^{'} X^{'}$ with a half-life $1.4 \times 10^{9}$ years decays to $^{'} Y^{'}$ which is stable. A sample of the rock from a cave was found to contain $^{'} X^{'}$ and $^{'} Y^{'}$ in the ratio $1 : 7.$ The age of the rock is

Discussion

1891.	A telescope has an objective lens of focal length 200cm and an eye piece with focal length 2cm. If this telescope is used to see a 50m tall building at a distance of 2km, what is the height of the image of the building formed by the objective lens?
Answer» A telescope has an objective lens of focal length 200cm and an eye piece with focal length 2cm. If this telescope is used to see a 50m tall building at a distance of 2km, what is the height of the image of the building formed by the objective lens?

Discussion

1892.	44. Why is electron gain enthalpy for alkali metals negative
Answer» 44. Why is electron gain enthalpy for alkali metals negative

Discussion

1893.	a wire of resistivity is streched 3 times its original length. what would be its new resistivity?
Answer» a wire of resistivity is streched 3 times its original length. what would be its new resistivity?

Discussion

1894.	If there is no gravitational force acting on an orbiting satellite,then why do we say that in an orbiting satellite,the required centripetal force is provided by the gravitational force and if this force vanishes then satellite would not be able to revolve in a circular motion?
Answer» If there is no gravitational force acting on an orbiting satellite,then why do we say that in an orbiting satellite,the required centripetal force is provided by the gravitational force and if this force vanishes then satellite would not be able to revolve in a circular motion?

Discussion

1895.	Can 1 M NiSO4 be stored in a vessel made up of copper? E†extdegree_{Ni^{2+}/Ni}=-1.20 V and E†extdegree_{Cu^{2+}/Cu }= 0.34V.
Answer» Can 1 M NiSO4 be stored in a vessel made up of copper? E†extdegree_{Ni^{2+}/Ni}=-1.20 V and E†extdegree_{Cu^{2+}/Cu }= 0.34V.

Discussion

1896.	ntIn a wave travelling along x-axis the displacement of particles is given by z=Asink(x-2) at t=1sec where x is in metre. Also displacement of particle is z=Asink(x+3) at t=2sec find the velocity of waven
Answer» ntIn a wave travelling along x-axis the displacement of particles is given by z=Asink(x-2) at t=1sec where x is in metre. Also displacement of particle is z=Asink(x+3) at t=2sec find the velocity of waven

Discussion

1897.	In which direction does the wire move if the current flows through the wire in the downward direction?
Answer» In which direction does the wire move if the current flows through the wire in the downward direction?

Discussion

1898.	Answer the following questions:(a) What is total internal reflection?(b) State two conditions necessary for the total internal reflection to occur.(c) Draw diagrams to illustrate the total internal reflection.
Answer» Answer the following questions: (a) What is total internal reflection? (b) State two conditions necessary for the total internal reflection to occur. (c) Draw diagrams to illustrate the total internal reflection.

Discussion

1899.	In a conductor if Q charges flow through it, in time t is the correct relation between electric current(I), charge and time.
Answer» In a conductor if Q charges flow through it, in time t is the correct relation between electric current(I), charge and time.

Discussion

1900.	Calculate the equivalent resistance of two resistors having resistances 3 Ω and 6 Ω connected in parallel.
Answer» Calculate the equivalent resistance of two resistors having resistances $3 Ω$ and $6 Ω$ connected in parallel.

Discussion

Explore topic-wise InterviewSolutions in .

The refractive index of diamond is 2.42 what is the meaning of this statement in relation to the speed of light.

The intensity of X-rays of wavelength 0.5 Angstrom reduces to one fourth on passing through 3.5 mm thickness of a metal foil. The coefficient of absorption of metal will be- (1) 0.2 mm^-1 (2) 0.3 mm^-1 (3) 0.4 mm^-1 (4) 0.5 mm^-1

You have been gifted a new cell phone which is powered by solar energy.Write an email to your friend describing the phone and all its exciting features. You may use the notes that you have made in A.7

for three resis†an ce of .5 oham each are connected in series with a 12 volt power supply. a.calculate the total resis†an ce. b. calculate the current flowing through the circuit. c.calculate the potential difference across each resistor .

If I build a turbine in a fast flowing stream of the river without building a dam. What energy conversion will happen for power generation?

If the potential difference between points A and B at a certain instant is 12 V, the potential difference between A and C at the same instant will be -

State the changes in the position, size and nature of the image when the object is brought from infinity up to the convex lens. Illustrate your answer by drawing the ray diagrams.

An object is placed at 30 cm in front of the convex lens of focal length 10 cm. Find out the image distance from the lens?

On the basis of the four positions of a dice given below find the colour of the face opposite ‘Yellow’.

17.A monkey can jump a maximum horizontal distance of 2o m then find the velocity of monkey?

How much solar energy will be received by 125 meter square area on earth’s surface in eight hours if the solar constant is 1.4 kilowatt per square meter?

To an observer on Earth the stars appear to twinkle. This is due to

Which satellite is used specifically for managing the natural resources of the nation?

If all rays falling on a convex mirror are parallel to the principal axis of the mirror, what happens to them after reflection from the mirror?

The wires in a domestic circuit which are at the same potential are:

An observer stands at a distance of 850 m from the cliff and fires a gun. After what time will he hear the echo if sound travels at a speed of 350 ms−1 in air?

Name Age Year of becoming an astronaut No. of space Journeys Experience with zero gravity Ways of staying fit Memorable moments What one has learnt from the travels Peggy hitson

Handles of tools such as screwdrivers and pliers used by electricians for repair work usually have plastic or rubber cover on them. Can you explain why?

Match the following mirrors with their correct name i) Convex ii) Plane iii) Parabolic iv) Concave

what is wattless current and choke coil?

19 A solution of sucrose in 100g of water boils at 100.25C. If this solution is boiled till its temperature is 101C, the mass of water evaporated from the solution is A 25g B 50g C 75g D 85g

There is a straight wire carrying current as shown in the figure. What is the direction of the magnetic field around the wire when the reference point is above the wire?

What is the function of rods and cone cells?

the escape velocity from the earth is 11.2 km/s the mass of another planet is 100 times of mass of earth and its radius is 4 times the radius of earth.the escape velocity for the planet is

Two charged particles having charges q1 and q2 and masses m1 and m2 are projected with the same velocity in a region of uniform magnetic field. They follow the trajectory as shownIt can be concluded that

in a house individual power of two elements are 100w amd 150w effective power of their series will be

Define potential bareer in npn semiconductor

The values of current I flowing in a given resistor for the corresponding values of potential difference V across the resistor are given below − I (amperes ) 0.5 1.0 2.0 3.0 4.0 V (volts) 1.6 3.4 6.7 10.2 13.2 Plot a graph between V and I and calculate the resistance of that resistor.

Why does the eye need to change the focal length of the eye lens?

Why are environmentalists insisting upon 'sustainable natural resource management? Give any three reasons.

The repeated reflections that result in the persistence of sound is called___.

In an experiment to determine the emf E2 of an unknown cell, its emf is compared with a standard cell of known emf E1=1.12 V. The balance point is obtained at 56 cm with the standard cell and 80 cm with the unknown cell. Determine the emf of the unknown cell.

What is the principal of AC motor and DC motor

A radio isotope ′X′ with a half-life 1.4×109 years decays to ′Y′ which is stable. A sample of the rock from a cave was found to contain ′X′ and ′Y′ in the ratio 1:7. The age of the rock is

A telescope has an objective lens of focal length 200cm and an eye piece with focal length 2cm. If this telescope is used to see a 50m tall building at a distance of 2km, what is the height of the image of the building formed by the objective lens?

44. Why is electron gain enthalpy for alkali metals negative

a wire of resistivity is streched 3 times its original length. what would be its new resistivity?

If there is no gravitational force acting on an orbiting satellite,then why do we say that in an orbiting satellite,the required centripetal force is provided by the gravitational force and if this force vanishes then satellite would not be able to revolve in a circular motion?

Can 1 M NiSO4 be stored in a vessel made up of copper? E†extdegree_{Ni^{2+}/Ni}=-1.20 V and E†extdegree_{Cu^{2+}/Cu }= 0.34V.

ntIn a wave travelling along x-axis the displacement of particles is given by z=Asink(x-2) at t=1sec where x is in metre. Also displacement of particle is z=Asink(x+3) at t=2sec find the velocity of waven

In which direction does the wire move if the current flows through the wire in the downward direction?

Answer the following questions:(a) What is total internal reflection?(b) State two conditions necessary for the total internal reflection to occur.(c) Draw diagrams to illustrate the total internal reflection.

In a conductor if Q charges flow through it, in time t is the correct relation between electric current(I), charge and time.

Calculate the equivalent resistance of two resistors having resistances 3 Ω and 6 Ω connected in parallel.