50278 + Interview Questions in Physics Page 1 InterviewSolution

1.	One end of a steel wire is fixed to the ceiling of a moving elevator. A load of 20 kg hangs from the other end. If the elevator is moving up with an acceleration 1 m/s2 and Area of cross- section of wire is 2 cm2 then find the longitudnal strain in the wire.[Take g=10 ms−2,Y=2×1011 Nm−2 ]
Answer» One end of a steel wire is fixed to the ceiling of a moving elevator. A load of $20 kg$ hangs from the other end. If the elevator is moving up with an acceleration $1 {m/s}^{2}$ and Area of cross- section of wire is $2 {cm}^{2}$ then find the longitudnal strain in the wire. [Take $g = 10 {ms}^{- 2}, Y = 2 \times 10^{11} {Nm}^{- 2}$ ]

Discussion

2.	Current i0 is being carried by an infinite wire passing through origin along the direction i^+ j^ + k^. Find magnetic field due to the wire at point (1m,0,0).
Answer» Current i0 is being carried by an infinite wire passing through origin along the direction i^+ j^ + k^. Find magnetic field due to the wire at point (1m,0,0).

Discussion

3.	areunit vectors along x-and y-axisrespectively. What is the magnitude and direction of thevectorsand?What are the components of a vectoralongthe directions of and?[You may use graphical method]
Answer» are unit vectors along x- and y-axis respectively. What is the magnitude and direction of the vectorsand? What are the components of a vectoralong the directions of and? [You may use graphical method]

Discussion

4.	A parallel-plate capacitor having plate area A and plate separation d is joined to a battery of emf E and internal resistance R at t=0. Consider a plane surface of area A/2, parallel to the plates and situated symmetrically between them. If the displacement current through this surface as a function of time is given as:id=EnRe−tdε0ARWhere, ε0 is the permittivity of free space.The value of n is :
Answer» A parallel-plate capacitor having plate area $A$ and plate separation $d$ is joined to a battery of emf $E$ and internal resistance $R$ at $t = 0$ . Consider a plane surface of area $A / 2$ , parallel to the plates and situated symmetrically between them. If the displacement current through this surface as a function of time is given as: $i_{d} = \frac{E}{n R} e^{- \frac{t d}{ε_{0} A R}}$ Where, $ε_{0}$ is the permittivity of free space. The value of $n$ is :

Discussion

5.	A horizontal curve with superelevation e = 0.05 (note, e=tanβ ) has a posted speed limit of 60 km/h. For this speed limit, only those vehicles with Y/X ratio(in figure) greater than 2 and travelling at speeds greater than 1.2 times the speed limit, will overturn. However, with recent increase in truck traffic the speed limit needs to be modified such that only those vehicles with Y/X ratio greater than 3 and travelling at more than 1.2 times the speed limit will overturn. What should be the new speed limit?(in km/hr round off to integer) (with respect to the figure, assume that the vehicle is travelling into the plane of the paper).50
Answer» A horizontal curve with superelevation e = 0.05 (note, $e = t a n β$ ) has a posted speed limit of 60 km/h. For this speed limit, only those vehicles with Y/X ratio(in figure) greater than 2 and travelling at speeds greater than 1.2 times the speed limit, will overturn. However, with recent increase in truck traffic the speed limit needs to be modified such that only those vehicles with Y/X ratio greater than 3 and travelling at more than 1.2 times the speed limit will overturn. What should be the new speed limit?(in km/hr round off to integer) (with respect to the figure, assume that the vehicle is travelling into the plane of the paper). 50

5.

A horizontal curve with superelevation e = 0.05 (note, e=tanβ ) has a posted speed limit of 60 km/h. For this speed limit, only those vehicles with Y/X ratio(in figure) greater than 2 and travelling at speeds greater than 1.2 times the speed limit, will overturn. However, with recent increase in truck traffic the speed limit needs to be modified such that only those vehicles with Y/X ratio greater than 3 and travelling at more than 1.2 times the speed limit will overturn. What should be the new speed limit?(in km/hr round off to integer) (with respect to the figure, assume that the vehicle is travelling into the plane of the paper).50

Answer»

A horizontal curve with superelevation e = 0.05 (note, $e = t a n β$ ) has a posted speed limit of 60 km/h. For this speed limit, only those vehicles with Y/X ratio(in figure) greater than 2 and travelling at speeds greater than 1.2 times the speed limit, will overturn. However, with recent increase in truck traffic the speed limit needs to be modified such that only those vehicles with Y/X ratio greater than 3 and travelling at more than 1.2 times the speed limit will overturn. What should be the new speed limit?(in km/hr round off to integer) (with respect to the figure, assume that the vehicle is travelling into the plane of the paper).

50

Discussion

6.	Anair-cored solenoid with length 30 cm, area of cross-section 25 cm2and number of turns 500, carries a current of 2.5 A. The current issuddenly switched off in a brief time of 10−3s. How much is the average back emf induced across the ends of theopen switch in the circuit? Ignore the variation in magnetic fieldnear the ends of the solenoid.
Answer» An air-cored solenoid with length 30 cm, area of cross-section 25 cm² and number of turns 500, carries a current of 2.5 A. The current is suddenly switched off in a brief time of 10⁻³ s. How much is the average back emf induced across the ends of the open switch in the circuit? Ignore the variation in magnetic field near the ends of the solenoid.

Discussion

7.	A block of mass 30.0 kg is being brought down by a chain. If the block acquires a speed of 40.0 cms in dropping down 2.00 m, find the work done by the chain during the process.
Answer» A block of mass 30.0 kg is being brought down by a chain. If the block acquires a speed of 40.0 $\frac{c m}{s}$ in dropping down 2.00 m, find the work done by the chain during the process.

Discussion

8.	The electric current in an X- ray tube (from the target to the filament) operating at 40 kV is 10 mA. Assume that on an average, 1% of the total kinetic energy of the electrons hitting the target are converted into X−rays. The total power (in W) emitted as X-rays is (Integer only)
Answer» The electric current in an $X$ - ray tube (from the target to the filament) operating at $40 kV$ is $10 mA$ . Assume that on an average, $1 %$ of the total kinetic energy of the electrons hitting the target are converted into $X - rays$ . The total power $(in W)$ emitted as $X$ -rays is (Integer only)

Discussion

9.	If y=4x2x3+3, then dydx=
Answer» If $y = \frac{4 x^{2}}{x^{3} + 3},$ then $\frac{d y}{d x} =$

Discussion

10.	Two metal spheres (radii r1,r2 with r1<r2) are very far apart but are connected by a thin wire. If their combined charge is Q, then what is their common Potential?
Answer» Two metal spheres (radii $r_{1}, r_{2}$ with $r_{1} < r_{2}$ ) are very far apart but are connected by a thin wire. If their combined charge is $Q$ , then what is their common Potential?

Discussion

11.	The velocity-displacement graph describing the motion of a bicycle is shown in the figure.The acceleration-displacement graph of the bicycle’s motion is best described by:
Answer» The velocity-displacement graph describing the motion of a bicycle is shown in the figure. The acceleration-displacement graph of the bicycle’s motion is best described by:

11.

The velocity-displacement graph describing the motion of a bicycle is shown in the figure.The acceleration-displacement graph of the bicycle’s motion is best described by:

Answer»

The velocity-displacement graph describing the motion of a bicycle is shown in the figure.

The acceleration-displacement graph of the bicycle’s motion is best described by:

Discussion

12.	The energy E of an oscillating body in simple harmonic motion depends on its mass M , freguency N and amplitude A . using the method of dimension analysis find the relation between E , M, N , and A
Answer» The energy E of an oscillating body in simple harmonic motion depends on its mass M , freguency N and amplitude A . using the method of dimension analysis find the relation between E , M, N , and A

Discussion

13.	In half-wave rectification, what is the output frequency if the input frequency is 50 Hz. What is the output frequency of a full-wave rectifier for the same input frequency.
Answer» In half-wave rectification, what is the output frequency if the input frequency is 50 Hz. What is the output frequency of a full-wave rectifier for the same input frequency.

Discussion

14.	How much energy is needed to move a body of 103 kg mass from Earth's surface to a height of 2RE?(RE=radius of Earth=6400 km)
Answer» How much energy is needed to move a body of $10^{3} k g$ mass from Earth's surface to a height of $2 R_{E}$ ? $(R_{E} = r a d i u s o f E a r t h = 6400 k m)$

Discussion

15.	In the circuit shown, the input waveform is given. Which of the following correctly gives the output waveform across RL?
Answer» In the circuit shown, the input waveform is given. Which of the following correctly gives the output waveform across RL?

Discussion

16.	The chain of length L is released from rest on a smooth fixed incline with x=0 as shown in the figure. Determine velocity v of the chain when a half of the length has fallen (Take L=425 m) in m/s. (Neglect edge effect of inclined).
Answer» The chain of length $L$ is released from rest on a smooth fixed incline with $x = 0$ as shown in the figure. Determine velocity $v$ of the chain when a half of the length has fallen (Take $L = \frac{4}{25} m)$ in $m / s$ . (Neglect edge effect of inclined).

Discussion

17.	A train is travelling at 120 kmph and blows a whistle of frequency 1000 Hz. The frequencies of the sound heard by a stationary observer, if the train is approaching him and moving away from him are:[(Velocity of sound in air =330 m/s and assume medium is stationary]
Answer» A train is travelling at $120 kmph$ and blows a whistle of frequency $1000 Hz$ . The frequencies of the sound heard by a stationary observer, if the train is approaching him and moving away from him are: [(Velocity of sound in air $= 330 m/s$ and assume medium is stationary]

Discussion

18.	Ubjective lype Questluns1.The branch of physics which deals with colour forceand the behaviour of quarks is called(1) Quantum electrodynamics(2)/ Quantum chromodynamics(3) Quantum electrostatics4)Quantum chromostaticsS
Answer» Ubjective lype Questluns1.The branch of physics which deals with colour forceand the behaviour of quarks is called(1) Quantum electrodynamics(2)/ Quantum chromodynamics(3) Quantum electrostatics4)Quantum chromostaticsS

Discussion

19.	The flat surface of a large cast iron part measuring 1.5m×0.6m×0.25m is to be machined on planer. The cutting speed is 21 m/min, return speed is 42 m /min, feed is 2 mm/ stroke, time for reversing the table is 0.02 min. Approach and over travel are 20 mm each, machining allowance on either side of plate width is 5.5 mm. The planning time will be _______ s. (Correct to-one decimal place) 2386.8
Answer» The flat surface of a large cast iron part measuring $1.5 m \times 0.6 m \times 0.25 m$ is to be machined on planer. The cutting speed is 21 m/min, return speed is 42 m /min, feed is 2 mm/ stroke, time for reversing the table is 0.02 min. Approach and over travel are 20 mm each, machining allowance on either side of plate width is 5.5 mm. The planning time will be _______ s. (Correct to-one decimal place) 2386.8

Discussion

20.	If in two cases a body is thrown from a height H with initial velocity 'u'. Where in first case body is thrown vertically up and reaches ground with final velocity 'v1' in time 't1' and in second case it is thrown vertically down and reaches ground with velocity 'v2' in time 't2'. Find expression for- 1)H 2)u 3)t
Answer» If in two cases a body is thrown from a height H with initial velocity 'u'. Where in first case body is thrown vertically up and reaches ground with final velocity 'v1' in time 't1' and in second case it is thrown vertically down and reaches ground with velocity 'v2' in time 't2'. Find expression for- 1)H 2)u 3)t

Discussion

21.	23. A small block is released from point A in the figure it slides on the smooth surface and lease contact with the surface at b horizontally the horizontal range of the block will be maximum when H/h=
Answer» 23. A small block is released from point A in the figure it slides on the smooth surface and lease contact with the surface at b horizontally the horizontal range of the block will be maximum when H/h=

Discussion

22.	If the angular momentum of a particle of mass m rotating along a circular path of radius r with uniform speed is L, the centripetal force acting on the particle is
Answer» If the angular momentum of a particle of mass $m$ rotating along a circular path of radius $r$ with uniform speed is $L$ , the centripetal force acting on the particle is

Discussion

23.	heat travels throught vaccum by
Answer» heat travels throught vaccum by

Discussion

24.	A series LCR circuithas R=5vohm,L=40mH and C=1μ F` the bandwidth of the circuit
Answer» A series LCR circuithas R=5vohm,L=40mH and C=1μ F` the bandwidth of the circuit

Discussion

25.	The prism shown in the figure has a refractive index of 1.60 and angle A as 30∘. Two parallel light rays P and Q enter the prism. The angle between the light rays, when they emerge is:[Given: sin−1(0.8)=53∘]
Answer» The prism shown in the figure has a refractive index of $1.60$ and angle $A$ as $30^{\circ}$ . Two parallel light rays $P$ and $Q$ enter the prism. The angle between the light rays, when they emerge is: $[$ Given: ${sin}^{- 1} (0.8) = 53^{\circ}]$

Discussion

26.	13.A stationary radioactive nucleus (A =238 ) emits an alpha partical with kinetic energy = 4.1 MeV.The speed of recoil of the nucleus will be a 440000 m/s b 340000 m/s c 240000 m/s d 540000 m/s
Answer» 13.A stationary radioactive nucleus (A =238 ) emits an alpha partical with kinetic energy = 4.1 MeV.The speed of recoil of the nucleus will be a 440000 m/s b 340000 m/s c 240000 m/s d 540000 m/s

Discussion

27.	32. A man of mass 50 kg is standing in an elevator. If elevator is moving up with an acceleration g/3 then work done by normal reaction of floor of elevator on man when elevator moves by a distance 12m is (g=10m/s²)____? A)2000j b)4000j c)6000j d)8000j
Answer» 32. A man of mass 50 kg is standing in an elevator. If elevator is moving up with an acceleration g/3 then work done by normal reaction of floor of elevator on man when elevator moves by a distance 12m is (g=10m/s²)____? A)2000j b)4000j c)6000j d)8000j

Discussion

28.	13.Find the number of different words that can be formed from the letters of theword “Triangle” so that no vowels are together.
Answer» 13.Find the number of different words that can be formed from the letters of the word “Triangle” so that no vowels are together.

Discussion

29.	Two particles A and B are located at coordinates (20,0)m and (30,0)m. Relative position of A w.r.t. B is
Answer» Two particles $A$ and $B$ are located at coordinates $(20, 0) m$ and $(30, 0) m$ . Relative position of $A$ w.r.t. $B$ is

Discussion

30.	With what angular velocity ω (in rad/s) should we rotate the disc so that a mass hanging on to the periphery by a thread of length l=3524m is deviated from the vertical by an angle α=37∘ in steady state (Fig).? Radius of the disc R=1 m.
Answer» With what angular velocity $ω$ (in rad/s) should we rotate the disc so that a mass hanging on to the periphery by a thread of length $l = \frac{35}{24} m$ is deviated from the vertical by an angle $α = 37^{\circ}$ in steady state (Fig).? Radius of the disc $R = 1 m$ .

Discussion

31.	A projectile is thrown so as to have a maximum possible horizontal range of 400 m. Taking the point of projection as the origin, the co-ordinates of the point where the velocity of the projectile is minimum is
Answer» A projectile is thrown so as to have a maximum possible horizontal range of $400 m$ . Taking the point of projection as the origin, the co-ordinates of the point where the velocity of the projectile is minimum is

Discussion

32.	a solid spherical ball is rolling without slipping down an inclined plane . The fraction of it's total energy associated with rotation
Answer» a solid spherical ball is rolling without slipping down an inclined plane . The fraction of it's total energy associated with rotation

Discussion

33.	Q. A disc of radius R rolls on a rough horizontal surface. The dis†an ce covered by the point A in one revolution is 2ππ R 2R 8R ππ R
Answer» Q. A disc of radius R rolls on a rough horizontal surface. The dis†an ce covered by the point A in one revolution is 2ππ R 2R 8R ππ R

Discussion

34.	In a region of space, there is an electric field of 103 NC−1 towards west. A body having deficient of 106 electrons is lying in this region. The magnitude and direction of force acting on the body will be
Answer» In a region of space, there is an electric field of $10^{3} {NC}^{- 1}$ towards west. A body having deficient of $10^{6}$ electrons is lying in this region. The magnitude and direction of force acting on the body will be

Discussion

35.	A very large number of particles of same mass m are kept in xy plane at points (1,1) , (2,2) , (4,4) , (8,8) and so on . The total gravitational feild at the origin has the magnitude
Answer» A very large number of particles of same mass m are kept in xy plane at points (1,1) , (2,2) , (4,4) , (8,8) and so on . The total gravitational feild at the origin has the magnitude

Discussion

36.	A force F is applied horizontally on mass m1 as shown in figure. Find the contact force between m1 and m2.
Answer» A force $F$ is applied horizontally on mass $m_{1}$ as shown in figure. Find the contact force between $m_{1}$ and $m_{2}$ .

Discussion

37.	Potentiometer wire AB has length = 100 cm. Total resistance of wire is 10 Ω, when the jockey is connected at D (AD=10xcm), ammeter reading is 0.5 amp. Value of x is. (Resistance of ammeter is 1Ω and the cell has no internal resistance) ___.
Answer» Potentiometer wire AB has length = 100 cm. Total resistance of wire is $10 Ω$ , when the jockey is connected at D $(A D = 10 x c m)$ , ammeter reading is 0.5 amp. Value of x is. (Resistance of ammeter is $1 Ω$ and the cell has no internal resistance) ___.

Discussion

38.	The 6563 Å Hα line emitted by hydrogen in a star is found to be red-shifted by 15 Å. Estimate the speed with which the star is receding from the Earth.
Answer» The 6563 Å Hα line emitted by hydrogen in a star is found to be red-shifted by 15 Å. Estimate the speed with which the star is receding from the Earth.

Discussion

39.	A short magnet makes 40 oscillations per minute when used in an oscillations magnetometer at a place where the earth's horizontal magnetic field is 25 μ T. Another short magnet of magnetic moment 1.6 A m2 is placed 20 cm east of the oscillation if the magnet has its north pole (a) towards north and (b) towards south.
Answer» A short magnet makes 40 oscillations per minute when used in an oscillations magnetometer at a place where the earth's horizontal magnetic field is 25 $μ T$ . Another short magnet of magnetic moment 1.6 A $m^{2}$ is placed 20 cm east of the oscillation if the magnet has its north pole (a) towards north and (b) towards south.

Discussion

40.	8.A magnet of moment M is approaching a circular conducting ring of radius r with a constant velocity v as shown. Length of the magnet is perpendicular to the plane of the ring and passing through its centre. A repulsive force acts between the ring and magnet which varies with distance r between them as Thanks,
Answer» 8.A magnet of moment M is approaching a circular conducting ring of radius r with a constant velocity v as shown. Length of the magnet is perpendicular to the plane of the ring and passing through its centre. A repulsive force acts between the ring and magnet which varies with distance r between them as Thanks,

Discussion

41.	Ten one-rupee coins are put on top of each other on a table. Each coin has a mass m. Give the magnitude and direction of (a) the force on the 7th coin (counted from the bottom) due to all the coins on its top, (b) the force on the 7th coin by the eighth coin, (c) the reaction of the 6th coin on the 7th coin.
Answer» Ten one-rupee coins are put on top of each other on a table. Each coin has a mass m. Give the magnitude and direction of (a) the force on the 7th coin (counted from the bottom) due to all the coins on its top, (b) the force on the 7th coin by the eighth coin, (c) the reaction of the 6th coin on the 7th coin.

Discussion

42.	A particle of mass m moves on a straight line withits velocity varying with the distance travelled. If therelation between velocity and distance is v Kx (Kis constant), then find the work done by the forcesduring a displacement x 0 to x = d.VERYmkd2(1)2mk2d2(2)2mdok34)2mk^° d23)2
Answer» A particle of mass m moves on a straight line withits velocity varying with the distance travelled. If therelation between velocity and distance is v Kx (Kis constant), then find the work done by the forcesduring a displacement x 0 to x = d.VERYmkd2(1)2mk2d2(2)2mdok34)2mk^° d23)2

Discussion

43.	What is difference between electron gain enthalpy and electron affinity ?
Answer» What is difference between electron gain enthalpy and electron affinity ?

Discussion

44.	The ratio of wavelength of 1st line of balmer series and that of second line of Lyman series, in hydrogen spectrum is
Answer» The ratio of wavelength of 1st line of balmer series and that of second line of Lyman series, in hydrogen spectrum is

Discussion

45.	1. A stone is dropped from a balloon at an altitude of 300m. how long will the stone take to reach the ground if(a) the balloon is ascending with a velocity of 5m/s (b) the balloon id descending with a velocity of 5m/s (c) the balloon is stationary?
Answer» 1. A stone is dropped from a balloon at an altitude of 300m. how long will the stone take to reach the ground if(a) the balloon is ascending with a velocity of 5m/s (b) the balloon id descending with a velocity of 5m/s (c) the balloon is stationary?

Discussion

46.	The Sea is BigThe sea is big.It is very, very big.You cannot see the other side of the sea.You can cross the sea in a shipBut you must go for many, many days.Choose the right words.1. The sea is very, very ___________________ (big/far).2. You cannot ___________________ (hear/see) the other side.3. You ___________________ (can/cannot) cross the sea.4. You can cross it in a _________________ (bus/ship).
Answer» The Sea is Big The sea is big. It is very, very big. You cannot see the other side of the sea. You can cross the sea in a ship But you must go for many, many days. Choose the right words. 1. The sea is very, very ___________________ (big/far). 2. You cannot ___________________ (hear/see) the other side. 3. You ___________________ (can/cannot) cross the sea. 4. You can cross it in a _________________ (bus/ship).

Discussion

47.	A semicircular ring of radius R uniformly charged with chage Q is rotated with angular velocity ω about point P as shown in figure. Its magnetic dipole moment will be.
Answer» A semicircular ring of radius R uniformly charged with chage Q is rotated with angular velocity $ω$ about point P as shown in figure. Its magnetic dipole moment will be.

Discussion

48.	Define additivity?
Answer» Define additivity?

Discussion

49.	A shell in a flight explodes into 4 in parts Why can't potential energy and kinetic energy be conserved??Can they be constant??
Answer» A shell in a flight explodes into 4 in parts Why can't potential energy and kinetic energy be conserved?? Can they be constant??

Discussion

50.	The equivalent inductance of two inductances is 2.4 henry when connected in parallel and 10 henry when connected in series. The difference betweenthe two inductances is (1) 2 henry (2) 3 henry (3) 4 henry(4) 5 henry
Answer» The equivalent inductance of two inductances is 2.4 henry when connected in parallel and 10 henry when connected in series. The difference betweenthe two inductances is (1) 2 henry (2) 3 henry (3) 4 henry(4) 5 henry

Discussion

Explore topic-wise InterviewSolutions in .

One end of a steel wire is fixed to the ceiling of a moving elevator. A load of 20 kg hangs from the other end. If the elevator is moving up with an acceleration 1 m/s2 and Area of cross- section of wire is 2 cm2 then find the longitudnal strain in the wire.[Take g=10 ms−2,Y=2×1011 Nm−2 ]

Current i0 is being carried by an infinite wire passing through origin along the direction i^+ j^ + k^. Find magnetic field due to the wire at point (1m,0,0).

areunit vectors along x-and y-axisrespectively. What is the magnitude and direction of thevectorsand?What are the components of a vectoralongthe directions of and?[You may use graphical method]

A block of mass 30.0 kg is being brought down by a chain. If the block acquires a speed of 40.0 cms in dropping down 2.00 m, find the work done by the chain during the process.

The electric current in an X- ray tube (from the target to the filament) operating at 40 kV is 10 mA. Assume that on an average, 1% of the total kinetic energy of the electrons hitting the target are converted into X−rays. The total power (in W) emitted as X-rays is (Integer only)

If y=4x2x3+3, then dydx=

Two metal spheres (radii r1,r2 with r1&lt;r2) are very far apart but are connected by a thin wire. If their combined charge is Q, then what is their common Potential?

The velocity-displacement graph describing the motion of a bicycle is shown in the figure.The acceleration-displacement graph of the bicycle’s motion is best described by:

The energy E of an oscillating body in simple harmonic motion depends on its mass M , freguency N and amplitude A . using the method of dimension analysis find the relation between E , M, N , and A

In half-wave rectification, what is the output frequency if the input frequency is 50 Hz. What is the output frequency of a full-wave rectifier for the same input frequency.

How much energy is needed to move a body of 103 kg mass from Earth's surface to a height of 2RE?(RE=radius of Earth=6400 km)

In the circuit shown, the input waveform is given. Which of the following correctly gives the output waveform across RL?

The chain of length L is released from rest on a smooth fixed incline with x=0 as shown in the figure. Determine velocity v of the chain when a half of the length has fallen (Take L=425 m) in m/s. (Neglect edge effect of inclined).

A train is travelling at 120 kmph and blows a whistle of frequency 1000 Hz. The frequencies of the sound heard by a stationary observer, if the train is approaching him and moving away from him are:[(Velocity of sound in air =330 m/s and assume medium is stationary]

Ubjective lype Questluns1.The branch of physics which deals with colour forceand the behaviour of quarks is called(1) Quantum electrodynamics(2)/ Quantum chromodynamics(3) Quantum electrostatics4)Quantum chromostaticsS

23. A small block is released from point A in the figure it slides on the smooth surface and lease contact with the surface at b horizontally the horizontal range of the block will be maximum when H/h=

If the angular momentum of a particle of mass m rotating along a circular path of radius r with uniform speed is L, the centripetal force acting on the particle is

heat travels throught vaccum by

A series LCR circuithas R=5vohm,L=40mH and C=1μ F` the bandwidth of the circuit

The prism shown in the figure has a refractive index of 1.60 and angle A as 30∘. Two parallel light rays P and Q enter the prism. The angle between the light rays, when they emerge is:[Given: sin−1(0.8)=53∘]

13.A stationary radioactive nucleus (A =238 ) emits an alpha partical with kinetic energy = 4.1 MeV.The speed of recoil of the nucleus will be a 440000 m/s b 340000 m/s c 240000 m/s d 540000 m/s

32. A man of mass 50 kg is standing in an elevator. If elevator is moving up with an acceleration g/3 then work done by normal reaction of floor of elevator on man when elevator moves by a distance 12m is (g=10m/s²)____? A)2000j b)4000j c)6000j d)8000j

13.Find the number of different words that can be formed from the letters of theword “Triangle” so that no vowels are together.

Two particles A and B are located at coordinates (20,0)m and (30,0)m. Relative position of A w.r.t. B is

With what angular velocity ω (in rad/s) should we rotate the disc so that a mass hanging on to the periphery by a thread of length l=3524m is deviated from the vertical by an angle α=37∘ in steady state (Fig).? Radius of the disc R=1 m.

A projectile is thrown so as to have a maximum possible horizontal range of 400 m. Taking the point of projection as the origin, the co-ordinates of the point where the velocity of the projectile is minimum is

a solid spherical ball is rolling without slipping down an inclined plane . The fraction of it's total energy associated with rotation

Q. A disc of radius R rolls on a rough horizontal surface. The dis†an ce covered by the point A in one revolution is 2ππ R 2R 8R ππ R

In a region of space, there is an electric field of 103 NC−1 towards west. A body having deficient of 106 electrons is lying in this region. The magnitude and direction of force acting on the body will be

A very large number of particles of same mass m are kept in xy plane at points (1,1) , (2,2) , (4,4) , (8,8) and so on . The total gravitational feild at the origin has the magnitude

A force F is applied horizontally on mass m1 as shown in figure. Find the contact force between m1 and m2.

Potentiometer wire AB has length = 100 cm. Total resistance of wire is 10 Ω, when the jockey is connected at D (AD=10xcm), ammeter reading is 0.5 amp. Value of x is. (Resistance of ammeter is 1Ω and the cell has no internal resistance) ___.

The 6563 Å Hα line emitted by hydrogen in a star is found to be red-shifted by 15 Å. Estimate the speed with which the star is receding from the Earth.

A particle of mass m moves on a straight line withits velocity varying with the distance travelled. If therelation between velocity and distance is v Kx (Kis constant), then find the work done by the forcesduring a displacement x 0 to x = d.VERYmkd2(1)2mk2d2(2)2mdok34)2mk^° d23)2

What is difference between electron gain enthalpy and electron affinity ?

The ratio of wavelength of 1st line of balmer series and that of second line of Lyman series, in hydrogen spectrum is

1. A stone is dropped from a balloon at an altitude of 300m. how long will the stone take to reach the ground if(a) the balloon is ascending with a velocity of 5m/s (b) the balloon id descending with a velocity of 5m/s (c) the balloon is stationary?

A semicircular ring of radius R uniformly charged with chage Q is rotated with angular velocity ω about point P as shown in figure. Its magnetic dipole moment will be.

Define additivity?

A shell in a flight explodes into 4 in parts Why can't potential energy and kinetic energy be conserved??Can they be constant??

The equivalent inductance of two inductances is 2.4 henry when connected in parallel and 10 henry when connected in series. The difference betweenthe two inductances is (1) 2 henry (2) 3 henry (3) 4 henry(4) 5 henry

Two metal spheres (radii r1,r2 with r1<r2) are very far apart but are connected by a thin wire. If their combined charge is Q, then what is their common Potential?