16569 + Interview Questions in Physics

1.	34. A tube of length h(which is wide enough so that surface tension is neglected) filled with air and closed at one end is lowered in a tank of mercury to a depth h so that mercury rises a distance x into the tube. If the mercury barometer also reads h,then
Answer» 34. A tube of length h(which is wide enough so that surface tension is neglected) filled with air and closed at one end is lowered in a tank of mercury to a depth h so that mercury rises a distance x into the tube. If the mercury barometer also reads h,then

Discussion

2.	Is it possible for travelling at a speed more than the speed of light? Why
Answer» Is it possible for travelling at a speed more than the speed of light? Why

Discussion

3.	Images formed by totally reflected light are brighter than the images formed by ordinary reflected light. Why?
Answer» Images formed by totally reflected light are brighter than the images formed by ordinary reflected light. Why?

Discussion

4.	A block and tackle system has the its efficiency is 50% . The velocity ratio (VR) of the system is .
Answer» A block and tackle system has the its efficiency is 50% . The velocity ratio (VR) of the system is .

Discussion

5.	A charge particle enters a uniform magnetic field with velocity vector at angle of 45∘ with the magnetic field. The pitch of the helical path followed by the particle is P. The radius of the helix will be
Answer» A charge particle enters a uniform magnetic field with velocity vector at angle of $45^{\circ}$ with the magnetic field. The pitch of the helical path followed by the particle is $P$ . The radius of the helix will be

Discussion

6.	An object is placed at 15 cm from a convex lens of focal length 10cm.Where should be another convex mirror of radius 12cm placed such that image will coincide the object (a)18cm (b)17cm (c)14cm (d)20c
Answer» An object is placed at 15 cm from a convex lens of focal length 10cm.Where should be another convex mirror of radius 12cm placed such that image will coincide the object (a)18cm (b)17cm (c)14cm (d)20c

Discussion

7.	For how much time should a force of 200 act on object having mass 5 kg so as to increase velocity from 50m/sec to 100m/sec
Answer» For how much time should a force of 200 act on object having mass 5 kg so as to increase velocity from 50m/sec to 100m/sec

Discussion

8.	The amount of energy released on complete combustion of 1250 g of coal, if its calorific value is 30kJ/g, is
Answer» The amount of energy released on complete combustion of $1250 g$ of coal, if its calorific value is $30 k J / g,$ is

Discussion

9.	difine full stability ?
Answer» difine full stability ?

Discussion

10.	After tracing the path of rays of light through a glass slab for three different angles of incidence, a student measured the corresponding values angle of refraction r and angle of emergence e and recorded them in the table given below : S.NO∠i∠r∠eI30∘20∘31∘II40∘25∘40∘III50∘31∘49∘
Answer» After tracing the path of rays of light through a glass slab for three different angles of incidence, a student measured the corresponding values angle of refraction r and angle of emergence e and recorded them in the table given below : $\begin{matrix} S . N O & ∠ i & ∠ r & ∠ e I & 30^{\circ} & 20^{\circ} & 31^{\circ} I I & 40^{\circ} & 25^{\circ} & 40^{\circ} I I I & 50^{\circ} & 31^{\circ} & 49^{\circ} \end{matrix}$

Discussion

11.	What is the significance of building a dam in hydro power plants?
Answer» What is the significance of building a dam in hydro power plants?

Discussion

12.	Two point charges 5mC and 3mC are at position ( 1 3 2) and (3 5 1) resp find the forces F12 and F21 using vector form of couloumbs law.
Answer» Two point charges 5mC and 3mC are at position ( 1 3 2) and (3 5 1) resp find the forces F12 and F21 using vector form of couloumbs law.

Discussion

13.	(a) Give two examples of substances which are good conductors of electricity. Why do you think they are good conductors of electricity? (b) Calculate the resistance of a copper wire 1.0 km long and 0.50 mm diameter if the resistivity of copper is 1.7×10−8Ωm.
Answer» (a) Give two examples of substances which are good conductors of electricity. Why do you think they are good conductors of electricity? (b) Calculate the resistance of a copper wire 1.0 km long and 0.50 mm diameter if the resistivity of copper is $1.7 \times 10^{- 8} Ω m .$

Discussion

14.	Mention three properties of infrared radiations similar to the visible light.
Answer» Mention three properties of infrared radiations similar to the visible light.

Discussion

15.	Safety fuse is a device which protect the appliances in the circuite from the damages due to the flow ofexcess current. What is the principle of safety fuse
Answer» Safety fuse is a device which protect the appliances in the circuite from the damages due to the flow ofexcess current. What is the principle of safety fuse

Discussion

16.	At the interface of two transparent mediums, at the point of incidence, the incident ray, the refracted ray and the normal, all lie in_____.
Answer» At the interface of two transparent mediums, at the point of incidence, the incident ray, the refracted ray and the normal, all lie in_____.

Discussion

17.	86.A circular loop of radius r moves with a constant velocity v in a region with uniform magnetic field B. Calculate the potential difference between two points (A, B), (C, D) and (E, F) located on the loop.
Answer» 86.A circular loop of radius r moves with a constant velocity v in a region with uniform magnetic field B. Calculate the potential difference between two points (A, B), (C, D) and (E, F) located on the loop.

Discussion

18.	A car headlight bulb working on a 12 V car battery draws a current of 0.5 A. The resistance of the light bulb is: (a) 0.5Ω (b) 6Ω (c) 12Ω (d) 24Ω
Answer» A car headlight bulb working on a 12 V car battery draws a current of 0.5 A. The resistance of the light bulb is: (a) $0.5 Ω$ (b) $6 Ω$ (c) $12 Ω$ (d) $24 Ω$

Discussion

19.	What exactly are 1.quartz and 2.rock salt prisms ? Which range of wavelengths of the electromagnetic spectrum pass through each one of them?
Answer» What exactly are 1.quartz and 2.rock salt prisms ? Which range of wavelengths of the electromagnetic spectrum pass through each one of them?

Discussion

20.	At the time of short circuit, the current in the rest of the circuit ______ substantially.
Answer» At the time of short circuit, the current in the rest of the circuit ______ substantially.

Discussion

21.	Principle and working of electric motor
Answer» Principle and working of electric motor

Discussion

22.	The wire which is negative and has a black insulation cover is called as
Answer» The wire which is negative and has a black insulation cover is called as

Discussion

23.	In a rocket, fuel burns at the rate of 1 kg/s. Thisfuel is ejected from the rocket with a velocity of60 km/s.his exerts a force on the rocket equal to
Answer» In a rocket, fuel burns at the rate of 1 kg/s. Thisfuel is ejected from the rocket with a velocity of60 km/s.his exerts a force on the rocket equal to

Discussion

24.	What is hemiketal?
Answer» What is hemiketal?

Discussion

25.	A light ray from a medium having a refractive index 1.5 incident on another medium at an angle of 30 degrees. If the angle of refraction is 60 degrees, Find the refractive index of the second medium.
Answer» A light ray from a medium having a refractive index 1.5 incident on another medium at an angle of 30 degrees. If the angle of refraction is 60 degrees, Find the refractive index of the second medium.

Discussion

26.	The Brewster's angle ib for an interface dividing mediums of refractive index μ=1 and μ=√3 should be(Light is incident from rarer to denser medium)
Answer» The Brewster's angle $i_{b}$ for an interface dividing mediums of refractive index $μ = 1$ and $μ = \sqrt{3}$ should be $($ Light is incident from rarer to denser medium $)$

Discussion

27.	Optical fibres make use of which of the following?
Answer» Optical fibres make use of which of the following?

Discussion

28.	Which of the following was a recent major nuclear accident?
Answer» Which of the following was a recent major nuclear accident?

Discussion

29.	What is static electricity ?
Answer» What is static electricity ?

Discussion

30.	Among the following, which effect can be used sometimes to differentiate a true solution from a colloidal solution?
Answer» Among the following, which effect can be used sometimes to differentiate a true solution from a colloidal solution?

Discussion

31.	N lamps each of resistance r, are fed by a machine of resistance R. If light emitted by any lamp is proportional to the square of the heat produced, prove that the most efficient way of arranging them is to place them in parallel arcs, each containing n lamps , where n is the integer nearest to (NR/r)^{1/^{
Answer» N lamps each of resistance r, are fed by a machine of resistance R. If light emitted by any lamp is proportional to the square of the heat produced, prove that the most efficient way of arranging them is to place them in parallel arcs, each containing n lamps , where n is the integer nearest to (NR/r)^{1/^{

Discussion

32.	If the inner surface of a spherical mirror is reflecting it is called _____ mirror.
Answer» If the inner surface of a spherical mirror is reflecting it is called _____ mirror.

Discussion

33.	What is the branch of science that study the nature of photons?
Answer» What is the branch of science that study the nature of photons?

Discussion

34.	Q. 15 The image of a real object in a convex mirror is 4 cm from the mirror . if the mirror has a radius of curvature 24 cm , the magnification is
Answer» Q. 15 The image of a real object in a convex mirror is 4 cm from the mirror . if the mirror has a radius of curvature 24 cm , the magnification is

Discussion

35.	The mass defect in a nucleus is 3.5 amu. Then the binding energy of the nucleus is
Answer» The mass defect in a nucleus is $3.5 amu$ . Then the binding energy of the nucleus is

Discussion

36.	When a substance is converted from ___ , the heat evolved or absorbed is known as Heat of transition.
Answer» When a substance is converted from ___ , the heat evolved or absorbed is known as Heat of transition.

Discussion

37.	Identify the type of eye defect from the following pictures.
Answer» Identify the type of eye defect from the following pictures.

Discussion

38.	A conductor with a rectangular cross-section has dimensions (a×2a×4a) as shown in figure. Resistance across AB is x, across CD is y and across EF is z. Then
Answer» A conductor with a rectangular cross-section has dimensions $(a \times 2 a \times 4 a)$ as shown in figure. Resistance across AB is $x$ , across CD is $y$ and across EF is $z$ . Then

Discussion

39.	The sound produced by a thunderstorm is heard 10 s after the lightning is seen. Calculate the approximate distance of the thunder cloud. (Given speed of sound = 340 ms−1)
Answer» The sound produced by a thunderstorm is heard $10 s$ after the lightning is seen. Calculate the approximate distance of the thunder cloud. (Given speed of sound = $340 m s^{- 1}$ )

Discussion

40.	ntA plano-convex lens is silvered on its plane side and then it acts like a concave mirror of focal lenght 20cm, when the convex side is silvered it acts like a concave mirror of focal lenght 7 cm. The refractive index of the lens is __________.n
Answer» ntA plano-convex lens is silvered on its plane side and then it acts like a concave mirror of focal lenght 20cm, when the convex side is silvered it acts like a concave mirror of focal lenght 7 cm. The refractive index of the lens is __________.n

Discussion

41.	Give two points of difference between a step-up and a step-down transformer.
Answer» Give two points of difference between a step-up and a step-down transformer.

Discussion

42.	A rado wave's electric field is given by the expression {\overrightarrow E=E\operatorname{sin(kz-ω t)×(^\i+^\jmath)\cdot(a) Find the peak electric field. (b) Give a unit vector in the direction of the magnetic field at a { place and time where \operatorname{sin(kz-ω t) is positive.
Answer» A rado wave's electric field is given by the expression {\overrightarrow E=E\operatorname{sin(kz-ω t)×(^\i+^\jmath)\cdot(a) Find the peak electric field. (b) Give a unit vector in the direction of the magnetic field at a { place and time where \operatorname{sin(kz-ω t) is positive.

Discussion

43.	Four resistors of resistances 0.5Ω,1.5Ω,4Ω and 6Ω are connected in series to a battery of EMF 6V and negligible internal resistance. Calculate the: (a) current drawn from the cell. (b) potential difference at the end of each resistor. [4 MARKS]
Answer» Four resistors of resistances $0.5 Ω, 1.5 Ω, 4 Ω$ and $6 Ω$ are connected in series to a battery of EMF $6 V$ and negligible internal resistance. Calculate the: (a) current drawn from the cell. (b) potential difference at the end of each resistor. [4 MARKS]

Discussion

44.	A convex lens (n=2) is submerged in water that was previously suspended in the air. What would be the change in the focal length?
Answer» A convex lens (n=2) is submerged in water that was previously suspended in the air. What would be the change in the focal length?

Discussion

45.	An electric lamp of 100 Ω, a toaster of resistance 50 Ω, and a water filter of resistance 500 Ω are connected in parallel to a 220 V source. What is the resistance of an electric iron connected to the same source that takes as much current as all three appliances, and what is the current through it?
Answer» An electric lamp of 100 Ω, a toaster of resistance 50 Ω, and a water filter of resistance 500 Ω are connected in parallel to a 220 V source. What is the resistance of an electric iron connected to the same source that takes as much current as all three appliances, and what is the current through it?

Discussion

46.	What is the maximum power in kilowatts of the appliance that can be connected safely to a 13 A ; 230 V mains socket ?
Answer» What is the maximum power in kilowatts of the appliance that can be connected safely to a 13 A ; 230 V mains socket ?

Discussion

47.	ntFormula of wave velocityn
Answer» ntFormula of wave velocityn

Discussion

48.	The refractive index of diamond in much greater than that of ordinary glass. Is this fact of some use to a diamond-cutter?
Answer» The refractive index of diamond in much greater than that of ordinary glass. Is this fact of some use to a diamond-cutter?

Discussion

49.	Micro-organism responsible for decomposition during bio gas preparation are:
Answer» Micro-organism responsible for decomposition during bio gas preparation are:

Discussion

50.	4. Heat of formation of SO, is-298 kJ/mol what is heat ofcombustion of 4g of S?(1) +37(2)-37.25 kJ (3)298 kJ(4) 18.6 kJ
Answer» 4. Heat of formation of SO, is-298 kJ/mol what is heat ofcombustion of 4g of S?(1) +37(2)-37.25 kJ (3)298 kJ(4) 18.6 kJ

Discussion

Explore topic-wise InterviewSolutions in Current Affairs.

34. A tube of length h(which is wide enough so that surface tension is neglected) filled with air and closed at one end is lowered in a tank of mercury to a depth h so that mercury rises a distance x into the tube. If the mercury barometer also reads h,then

Is it possible for travelling at a speed more than the speed of light? Why

Images formed by totally reflected light are brighter than the images formed by ordinary reflected light. Why?

A block and tackle system has the its efficiency is 50% . The velocity ratio (VR) of the system is .

A charge particle enters a uniform magnetic field with velocity vector at angle of 45∘ with the magnetic field. The pitch of the helical path followed by the particle is P. The radius of the helix will be

An object is placed at 15 cm from a convex lens of focal length 10cm.Where should be another convex mirror of radius 12cm placed such that image will coincide the object (a)18cm (b)17cm (c)14cm (d)20c

For how much time should a force of 200 act on object having mass 5 kg so as to increase velocity from 50m/sec to 100m/sec

The amount of energy released on complete combustion of 1250 g of coal, if its calorific value is 30kJ/g, is

difine full stability ?

What is the significance of building a dam in hydro power plants?

Two point charges 5mC and 3mC are at position ( 1 3 2) and (3 5 1) resp find the forces F12 and F21 using vector form of couloumbs law.

(a) Give two examples of substances which are good conductors of electricity. Why do you think they are good conductors of electricity? (b) Calculate the resistance of a copper wire 1.0 km long and 0.50 mm diameter if the resistivity of copper is 1.7×10−8Ωm.

Mention three properties of infrared radiations similar to the visible light.

Safety fuse is a device which protect the appliances in the circuite from the damages due to the flow ofexcess current. What is the principle of safety fuse

At the interface of two transparent mediums, at the point of incidence, the incident ray, the refracted ray and the normal, all lie in_____.

86.A circular loop of radius r moves with a constant velocity v in a region with uniform magnetic field B. Calculate the potential difference between two points (A, B), (C, D) and (E, F) located on the loop.

A car headlight bulb working on a 12 V car battery draws a current of 0.5 A. The resistance of the light bulb is: (a) 0.5Ω (b) 6Ω (c) 12Ω (d) 24Ω

What exactly are 1.quartz and 2.rock salt prisms ? Which range of wavelengths of the electromagnetic spectrum ​pass through each one of them?

At the time of short circuit, the current in the rest of the circuit ______ substantially.

Principle and working of electric motor

The wire which is negative and has a black insulation cover is called as

In a rocket, fuel burns at the rate of 1 kg/s. Thisfuel is ejected from the rocket with a velocity of60 km/s.his exerts a force on the rocket equal to

What is hemiketal?

A light ray from a medium having a refractive index 1.5 incident on another medium at an angle of 30 degrees. If the angle of refraction is 60 degrees, Find the refractive index of the second medium.

The Brewster's angle ib for an interface dividing mediums of refractive index μ=1 and μ=√3 should be(Light is incident from rarer to denser medium)

Optical fibres make use of which of the following?

Which of the following was a recent major nuclear accident?

What is static electricity ?

Among the following, which effect can be used sometimes to differentiate a true solution from a colloidal solution?

If the inner surface of a spherical mirror is reflecting it is called _____ mirror.

What is the branch of science that study the nature of photons?

Q. 15 The image of a real object in a convex mirror is 4 cm from the mirror . if the mirror has a radius of curvature 24 cm , the magnification is

The mass defect in a nucleus is 3.5 amu. Then the binding energy of the nucleus is

When a substance is converted from ___ , the heat evolved or absorbed is known as Heat of transition.

Identify the type of eye defect from the following pictures.

A conductor with a rectangular cross-section has dimensions (a×2a×4a) as shown in figure. Resistance across AB is x, across CD is y and across EF is z. Then

The sound produced by a thunderstorm is heard 10 s after the lightning is seen. Calculate the approximate distance of the thunder cloud. (Given speed of sound = 340 ms−1)

ntA plano-convex lens is silvered on its plane side and then it acts like a concave mirror of focal lenght 20cm, when the convex side is silvered it acts like a concave mirror of focal lenght 7 cm. The refractive index of the lens is __________.n

Give two points of difference between a step-up and a step-down transformer.

A rado wave's electric field is given by the expression {\overrightarrow E=E\operatorname{sin(kz-ω t)×(^\i+^\jmath)\cdot(a) Find the peak electric field. (b) Give a unit vector in the direction of the magnetic field at a { place and time where \operatorname{sin(kz-ω t) is positive.

Four resistors of resistances 0.5Ω,1.5Ω,4Ω and 6Ω are connected in series to a battery of EMF 6V and negligible internal resistance. Calculate the: (a) current drawn from the cell. (b) potential difference at the end of each resistor. [4 MARKS]

A convex lens (n=2) is submerged in water that was previously suspended in the air. What would be the change in the focal length?

What is the maximum power in kilowatts of the appliance that can be connected safely to a 13 A ; 230 V mains socket ?

ntFormula of wave velocityn

The refractive index of diamond in much greater than that of ordinary glass. Is this fact of some use to a diamond-cutter?

Micro-organism responsible for decomposition during bio gas preparation are:

4. Heat of formation of SO, is-298 kJ/mol what is heat ofcombustion of 4g of S?(1) +37(2)-37.25 kJ (3)298 kJ(4) 18.6 kJ

What exactly are 1.quartz and 2.rock salt prisms ? Which range of wavelengths of the electromagnetic spectrum pass through each one of them?