50278 + Interview Questions in Physics

1.	A set of n equal resistors of value R each are connected in series to a battery of emf E and internal resistance R. The current drawn is I. Now, the n resistors are connected in parallel to the same battery. Then the current drawn from battery becomes 10 I. The value of n is
Answer» A set of $n$ equal resistors of value $R$ each are connected in series to a battery of emf $E$ and internal resistance $R$ . The current drawn is $I$ . Now, the $n$ resistors are connected in parallel to the same battery. Then the current drawn from battery becomes $10 I$ . The value of $n$ is

Discussion

2.	The speed of a freely falling body from rest is proportional to gphq, where g is acceleration due to gravity and h is the distance travelled. The values of p and q are
Answer» The speed of a freely falling body from rest is proportional to $g^{p} h^{q}$ , where $g$ is acceleration due to gravity and $h$ is the distance travelled. The values of $p$ and $q$ are

Discussion

3.	Consider a block of conducting material of resistivity ρ shown in the figure. Current l enters A and B leaves from D. We apply superposition principle to find voltage ΔV developed between B and C. The calculation is done in the following steps: (a) Take current l entering from A and assume it to spread over a hemispherical surface in the block. (b) Calculate field E(r) at distance r from A by using Ohm’s law E=ρj, where j is the current per unit area at r. (c) From the r dependence of E(r), obtain the potential V(r) at r. (d) Repeat (i), (ii) and (iii) for current l leaving D superpose results for A to D. ΔV measured between B and C is
Answer» Consider a block of conducting material of resistivity $ρ$ shown in the figure. Current l enters A and B leaves from D. We apply superposition principle to find voltage $Δ V$ developed between B and C. The calculation is done in the following steps: (a) Take current l entering from A and assume it to spread over a hemispherical surface in the block. (b) Calculate field E(r) at distance r from A by using Ohm’s law $E = ρ j$ , where j is the current per unit area at r. (c) From the r dependence of E(r), obtain the potential V(r) at r. (d) Repeat (i), (ii) and (iii) for current l leaving D superpose results for A to D. $Δ V$ measured between B and C is

3.

Consider a block of conducting material of resistivity ρ shown in the figure. Current l enters A and B leaves from D. We apply superposition principle to find voltage ΔV developed between B and C. The calculation is done in the following steps: (a) Take current l entering from A and assume it to spread over a hemispherical surface in the block. (b) Calculate field E(r) at distance r from A by using Ohm’s law E=ρj, where j is the current per unit area at r. (c) From the r dependence of E(r), obtain the potential V(r) at r. (d) Repeat (i), (ii) and (iii) for current l leaving D superpose results for A to D. ΔV measured between B and C is

Answer»

Consider a block of conducting material of resistivity $ρ$ shown in the figure. Current l enters A and B leaves from D. We apply superposition principle to find voltage $Δ V$ developed between B and C. The calculation is done in the following steps:
(a) Take current l entering from A and assume it to spread over a hemispherical surface in the block.
(b) Calculate field E(r) at distance r from A by using Ohm’s law $E = ρ j$ , where j is the current per unit area at r.
(c) From the r dependence of E(r), obtain the potential V(r) at r.
(d) Repeat (i), (ii) and (iii) for current l leaving D superpose results for A to D.

$Δ V$ measured between B and C is

Discussion

4.	Find the maximum force F to be applied for the system shown, so that the two blocks move together. Take g=10 m/s2.
Answer» Find the maximum force $F$ to be applied for the system shown, so that the two blocks move together. Take $g = 10 {m/s}^{2}$ .

Discussion

5.	A piece of gold weight 10.5185 g in air and 9.9735 g when immersed in water. What is the relative density of the gold?
Answer» A piece of gold weight 10.5185 g in air and 9.9735 g when immersed in water. What is the relative density of the gold?

Discussion

6.	The frequency (n) of vibration of a string is given as n=12l√Tm, where T is tension and l is the length of vibrating string. Then, the magnitude of summation of powers of M and L in the dimensional formula of m is
Answer» The frequency $(n)$ of vibration of a string is given as $n = \frac{1}{2 l} \sqrt{\frac{T}{m}}$ , where $T$ is tension and $l$ is the length of vibrating string. Then, the magnitude of summation of powers of $M$ and $L$ in the dimensional formula of $m$ is

Discussion

7.	Is it possible that a convergent lens in one medium becomes divergent when placed in another medium?
Answer» Is it possible that a convergent lens in one medium becomes divergent when placed in another medium?

Discussion

8.	A block of mass m placed on a smooth floor is connected to a fixed support with the help of a spring of stiffness k. It is pulled by a rope as shown in the figure. Tension force T of the rope is increased gradually without changing its direction until the block losses contact from the floor. The increase in rope tension T is so gradual that acceleration in the block can be neglected. What is the extension in the spring, when the block losses contact from the floor?
Answer» A block of mass $m$ placed on a smooth floor is connected to a fixed support with the help of a spring of stiffness $k$ . It is pulled by a rope as shown in the figure. Tension force $T$ of the rope is increased gradually without changing its direction until the block losses contact from the floor. The increase in rope tension $T$ is so gradual that acceleration in the block can be neglected. What is the extension in the spring, when the block losses contact from the floor?

Discussion

9.	Four homogeneous brick, each of length L=4 m, are arranged as shown in the figure. Each brick is displaced with respect to one in contact by L8. Find the x− coordinate of centre of mass relative to origin O.
Answer» Four homogeneous brick, each of length $L = 4 m$ , are arranged as shown in the figure. Each brick is displaced with respect to one in contact by $\frac{L}{8} .$ Find the $x -$ coordinate of centre of mass relative to origin $O$ .

Discussion

10.	∫(1x−ex−13)dx is equal to
Answer» $\int (\frac{1}{x} - e^{x} - \frac{1}{3}) d x$ is equal to

Discussion

11.	A target element A is bombarded with electrons and the wavelengths of the characteristic spectrum are measured. A second characteristic spectrum is also obtained because of an impurity in the target. The wavelength of the Kα lines are 196 pm (element A) and 169 pm (impurity). If the atomic number of impurity is z=(10x−1). Find the value of x. (atomic number of element A is 27).
Answer» A target element $A$ is bombarded with electrons and the wavelengths of the characteristic spectrum are measured. A second characteristic spectrum is also obtained because of an impurity in the target. The wavelength of the $K_{α}$ lines are $196 pm$ (element $A$ ) and $169 pm$ (impurity). If the atomic number of impurity is $z = (10 x - 1)$ . Find the value of $x$ . (atomic number of element $A$ is 27).

Discussion

12.	Acceleration of the particle in a rectilinear motion is given as a=2t−6 in (m/s2). The displacement as a function of time t respectively is (Given, at t=0,u=2 m/s,x=2 m)
Answer» Acceleration of the particle in a rectilinear motion is given as $a = 2 t - 6$ in $(m / s^{2})$ . The displacement as a function of time $t$ respectively is (Given, at $t = 0, u = 2 m / s, x = 2 m$ )

Discussion

13.	A stream of photons having energy 5 eV each impinges on a potassium surface. The work function of potassium is 3.0 eV. The emerging photo - electrons are slowed down by a copper plate placed 5 mm away. If the potential difference between the two metal plates is 1 V, the maximum distance (in mm) the electrons can move away from the potassium surface before being turned back is
Answer» A stream of photons having energy $5 e V$ each impinges on a potassium surface. The work function of potassium is $3.0 e V$ . The emerging photo - electrons are slowed down by a copper plate placed $5 m m$ away. If the potential difference between the two metal plates is $1 V$ , the maximum distance (in mm) the electrons can move away from the potassium surface before being turned back is

Discussion

14.	A gaseous mixture enclosed in a vessel of volume 2 m3 consists of 2 gm mole of a gas A with γA=CPCV=53, another gas B with γB=75 at a temperature 43∘C. The gram molecular weights of A & B are 32 and 4 respectively. Assume gas to be non - reacting & immiscible to each other . The gaseous mixture follows PV=2014=constant in adiabatic process. Find the number of gram moles of the gas B in the gaseous mixture.
Answer» A gaseous mixture enclosed in a vessel of volume $2 m^{3}$ consists of $2 gm$ mole of a gas A with $γ_{A} = \frac{C_{P}}{C_{V}} = \frac{5}{3}$ , another gas B with $γ_{B} = \frac{7}{5}$ at a temperature $43^{\circ} C$ . The gram molecular weights of A & B are $32$ and $4$ respectively. Assume gas to be non - reacting & immiscible to each other . The gaseous mixture follows $P V = \frac{20}{14} = constant$ in adiabatic process. Find the number of gram moles of the gas B in the gaseous mixture.

Discussion

15.	A ship A is moving eastwards with a speed of 20 km/h and a ship B ,50 km south of A is moving northwards with a speed of 20 km/h. Then find the shortest distance between the ships.
Answer» A ship $A$ is moving eastwards with a speed of $20 km/h$ and a ship $B$ , $50 km$ south of $A$ is moving northwards with a speed of $20 km/h$ . Then find the shortest distance between the ships.

Discussion

16.	If n identical water droplets falling under gravity with terminal velocity v coalesce to form a single drop which has the terminal velocity 4v. Find the number n.
Answer» If n identical water droplets falling under gravity with terminal velocity v coalesce to form a single drop which has the terminal velocity 4v. Find the number n.

Discussion

17.	A near ultraviolet Photon of wavelength 300 nm is observed by a gas and then remitted as 2 photons.One Photon is red, wavelength of which is 760 nm. What would be the wavelength of second Photon in manometer?
Answer» A near ultraviolet Photon of wavelength 300 nm is observed by a gas and then remitted as 2 photons.One Photon is red, wavelength of which is 760 nm. What would be the wavelength of second Photon in manometer?

Discussion

18.	After a perfectly inelastic collision between two identical balls moving with the same speed in different directions, the speed of the combined mass becomes half of their initial speed. The angle between the velocities of the two balls just before collision is
Answer» After a perfectly inelastic collision between two identical balls moving with the same speed in different directions, the speed of the combined mass becomes half of their initial speed. The angle between the velocities of the two balls just before collision is

Discussion

19.	An aeroplane of mass M requires a speed V for the take off . The length of the Runway is S and the coefficient of the friction between the tires and the ground is mew assuming that the plane accelerates uniformly during the take up the minimum force required by the engine of the plane for the takeoff is given by
Answer» An aeroplane of mass M requires a speed V for the take off . The length of the Runway is S and the coefficient of the friction between the tires and the ground is mew assuming that the plane accelerates uniformly during the take up the minimum force required by the engine of the plane for the takeoff is given by

Discussion

20.	A bird sees a fish swimming in a pond with a velocity of 5 m/s horizontally. If the fish is vertically below the bird initially, then in order to catch the fish, at what angle with the horizontal does the bird need to come, if the velocity of the bird is 10 m/s? (Assuming that there is no reflection of light)
Answer» A bird sees a fish swimming in a pond with a velocity of $5 m / s$ horizontally. If the fish is vertically below the bird initially, then in order to catch the fish, at what angle with the horizontal does the bird need to come, if the velocity of the bird is $10 m / s$ ? (Assuming that there is no reflection of light)

Discussion

21.	If the electric Field is given by 6i+3j+4k calculate the electric flux through a surface of area 20 units lying in Yz plane
Answer» If the electric Field is given by 6i+3j+4k calculate the electric flux through a surface of area 20 units lying in Yz plane

Discussion

22.	When the pressure is increased at a point , what would happen to the pressure at all other points if the liquid was not assumed to be incompressible?
Answer» When the pressure is increased at a point , what would happen to the pressure at all other points if the liquid was not assumed to be incompressible?

Discussion

23.	A cargo ship has the job of transporting goods from city A to city B on the downstream and come back upstream. If the velocity of ship in still water is 30 km/hr and velocity of the river stream is 15 km/hr. Find the average speed of the ship in the journey.
Answer» A cargo ship has the job of transporting goods from city A to city B on the downstream and come back upstream. If the velocity of ship in still water is 30 km/hr and velocity of the river stream is 15 km/hr. Find the average speed of the ship in the journey.

Discussion

24.	Prove that the relationship between the coefficients of linear,areal and volume expansion is 1:2:3
Answer» Prove that the relationship between the coefficients of linear,areal and volume expansion is 1:2:3

Discussion

25.	v^2=u^+2as when u=0 , v^2=2as but when we consider v=u+at , v=at since u=0 . wkt t=s/v which implies v=a(s/v) we get v^2=as how is this possible ?
Answer» v^2=u^+2as when u=0 , v^2=2as but when we consider v=u+at , v=at since u=0 . wkt t=s/v which implies v=a(s/v) we get v^2=as how is this possible ?

Discussion

26.	A stone is dropped into a river from a bridge 125 m above the water. Another stone is thrown vertically down 1.00s after the front is dropped. The stones strike the water at the same time. Which of these is the position time curve of the two stones as seen by a person who is standing directly below the point from where they are projected?
Answer» A stone is dropped into a river from a bridge 125 m above the water. Another stone is thrown vertically down 1.00s after the front is dropped. The stones strike the water at the same time. Which of these is the position time curve of the two stones as seen by a person who is standing directly below the point from where they are projected?

26.

A stone is dropped into a river from a bridge 125 m above the water. Another stone is thrown vertically down 1.00s after the front is dropped. The stones strike the water at the same time. Which of these is the position time curve of the two stones as seen by a person who is standing directly below the point from where they are projected?

Answer»

A stone is dropped into a river from a bridge 125 m above the water. Another stone is thrown vertically down 1.00s after the front is dropped. The stones strike the water at the same time.

Which of these is the position time curve of the two stones as seen by a person who is standing directly below the point from where they are projected?

Discussion

27.	A particle moving with a uniform acceleration travels 24 m and 64 m in the first two consecutive intervals of 4 sec each. Its initial velocity is
Answer» A particle moving with a uniform acceleration travels 24 m and 64 m in the first two consecutive intervals of 4 sec each. Its initial velocity is

Discussion

28.	A train travels from a city A to city B with a constant speed of 10 m/s and returns back to city A in half of the time taken to travel from A to B. Find its average speed during the entire journey.
Answer» A train travels from a city $A$ to city $B$ with a constant speed of $10 m/s$ and returns back to city $A$ in half of the time taken to travel from $A$ to $B$ . Find its average speed during the entire journey.

Discussion

29.	Moment of inertia of the system of two rods having same linear mass density λ, about the axis AB as shown in the figure is
Answer» Moment of inertia of the system of two rods having same linear mass density $λ$ , about the axis $A B$ as shown in the figure is

Discussion

30.	3 lenses L1, L2 and L3 each of focal length 30 cm are placed coaxially .an object is held at 60cm from the optical centre of lens L1.the final image is formed at the focus os L3.Calculate the separation between 1) L1 and L2 2) L2 and L3
Answer» 3 lenses L1, L2 and L3 each of focal length 30 cm are placed coaxially .an object is held at 60cm from the optical centre of lens L1.the final image is formed at the focus os L3.Calculate the separation between 1) L1 and L2 2) L2 and L3

Discussion

31.	The sunlight reaching the earth has maximum electric field of 810 V/m. What is the maximum magnetic field in this light?
Answer» The sunlight reaching the earth has maximum electric field of $810 V / m$ . What is the maximum magnetic field in this light?

Discussion

32.	Why tyres are filled with air ? Why not solids or liquids?
Answer» Why tyres are filled with air ? Why not solids or liquids?

Discussion

33.	The resistance of the rheostat shown in figure (32-E5) is 30 Ω. Neglecting the meter resistance, find the minimum and maximum currents through the ammeter as the rheostat is varied. figure (32-E5)
Answer» The resistance of the rheostat shown in figure (32-E5) is 30 $Ω$ . Neglecting the meter resistance, find the minimum and maximum currents through the ammeter as the rheostat is varied. figure (32-E5)

33.

The resistance of the rheostat shown in figure (32-E5) is 30 Ω. Neglecting the meter resistance, find the minimum and maximum currents through the ammeter as the rheostat is varied. figure (32-E5)

Answer»

The resistance of the rheostat shown in figure (32-E5) is 30 $Ω$ . Neglecting the meter resistance, find the minimum and maximum currents through the ammeter as the rheostat is varied.

figure (32-E5)

Discussion

34.	The root mean speed of gas molecules
Answer» The root mean speed of gas molecules

Discussion

35.	In figure (12-E3) k=100 N m−1, M=1 kg and F=10 N. (a) Fine the compression of the spring in the equilibrium position. (b) A sharp blow by some external agent imparts a speed of 2 m s−1 to the block towards left. Find the sum of the potential energy of the spring and the kinetic energy of the block at this instant. (c) Find the time period of the resulting simple harmonic motion. (d) Find the amplitude. (e) Write the potential energy of the spring when the block is at the left extreme. (f) Write the potential energy of the spring when the block is at the right extreme. The answers of (b), (e) and (f) are different. Explain why this does not violate the principle of conservation of energy.
Answer» In figure (12-E3) $k = 100 N m^{- 1}, M = 1 k g$ and $F = 10 N .$ (a) Fine the compression of the spring in the equilibrium position. (b) A sharp blow by some external agent imparts a speed of $2 m s^{- 1}$ to the block towards left. Find the sum of the potential energy of the spring and the kinetic energy of the block at this instant. (c) Find the time period of the resulting simple harmonic motion. (d) Find the amplitude. (e) Write the potential energy of the spring when the block is at the left extreme. (f) Write the potential energy of the spring when the block is at the right extreme. The answers of (b), (e) and (f) are different. Explain why this does not violate the principle of conservation of energy.

35.

In figure (12-E3) k=100 N m−1, M=1 kg and F=10 N. (a) Fine the compression of the spring in the equilibrium position. (b) A sharp blow by some external agent imparts a speed of 2 m s−1 to the block towards left. Find the sum of the potential energy of the spring and the kinetic energy of the block at this instant. (c) Find the time period of the resulting simple harmonic motion. (d) Find the amplitude. (e) Write the potential energy of the spring when the block is at the left extreme. (f) Write the potential energy of the spring when the block is at the right extreme. The answers of (b), (e) and (f) are different. Explain why this does not violate the principle of conservation of energy.

Answer»

In figure (12-E3) $k = 100 N m^{- 1}, M = 1 k g$ and $F = 10 N .$ (a) Fine the compression of the spring in the equilibrium position. (b) A sharp blow by some external agent imparts a speed of $2 m s^{- 1}$ to the block towards left. Find the sum of the potential energy of the spring and the kinetic energy of the block at this instant. (c) Find the time period of the resulting simple harmonic motion. (d) Find the amplitude. (e) Write the potential energy of the spring when the block is at the left extreme. (f) Write the potential energy of the spring when the block is at the right extreme.

The answers of (b), (e) and (f) are different. Explain why this does not violate the principle of conservation of energy.

Discussion

36.	A cricketer can throw a ball to a maximum horizontal distance of 100 m. The speed with which he throws the ball is (to the nearest integer)
Answer» A cricketer can throw a ball to a maximum horizontal distance of 100 m. The speed with which he throws the ball is (to the nearest integer)

Discussion

37.	Do metals conduct electricity?
Answer» Do metals conduct electricity?

Discussion

38.	A ball is hit by a batsman at an angle of 37∘ as shown in figure. With what minimum velocity should the man standing at P run so that he catches the ball just before it strikes the ground. Assume that height of man is negligible in comparison to maximum height of projectile. (Take g=10 m/s2)
Answer» A ball is hit by a batsman at an angle of $37^{\circ}$ as shown in figure. With what minimum velocity should the man standing at $P$ run so that he catches the ball just before it strikes the ground. Assume that height of man is negligible in comparison to maximum height of projectile. (Take $g = 10 {m/s}^{2}$ )

Discussion

39.	Two stones are dropped down simultaneously from different heights with initial speed u1=0 and u2=30 m/s respectively. If the initial distance between them is 10 m and mass of the first stone is twice that of the second stone, find the velocity of their COM after 2 s. [Take g=10 m/s2]
Answer» Two stones are dropped down simultaneously from different heights with initial speed $u_{1} = 0$ and $u_{2} = 30 m/s$ respectively. If the initial distance between them is $10 m$ and mass of the first stone is twice that of the second stone, find the velocity of their $C O M$ after $2 s$ . [Take $g = 10 {m/s}^{2}$ ]

Discussion

40.	Three moles of an ideal gas are taken through a cyclic process ABCA as shown in T−V indicator diagram. The gas loses 2510 J of heat in the complete cycle. If TA=100 K and TB=200 K, the work done by the gas during the process BC is (line AB if extended passes through origin)
Answer» Three moles of an ideal gas are taken through a cyclic process $A B C A$ as shown in $T - V$ indicator diagram. The gas loses $2510 J$ of heat in the complete cycle. If $T_{A} = 100 K$ and $T_{B} = 200 K$ , the work done by the gas during the process $B C$ is (line AB if extended passes through origin)

Discussion

41.	If F1=10 N and F2=15 N as shown in the figure, the resultant R will be [Hint: cos65∘=0.423]
Answer» If $F_{1} = 10 N$ and $F_{2} = 15 N$ as shown in the figure, the resultant $R$ will be [Hint: $cos 65^{\circ} = 0.423$ ]

Discussion

42.	A boat takes t1 time while going downstream between two fixed points A and B, and takes t2 time while going upstream through the same distance. If river does not flow, then the time taken by the boat to cover the same distance is
Answer» A boat takes $t_{1}$ time while going downstream between two fixed points $A$ and $B$ , and takes $t_{2}$ time while going upstream through the same distance. If river does not flow, then the time taken by the boat to cover the same distance is

Discussion

43.	As the position of an object (u) reflected from a concave mirror is varied, the position of the image (v) also varies. By letting the u changes from 0 to the graph between v versus u will be
Answer» As the position of an object (u) reflected from a concave mirror is varied, the position of the image (v) also varies. By letting the u changes from 0 to the graph between v versus u will be

Discussion

44.	Two point white dots are 1 mm apart on a black paper. The are viewed by the eye of pupil diameter 3 mm. Approximately, the minimum distance(in mt at which these dots can be resolved by the eye is Take wavelength to be 500 nm
Answer» Two point white dots are $1 mm$ apart on a black paper. The are viewed by the eye of pupil diameter $3 mm$ . Approximately, the minimum distance(in $m t$ at which these dots can be resolved by the eye is Take wavelength to be $500 nm$

Discussion

45.	A train has arrived into a track which is a semicircle. At an instant when the engine is at the forward end of the semi circular part of the track while the last carriage is at the rear end, the driver blows a whistle of frequency 200 Hz. Velocity of sound is 340 m/sec. Then the apparent frequency as observed by a passenger in the middle of the train at the same instant is, (the speed of the train is 30 m/second)
Answer» A train has arrived into a track which is a semicircle. At an instant when the engine is at the forward end of the semi circular part of the track while the last carriage is at the rear end, the driver blows a whistle of frequency 200 Hz. Velocity of sound is 340 m/sec. Then the apparent frequency as observed by a passenger in the middle of the train at the same instant is, (the speed of the train is 30 m/second)

45.

A train has arrived into a track which is a semicircle. At an instant when the engine is at the forward end of the semi circular part of the track while the last carriage is at the rear end, the driver blows a whistle of frequency 200 Hz. Velocity of sound is 340 m/sec. Then the apparent frequency as observed by a passenger in the middle of the train at the same instant is, (the speed of the train is 30 m/second)

Answer»

A train has arrived into a track which is a semicircle. At an instant when the engine is at the forward end of the semi circular part of the track while the last carriage is at the rear end, the driver blows a whistle of frequency 200 Hz. Velocity of sound is 340 m/sec. Then the apparent frequency as observed by a passenger in the middle of the train at the same instant is, (the speed of the train is 30 m/second)

Discussion

46.	Pressure exerted by 1 mole of methane in 0.25 litre container at 300 K using Van der Waal's equations? Given a=2.25 atm - L2/mol2 b=0.05 L/mol
Answer» Pressure exerted by $1 mole$ of methane in $0.25 litre$ container at $300 K$ using Van der Waal's equations? Given $a = 2.25 {atm - L}^{2} / {mol}^{2}$ $b = 0.05 L/mol$

Discussion

47.	Electric field of a point charge extends up to r where 1/r is
Answer» Electric field of a point charge extends up to r where 1/r is

47.

Electric field of a point charge extends up to r where 1/r is

Answer»

Electric field of a point charge extends up to r where 1/r is

Discussion

48.	The root mean square speed of the molecules of a gas at absolute temperature T is proportional to
Answer» The root mean square speed of the molecules of a gas at absolute temperature T is proportional to

Discussion

49.	Two particles are projected from towers of different heights with velocities as shown in the figure. Find angle ′θ′; if the particles collide (Given particles collide after 1 second and particles are projected at the same instant)
Answer» Two particles are projected from towers of different heights with velocities as shown in the figure. Find angle $^{'} θ^{'}$ ; if the particles collide (Given particles collide after 1 second and particles are projected at the same instant)

Discussion

50.	Seven homogeneous bricks, each of length L, are arranged as shown in figure (9.E2). Each brick is displaced with respect to the one in contact by L10. Find the x-coordinate of the centre of mass relative to the origin shown.
Answer» Seven homogeneous bricks, each of length L, are arranged as shown in figure (9.E2). Each brick is displaced with respect to the one in contact by $\frac{L}{10}$ . Find the x-coordinate of the centre of mass relative to the origin shown.

Discussion

Explore topic-wise InterviewSolutions in Current Affairs.

A set of n equal resistors of value R each are connected in series to a battery of emf E and internal resistance R. The current drawn is I. Now, the n resistors are connected in parallel to the same battery. Then the current drawn from battery becomes 10 I. The value of n is

The speed of a freely falling body from rest is proportional to gphq, where g is acceleration due to gravity and h is the distance travelled. The values of p and q are

Find the maximum force F to be applied for the system shown, so that the two blocks move together. Take g=10 m/s2.

A piece of gold weight 10.5185 g in air and 9.9735 g when immersed in water. What is the relative density of the gold?

The frequency (n) of vibration of a string is given as n=12l√Tm, where T is tension and l is the length of vibrating string. Then, the magnitude of summation of powers of M and L in the dimensional formula of m is

Is it possible that a convergent lens in one medium becomes divergent when placed in another medium?

Four homogeneous brick, each of length L=4 m, are arranged as shown in the figure. Each brick is displaced with respect to one in contact by L8. Find the x− coordinate of centre of mass relative to origin O.

∫(1x−ex−13)dx is equal to

Acceleration of the particle in a rectilinear motion is given as a=2t−6 in (m/s2). The displacement as a function of time t respectively is (Given, at t=0,u=2 m/s,x=2 m)

A ship A is moving eastwards with a speed of 20 km/h and a ship B ,50 km south of A is moving northwards with a speed of 20 km/h. Then find the shortest distance between the ships.

If n identical water droplets falling under gravity with terminal velocity v coalesce to form a single drop which has the terminal velocity 4v. Find the number n.

A near ultraviolet Photon of wavelength 300 nm is observed by a gas and then remitted as 2 photons.One Photon is red, wavelength of which is 760 nm. What would be the wavelength of second Photon in manometer?

After a perfectly inelastic collision between two identical balls moving with the same speed in different directions, the speed of the combined mass becomes half of their initial speed. The angle between the velocities of the two balls just before collision is

If the electric Field is given by 6i+3j+4k calculate the electric flux through a surface of area 20 units lying in Yz plane

When the pressure is increased at a point , what would happen to the pressure at all other points if the liquid was not assumed to be incompressible?

A cargo ship has the job of transporting goods from city A to city B on the downstream and come back upstream. If the velocity of ship in still water is 30 km/hr and velocity of the river stream is 15 km/hr. Find the average speed of the ship in the journey.

Prove that the relationship between the coefficients of linear,areal and volume expansion is 1:2:3

v^2=u^+2as when u=0 , v^2=2as but when we consider v=u+at , v=at since u=0 . wkt t=s/v which implies v=a(s/v) we get v^2=as how is this possible ?

A particle moving with a uniform acceleration travels 24 m and 64 m in the first two consecutive intervals of 4 sec each. Its initial velocity is

A train travels from a city A to city B with a constant speed of 10 m/s and returns back to city A in half of the time taken to travel from A to B. Find its average speed during the entire journey.

Moment of inertia of the system of two rods having same linear mass density λ, about the axis AB as shown in the figure is

3 lenses L1, L2 and L3 each of focal length 30 cm are placed coaxially .an object is held at 60cm from the optical centre of lens L1.the final image is formed at the focus os L3.Calculate the separation between 1) L1 and L2 2) L2 and L3

The sunlight reaching the earth has maximum electric field of 810 V/m. What is the maximum magnetic field in this light?

Why tyres are filled with air ? Why not solids or liquids?

The resistance of the rheostat shown in figure (32-E5) is 30 Ω. Neglecting the meter resistance, find the minimum and maximum currents through the ammeter as the rheostat is varied. figure (32-E5)

The root mean speed of gas molecules

A cricketer can throw a ball to a maximum horizontal distance of 100 m. The speed with which he throws the ball is (to the nearest integer)

Do metals conduct electricity?

A ball is hit by a batsman at an angle of 37∘ as shown in figure. With what minimum velocity should the man standing at P run so that he catches the ball just before it strikes the ground. Assume that height of man is negligible in comparison to maximum height of projectile. (Take g=10 m/s2)

Two stones are dropped down simultaneously from different heights with initial speed u1=0 and u2=30 m/s respectively. If the initial distance between them is 10 m and mass of the first stone is twice that of the second stone, find the velocity of their COM after 2 s. [Take g=10 m/s2]

Three moles of an ideal gas are taken through a cyclic process ABCA as shown in T−V indicator diagram. The gas loses 2510 J of heat in the complete cycle. If TA=100 K and TB=200 K, the work done by the gas during the process BC is (line AB if extended passes through origin)

If F1=10 N and F2=15 N as shown in the figure, the resultant R will be [Hint: cos65∘=0.423]

A boat takes t1 time while going downstream between two fixed points A and B, and takes t2 time while going upstream through the same distance. If river does not flow, then the time taken by the boat to cover the same distance is

As the position of an object (u) reflected from a concave mirror is varied, the position of the image (v) also varies. By letting the u changes from 0 to the graph between v versus u will be

Two point white dots are 1 mm apart on a black paper. The are viewed by the eye of pupil diameter 3 mm. Approximately, the minimum distance(in mt at which these dots can be resolved by the eye is Take wavelength to be 500 nm

Pressure exerted by 1 mole of methane in 0.25 litre container at 300 K using Van der Waal's equations? Given a=2.25 atm - L2/mol2 b=0.05 L/mol

Electric field of a point charge extends up to r where 1/r is

The root mean square speed of the molecules of a gas at absolute temperature T is proportional to

Two particles are projected from towers of different heights with velocities as shown in the figure. Find angle ′θ′; if the particles collide (Given particles collide after 1 second and particles are projected at the same instant)

Seven homogeneous bricks, each of length L, are arranged as shown in figure (9.E2). Each brick is displaced with respect to the one in contact by L10. Find the x-coordinate of the centre of mass relative to the origin shown.