50278 + Interview Questions in Physics

1.	The unit vector parallel to the resultant of the vectors →A=4^i+3^j+6^k and →B=−^i+3^j−8^k is
Answer» The unit vector parallel to the resultant of the vectors $\to A = 4^i + 3^j + 6^k$ and $\to B = -^i + 3^j - 8^k$ is

Discussion

2.	A capacitor with stored energy 4 J is connected with an identical capacitor with no electric field in between. Find the total energy stored in the two capacitors.
Answer» A capacitor with stored energy 4 J is connected with an identical capacitor with no electric field in between. Find the total energy stored in the two capacitors.

Discussion

3.	A uniform chain of mass M and length L is held on a horizontal frictionless table with 1nth of its length hanging over the edge of the table. The work done is pulling the chain up on the table is
Answer» A uniform chain of mass $M$ and length $L$ is held on a horizontal frictionless table with $\frac{1}{n^{t h}}$ of its length hanging over the edge of the table. The work done is pulling the chain up on the table is

Discussion

4.	A projectile thrown with a speed v at an angle θ has a range R on the surface of earth. For same v and θ, its range on the surface of moon will be
Answer» A projectile thrown with a speed v at an angle $θ$ has a range R on the surface of earth. For same v and $θ$ , its range on the surface of moon will be

Discussion

5.	A solid sphere of radius 20 cm is subjected to a uniform pressure of 106 Nm−2. If the bulk modulus of the solid is 1.7×1011 Nm−2, the decrease in the volume of the solid is approximately equal to
Answer» A solid sphere of radius 20 cm is subjected to a uniform pressure of $10^{6} N m^{- 2}$ . If the bulk modulus of the solid is $1.7 \times 10^{11} N m^{- 2}$ , the decrease in the volume of the solid is approximately equal to

Discussion

6.	In one cycle of the engine, the net change in the entropy of both reservoirs (hot and cold together) is:
Answer» In one cycle of the engine, the net change in the entropy of both reservoirs (hot and cold together) is:

6.

In one cycle of the engine, the net change in the entropy of both reservoirs (hot and cold together) is:

Answer»

In one cycle of the engine, the net change in the entropy of both reservoirs (hot and cold together) is:

Discussion

7.	In the arrangement shown in the fig., the ends P and Q of an un-stretchable string move downwards with uniform speed U. Pulleys A and B are fixed. Mass M moves upwards with a speed?
Answer» In the arrangement shown in the fig., the ends $P$ and $Q$ of an un-stretchable string move downwards with uniform speed $U$ . Pulleys $A$ and $B$ are fixed. Mass $M$ moves upwards with a speed?

7.

In the arrangement shown in the fig., the ends P and Q of an un-stretchable string move downwards with uniform speed U. Pulleys A and B are fixed. Mass M moves upwards with a speed?

Answer»

In the arrangement shown in the fig., the ends $P$ and $Q$ of an un-stretchable string move downwards with uniform speed $U$ . Pulleys $A$ and $B$ are fixed. Mass $M$ moves upwards with a speed?

Discussion

8.	A mass m is suspended at the end of a massless wire of length L and cross – sectional area A. If Y is the Young’s modulus of the material of the wire, the frequency of oscillations along the vertical line is given by
Answer» A mass m is suspended at the end of a massless wire of length L and cross – sectional area A. If Y is the Young’s modulus of the material of the wire, the frequency of oscillations along the vertical line is given by

Discussion

9.	Three identical circular plates of radius R each are placed on a horizontal surface touching one another as shown in the figure. The y coordinate of the center of mass of the system is [Consider A to be at the origin]
Answer» Three identical circular plates of radius $R$ each are placed on a horizontal surface touching one another as shown in the figure. The y coordinate of the center of mass of the system is [Consider $A$ to be at the origin]

Discussion

10.	Figure shows two cylinders of radii r1 andr2 having moments of inertia I1 and I2 about their respective axes. Initially, the cylinders rotate about their axes with angular speeds ω1 and ω2 as shown in the figure. The cylinders are moved closer to touch each other keeping the axes parallel. The cylinders first slip over each other at the contact but the slipping finally ceases due to the friction between them. Find the angular speeds of the cylinder 1 and 2 respectively after the slipping ceases.
Answer» Figure shows two cylinders of radii $r_{1} a n d r_{2}$ having moments of inertia $I_{1} a n d I_{2}$ about their respective axes. Initially, the cylinders rotate about their axes with angular speeds $ω_{1} a n d ω_{2}$ as shown in the figure. The cylinders are moved closer to touch each other keeping the axes parallel. The cylinders first slip over each other at the contact but the slipping finally ceases due to the friction between them. Find the angular speeds of the cylinder 1 and 2 respectively after the slipping ceases.

10.

Figure shows two cylinders of radii r1 andr2 having moments of inertia I1 and I2 about their respective axes. Initially, the cylinders rotate about their axes with angular speeds ω1 and ω2 as shown in the figure. The cylinders are moved closer to touch each other keeping the axes parallel. The cylinders first slip over each other at the contact but the slipping finally ceases due to the friction between them. Find the angular speeds of the cylinder 1 and 2 respectively after the slipping ceases.

Answer»

Figure shows two cylinders of radii $r_{1} a n d r_{2}$ having moments of inertia $I_{1} a n d I_{2}$ about their respective axes. Initially, the cylinders rotate about their axes with angular speeds $ω_{1} a n d ω_{2}$ as shown in the figure. The cylinders are moved closer to touch each other keeping the axes parallel. The cylinders first slip over each other at the contact but the slipping finally ceases due to the friction between them. Find the angular speeds of the cylinder 1 and 2 respectively after the slipping ceases.

Discussion

11.	A shell if projected. At some point it explodes in two parts with mass ratio 1:2. The lighter part falls at origin. What is the distance of other part from origin?
Answer» A shell if projected. At some point it explodes in two parts with mass ratio 1:2. The lighter part falls at origin. What is the distance of other part from origin?

11.

A shell if projected. At some point it explodes in two parts with mass ratio 1:2. The lighter part falls at origin. What is the distance of other part from origin?

Answer»

A shell if projected. At some point it explodes in two parts with mass ratio 1:2. The lighter part falls at origin. What is the distance of other part from origin?

Discussion

12.	An isosceles prism of angle 120∘ has a refractive index 1.44. Two parallel monochromatic rays enter the prism parallel to each other in air as shown in the figure. The rays emerging from the opposite faces.
Answer» An isosceles prism of angle $120^{\circ}$ has a refractive index 1.44. Two parallel monochromatic rays enter the prism parallel to each other in air as shown in the figure. The rays emerging from the opposite faces.

Discussion

13.	An equilateral prism has angle of minimum deviation 30∘ when the angle of incidence is 60∘. The angle of deviation of emergent ray is 10n degrees if the ray is incident normally on a surface. n is (Write upto two digits after the decimal point.)
Answer» An equilateral prism has angle of minimum deviation $30^{\circ}$ when the angle of incidence is $60^{\circ}$ . The angle of deviation of emergent ray is $10 n$ degrees if the ray is incident normally on a surface. n is (Write upto two digits after the decimal point.)

Discussion

14.	A particle starts from rest and moving with an acceleration of 4 ms–2 and covers a distance of 15 m. The final velocity of the particle will be
Answer» A particle starts from rest and moving with an acceleration of $4 {ms}^{- 2}$ and covers a distance of $15 m$ . The final velocity of the particle will be

Discussion

15.	A syringe of diameter 1 cm having a nozzle of diameter 1 mm, is placed horizontally at a height 5 m from the ground. An incompressible, non-viscous liquid is filled in the syringe and the liquid is compressed by moving the piston at a speed of 0.5 ms−1. The horizontal distance travelled by the liquid jet is (g=10 ms−2)
Answer» A syringe of diameter $1 cm$ having a nozzle of diameter $1 mm$ , is placed horizontally at a height $5 m$ from the ground. An incompressible, non-viscous liquid is filled in the syringe and the liquid is compressed by moving the piston at a speed of $0.5 {ms}^{- 1}$ . The horizontal distance travelled by the liquid jet is $(g = 10 {ms}^{- 2})$

Discussion

16.	The displacement due to a wave moving in the positive x - direction is given by y = 1(1+x2) at time t = 0 and by y = 11+(x−1)2 at t = 2 second, where x and y are in metre. The velocity of the wave in m/s is
Answer» The displacement due to a wave moving in the positive x - direction is given by y = $\frac{1}{(1 + x^{2})}$ at time t = 0 and by y = $\frac{1}{1 + {(x - 1)}^{2}}$ at t = 2 second, where x and y are in metre. The velocity of the wave in m/s is

Discussion

17.	Two notes A and B, sounded together, produce 2 beats per second. Notes B and C sounded together produces 3 beats per sec. The notes A and C separately produce the same number of beats with a standard tuning fork of 456 Hz. The possible frequency of the note B is
Answer» Two notes $A$ and $B$ , sounded together, produce $2$ beats per second. Notes $B$ and $C$ sounded together produces $3$ beats per sec. The notes $A$ and $C$ separately produce the same number of beats with a standard tuning fork of $456 Hz$ . The possible frequency of the note $B$ is

Discussion

18.	In the circuit shown in the figure, the ac source gives a voltage V=20 cos(2000 t). Neglecting source resistance, the ammeter reading will be
Answer» In the circuit shown in the figure, the ac source gives a voltage $V = 20 c o s (2000 t)$ . Neglecting source resistance, the ammeter reading will be

Discussion

19.	Let →a and →b are vectors such that \|→a+→b\|=√29 and →a×(2^i+3^j+4^k)=(2^i+3^j+4^k)×→b then (→a+→b).(−7^i+2^j+3^k)=
Answer» Let $\to a$ and $\to b$ are vectors such that $\| \to a + \to b \| = \sqrt{29}$ and $\to a \times (2^i + 3^j + 4^k) = (2^i + 3^j + 4^k) \times \to b$ then $(\to a + \to b) . (- 7^i + 2^j + 3^k) =$

Discussion

20.	A current of 2 A flows in a system of conductors as shown. The potential difference (VA−VB) will be
Answer» A current of 2 A flows in a system of conductors as shown. The potential difference $(V_{A} - V_{B})$ will be

Discussion

21.	Graph shows three waves that are separately sent along a string that is stretched under a certain tension along x-axis. If ω1,ω2 and ω3 are their angular frequencies, respectively, then:
Answer» Graph shows three waves that are separately sent along a string that is stretched under a certain tension along x-axis. If $ω_{1}, ω_{2} a n d ω_{3}$ are their angular frequencies, respectively, then:

Discussion

22.	The moment of inertia of a hollow cubical box of mass M and side ′a′ about an axis passing through the centers of two opposite faces is equal to
Answer» The moment of inertia of a hollow cubical box of mass $M$ and side $^{'} a^{'}$ about an axis passing through the centers of two opposite faces is equal to

Discussion

23.	A body 'A' starts from rest with an acceleration a1. After 2 seconds, another body 'B' starts from rest with an acceleration a2. If they travel equal distances in the 5th second after the start of A, then the ratio a1:a2 is equal to
Answer» A body 'A' starts from rest with an acceleration a₁. After 2 seconds, another body 'B' starts from rest with an acceleration $a_{2}$ . If they travel equal distances in the $5^{t h}$ second after the start of A, then the ratio $a_{1} : a_{2}$ is equal to

Discussion

24.	Two objects that are moving along an xy-plane on a frictionless floor collide. Assume that they form a closed, isolated system. The following table gives some of the momentum components (in kilogram meters per second) before and after the collision. Find the missing values (A, B): Before collisionAfter collisionObjectPx∣PyPx∣PyA−4∣ 53 ∣ABB ∣−24∣2
Answer» Two objects that are moving along an xy-plane on a frictionless floor collide. Assume that they form a closed, isolated system. The following table gives some of the momentum components (in kilogram meters per second) before and after the collision. Find the missing values (A, B): $\begin{matrix} B e f o r e c o l l i s i o n & A f t e r c o l l i s i o n O b j e c t & P_{x} ∣ P_{y} & P_{x} ∣ P_{y} A & - 4 ∣ 5 & 3 ∣ A B & B ∣ - 2 & 4 ∣ 2 \end{matrix}$

Discussion

25.	A resistance of 10 Ω is bent to form a closed circle. What is the effective resistance between the two ends of any diameter of this circuit?
Answer» A resistance of $10 Ω$ is bent to form a closed circle. What is the effective resistance between the two ends of any diameter of this circuit?

Discussion

26.	Calculate the work done in moving a charge −2×10−9 C from A to B via C.
Answer» Calculate the work done in moving a charge $- 2 \times 10^{- 9} C$ from A to B via C.

Discussion

27.	A clock is in x- y plane. Find angular velocity of second hand of a clock (in rad/s).
Answer» A clock is in x- y plane. Find angular velocity of second hand of a clock (in rad/s).

Discussion

28.	If NaCl is doped with 10−4 mole % of SrCl2, the concentration of cation vacancies will be :
Answer» If NaCl is doped with $10^{- 4}$ mole % of $S r C l_{2}$ , the concentration of cation vacancies will be :

Discussion

29.	Two trains A and B simultaneously start moving along parallel tracks from a station along same direction. A starts with constant acceleration 2 m/s2 from rest while B with the same acceleration but with initial velocity of 40 m/s. Twenty seconds after the start, passenger of A hears whistle of B. If frequency of whistle is 1194 Hz and velocity of sound in air is 322 m/s, then the frequency observed by the passenger is
Answer» Two trains $A$ and $B$ simultaneously start moving along parallel tracks from a station along same direction. A starts with constant acceleration $2 {m/s}^{2}$ from rest while $B$ with the same acceleration but with initial velocity of $40 m/s$ . Twenty seconds after the start, passenger of $A$ hears whistle of $B$ . If frequency of whistle is $1194 Hz$ and velocity of sound in air is $322 m/s$ , then the frequency observed by the passenger is

Discussion

30.	An insect wants to go from one corner of cube to diagonaly opposite corner by crawling [can't fly]. Minimum distance it has to travel to reach there if side of cube is a
Answer» An insect wants to go from one corner of cube to diagonaly opposite corner by crawling [can't fly]. Minimum distance it has to travel to reach there if side of cube is a

Discussion

31.	Match List I with List II and select the correct answer. List I(Physical quantity)List II (Dimensions)A. Force1. T−1B. Angular velocity2. MLT−2C. Torque3. ML−1T−2D. Stress4. ML−1T−15. ML2T−2
Answer» Match List I with List II and select the correct answer. $\begin{matrix} List I(Physical quantity) & List II (Dimensions) A. Force & {1. T}^{- 1} B. Angular velocity & {2. MLT}^{- 2} C. Torque & {3. ML}^{- 1} T^{- 2} D. Stress & {4. ML}^{- 1} T^{- 1} {5. ML}^{2} T^{- 2} \end{matrix}$

Discussion

32.	The pair having the same magnetic moment is: [At. No ∴ Cr =24, Mn =25, Fe =26, Co =27]
Answer» The pair having the same magnetic moment is: [At. No $∴$ Cr =24, Mn =25, Fe =26, Co =27]

32.

The pair having the same magnetic moment is: [At. No ∴ Cr =24, Mn =25, Fe =26, Co =27]

Answer»

The pair having the same magnetic moment is:

[At. No $∴$ Cr =24, Mn =25, Fe =26, Co =27]

Discussion

33.	100 g of ice (latent heat 80 cal g−1) at 0∘C is mixed with 100 g of water (specific heat 1 cal g−1 ∘C−1) at 80∘C. The final temperature of the mixture will be
Answer» $100 g$ of ice $(latent heat 80 {cal g}^{- 1})$ at $0^{\circ} C$ is mixed with $100 g$ of water (specific heat $1 {cal g}^{- 1 \circ} C^{- 1}$ ) at $80^{\circ} C$ . The final temperature of the mixture will be

Discussion

34.	A force →F=6x^i+2y^j displaces a body from →r1=3^i+8^j to →r2=5^i−4^j. Find the work done by the force.
Answer» A force $\to F = 6 x^i + 2 y^j$ displaces a body from $_{1} = 3^i + 8^j$ to $_{2} = 5^i - 4^j$ . Find the work done by the force.

Discussion

35.	Difference between propounded theorised and postulated
Answer» Difference between propounded theorised and postulated

Discussion

36.	Two vessels A and B of eual volume V0 are connected by a narrow tube which can be closed by a valve. The vessels are fitted with pistions whi ch can be moved to change the volumes. Initially, the valve is open and the vessels contain an ideal gas (Cp/Cv=γ) at atmospheric pres sure P0 and atmospheric temperature T0. The walls of the vessels A are diathermic and those of B are adiabatic. The valve is now clo sed and the pistons are slowely pulled out to incr ease the volumes of the vessels to double the original value. (a) Find the temperatures and pressures in the two vessels. (b) The valve is now opened for suffiecient time so that the gases acquire a common temperature and pressure. Find the new values of the temper ature and the pressure.
Answer» Two vessels A and B of eual volume $V_{0}$ are connected by a narrow tube which can be closed by a valve. The vessels are fitted with pistions whi ch can be moved to change the volumes. Initially, the valve is open and the vessels contain an ideal gas $(C_{p} / C_{v} = γ)$ at atmospheric pres sure $P_{0}$ and atmospheric temperature $T_{0}$ . The walls of the vessels A are diathermic and those of B are adiabatic. The valve is now clo sed and the pistons are slowely pulled out to incr ease the volumes of the vessels to double the original value. (a) Find the temperatures and pressures in the two vessels. (b) The valve is now opened for suffiecient time so that the gases acquire a common temperature and pressure. Find the new values of the temper ature and the pressure.

36.

Two vessels A and B of eual volume V0 are connected by a narrow tube which can be closed by a valve. The vessels are fitted with pistions whi ch can be moved to change the volumes. Initially, the valve is open and the vessels contain an ideal gas (Cp/Cv=γ) at atmospheric pres sure P0 and atmospheric temperature T0. The walls of the vessels A are diathermic and those of B are adiabatic. The valve is now clo sed and the pistons are slowely pulled out to incr ease the volumes of the vessels to double the original value. (a) Find the temperatures and pressures in the two vessels. (b) The valve is now opened for suffiecient time so that the gases acquire a common temperature and pressure. Find the new values of the temper ature and the pressure.

Answer»

Two vessels A and B of eual volume $V_{0}$ are connected by a narrow tube which can be closed by a valve. The vessels are fitted with pistions whi ch can be moved to change the volumes. Initially, the valve is open and the vessels contain an ideal gas $(C_{p} / C_{v} = γ)$ at atmospheric pres sure $P_{0}$ and atmospheric temperature $T_{0}$ . The walls of the vessels A are diathermic and those of B are adiabatic. The valve is now clo sed and the pistons are slowely pulled out to incr ease the volumes of the vessels to double the original value.

(a) Find the temperatures and pressures in the two vessels.

(b) The valve is now opened for suffiecient time so that the gases acquire a common temperature and pressure. Find the new values of the temper ature and the pressure.

Discussion

37.	An ideal gas is taken through a cyclic thermodynamic process through four steps 1, 2, 3, 4 respectively. The amounts of heat involved in these steps are Q1=5960 J,Q2=5585 J,Q3=−2980 J and Q4=3645 J respectively. The corresponding quantities of work involved are W1=2200 J, W2=8250 J, W3=−1100 J and W4 respectively. The value of W4 is
Answer» An ideal gas is taken through a cyclic thermodynamic process through four steps $1, 2, 3, 4$ respectively. The amounts of heat involved in these steps are $Q_{1} = 5960 J, Q_{2} = 5585 J, Q_{3} = - 2980 J$ and $Q_{4} = 3645 J$ respectively. The corresponding quantities of work involved are $W_{1} = 2200 J, W_{2} = 8250 J, W_{3} = - 1100 J$ and $W_{4}$ respectively. The value of $W_{4}$ is

Discussion

38.	A uniform line charge is moving with a constant velocity v=10 m/s along its axis. It produces an electrostatic field of 9×104 V/m at a perpendicular distance of 1 m from its axis. What will be the current (in μA) due to movement of line charge? Assume that Gauss' Law holds true.
Answer» A uniform line charge is moving with a constant velocity $v = 10 m / s$ along its axis. It produces an electrostatic field of $9 \times 10^{4} V / m$ at a perpendicular distance of $1 m$ from its axis. What will be the current (in $μ A$ ) due to movement of line charge? Assume that Gauss' Law holds true.

Discussion

39.	Why zener current should be sufficiently larger than load current? How does it influence the series resistance?
Answer» Why zener current should be sufficiently larger than load current? How does it influence the series resistance?

Discussion

40.	The level of water in a tank is 5 m high. A hole of area 1 cm2 is made at the bottom of the tank. The rate of leakage of water from the hole is : [Take g=10 m/s2]
Answer» The level of water in a tank is $5 m$ high. A hole of area $1 {cm}^{2}$ is made at the bottom of the tank. The rate of leakage of water from the hole is : [Take $g = 10 {m/s}^{2}$ ]

Discussion

41.	A large slab of mass 5 kg lies on a smooth horizontal surface, with a block of mass 4 kg lying on the top of it. The coefficient of friction between the block and the slab is 0.25. if the block is pulled horizontally by a force of F = 6 N, the work done by the force of friction on the slab, between the instants t=2 s and t=3 s, is (g = 10 ms−2)
Answer» A large slab of mass 5 kg lies on a smooth horizontal surface, with a block of mass 4 kg lying on the top of it. The coefficient of friction between the block and the slab is 0.25. if the block is pulled horizontally by a force of F = 6 N, the work done by the force of friction on the slab, between the instants t=2 s and t=3 s, is (g = 10 m $s^{- 2}$ )

Discussion

42.	A particle is projected vertically upwards from O with velocity v and a second particle is projected at the same instant from P (at a height h above O) with velocity v at an angle of projection θ. The time when the distance between them is minimum is
Answer» A particle is projected vertically upwards from $O$ with velocity $v$ and a second particle is projected at the same instant from $P$ (at a height h above $O$ ) with velocity $v$ at an angle of projection $θ$ . The time when the distance between them is minimum is

Discussion

43.	What is action at a distance force?
Answer» What is action at a distance force?

Discussion

44.	Consider the statements A and B and choose the appropriate option from those given below. A: The position of centre of mass of a body is independent of acceleration due to gravity. B: The center of mass of a body always lies within the boundaries.
Answer» Consider the statements A and B and choose the appropriate option from those given below. A: The position of centre of mass of a body is independent of acceleration due to gravity. B: The center of mass of a body always lies within the boundaries.

44.

Consider the statements A and B and choose the appropriate option from those given below. A: The position of centre of mass of a body is independent of acceleration due to gravity. B: The center of mass of a body always lies within the boundaries.

Answer»

Consider the statements A and B and choose the appropriate option from those given below.

A: The position of centre of mass of a body is independent of acceleration due to gravity.

B: The center of mass of a body always lies within the boundaries.

Discussion

45.	Angular velocities of two bodies rotating in same direction are given by ω1 = 30 rad/sec. ω2 = 60 rad/sec, the relative angular velocity of 2nd body with respect to 1st body is
Answer» Angular velocities of two bodies rotating in same direction are given by $ω_{1}$ = 30 rad/sec. $ω_{2}$ = 60 rad/sec, the relative angular velocity of $2^{n d}$ body with respect to $1^{s t}$ body is

Discussion

46.	A ball is dropped from a height of 5m on to a sandy floor and penetrates the sand 10 cm before coming to rest . Find the retardation of the ball assuming it to be uniform.
Answer» A ball is dropped from a height of 5m on to a sandy floor and penetrates the sand 10 cm before coming to rest . Find the retardation of the ball assuming it to be uniform.

Discussion

47.	Q. Under the action of a force , a 2 kg body moves such that its position x as a function of time t is given by , x=t^2/3 , where x is in metre and t in seconds. The work done by the force in first two seconds is ?
Answer» Q. Under the action of a force , a 2 kg body moves such that its position x as a function of time t is given by , x=t^2/3 , where x is in metre and t in seconds. The work done by the force in first two seconds is ?

Discussion

48.	An object moving with an speed of 25 m/s is decelerating at a rate give by a=−5√v , where, v is speed at any time. The time taken by the object to come at rest is
Answer» An object moving with an speed of $25 m/s$ is decelerating at a rate give by $a = - 5 \sqrt{v},$ where, $v$ is speed at any time. The time taken by the object to come at rest is

Discussion

49.	A particle of mass m is projected from the ground with initial linear momentum p (magnitude) so as to have maximum possible range. Its minimum kinetic energy will be
Answer» A particle of mass $m$ is projected from the ground with initial linear momentum $p$ (magnitude) so as to have maximum possible range. Its minimum kinetic energy will be

Discussion

50.	The diagram shows the electric field lines in a region of space containing two small charged spheres, Y and Z then which statement is true?
Answer» The diagram shows the electric field lines in a region of space containing two small charged spheres, Y and Z then which statement is true?

Discussion

Explore topic-wise InterviewSolutions in Current Affairs.

The unit vector parallel to the resultant of the vectors →A=4^i+3^j+6^k and →B=−^i+3^j−8^k is

A capacitor with stored energy 4 J is connected with an identical capacitor with no electric field in between. Find the total energy stored in the two capacitors.

A uniform chain of mass M and length L is held on a horizontal frictionless table with 1nth of its length hanging over the edge of the table. The work done is pulling the chain up on the table is

A projectile thrown with a speed v at an angle θ has a range R on the surface of earth. For same v and θ, its range on the surface of moon will be

A solid sphere of radius 20 cm is subjected to a uniform pressure of 106 Nm−2. If the bulk modulus of the solid is 1.7×1011 Nm−2, the decrease in the volume of the solid is approximately equal to

In one cycle of the engine, the net change in the entropy of both reservoirs (hot and cold together) is:

In the arrangement shown in the fig., the ends P and Q of an un-stretchable string move downwards with uniform speed U. Pulleys A and B are fixed. Mass M moves upwards with a speed?

A mass m is suspended at the end of a massless wire of length L and cross – sectional area A. If Y is the Young’s modulus of the material of the wire, the frequency of oscillations along the vertical line is given by

Three identical circular plates of radius R each are placed on a horizontal surface touching one another as shown in the figure. The y coordinate of the center of mass of the system is [Consider A to be at the origin]

A shell if projected. At some point it explodes in two parts with mass ratio 1:2. The lighter part falls at origin. What is the distance of other part from origin?

An isosceles prism of angle 120∘ has a refractive index 1.44. Two parallel monochromatic rays enter the prism parallel to each other in air as shown in the figure. The rays emerging from the opposite faces.

An equilateral prism has angle of minimum deviation 30∘ when the angle of incidence is 60∘. The angle of deviation of emergent ray is 10n degrees if the ray is incident normally on a surface. n is (Write upto two digits after the decimal point.)

A particle starts from rest and moving with an acceleration of 4 ms–2 and covers a distance of 15 m. The final velocity of the particle will be

The displacement due to a wave moving in the positive x - direction is given by y = 1(1+x2) at time t = 0 and by y = 11+(x−1)2 at t = 2 second, where x and y are in metre. The velocity of the wave in m/s is

Two notes A and B, sounded together, produce 2 beats per second. Notes B and C sounded together produces 3 beats per sec. The notes A and C separately produce the same number of beats with a standard tuning fork of 456 Hz. The possible frequency of the note B is

In the circuit shown in the figure, the ac source gives a voltage V=20 cos(2000 t). Neglecting source resistance, the ammeter reading will be

Let →a and →b are vectors such that |→a+→b|=√29 and →a×(2^i+3^j+4^k)=(2^i+3^j+4^k)×→b then (→a+→b).(−7^i+2^j+3^k)=

A current of 2 A flows in a system of conductors as shown. The potential difference (VA−VB) will be

Graph shows three waves that are separately sent along a string that is stretched under a certain tension along x-axis. If ω1,ω2 and ω3 are their angular frequencies, respectively, then:

The moment of inertia of a hollow cubical box of mass M and side ′a′ about an axis passing through the centers of two opposite faces is equal to

A body 'A' starts from rest with an acceleration a1. After 2 seconds, another body 'B' starts from rest with an acceleration a2. If they travel equal distances in the 5th second after the start of A, then the ratio a1:a2 is equal to

A resistance of 10 Ω is bent to form a closed circle. What is the effective resistance between the two ends of any diameter of this circuit?

Calculate the work done in moving a charge −2×10−9 C from A to B via C.

A clock is in x- y plane. Find angular velocity of second hand of a clock (in rad/s).

If NaCl is doped with 10−4 mole % of SrCl2, the concentration of cation vacancies will be :

An insect wants to go from one corner of cube to diagonaly opposite corner by crawling [can't fly]. Minimum distance it has to travel to reach there if side of cube is a

Match List I with List II and select the correct answer. List I(Physical quantity)List II (Dimensions)A. Force1. T−1B. Angular velocity2. MLT−2C. Torque3. ML−1T−2D. Stress4. ML−1T−15. ML2T−2

The pair having the same magnetic moment is: [At. No ∴ Cr =24, Mn =25, Fe =26, Co =27]

100 g of ice (latent heat 80 cal g−1) at 0∘C is mixed with 100 g of water (specific heat 1 cal g−1 ∘C−1) at 80∘C. The final temperature of the mixture will be

A force →F=6x^i+2y^j displaces a body from →r1=3^i+8^j to →r2=5^i−4^j. Find the work done by the force.

Difference between propounded theorised and postulated

A uniform line charge is moving with a constant velocity v=10 m/s along its axis. It produces an electrostatic field of 9×104 V/m at a perpendicular distance of 1 m from its axis. What will be the current (in μA) due to movement of line charge? Assume that Gauss' Law holds true.

Why zener current should be sufficiently larger than load current? How does it influence the series resistance?

The level of water in a tank is 5 m high. A hole of area 1 cm2 is made at the bottom of the tank. The rate of leakage of water from the hole is : [Take g=10 m/s2]

A particle is projected vertically upwards from O with velocity v and a second particle is projected at the same instant from P (at a height h above O) with velocity v at an angle of projection θ. The time when the distance between them is minimum is

What is action at a distance force?

Consider the statements A and B and choose the appropriate option from those given below. A: The position of centre of mass of a body is independent of acceleration due to gravity. B: The center of mass of a body always lies within the boundaries.

Angular velocities of two bodies rotating in same direction are given by ω1 = 30 rad/sec. ω2 = 60 rad/sec, the relative angular velocity of 2nd body with respect to 1st body is

A ball is dropped from a height of 5m on to a sandy floor and penetrates the sand 10 cm before coming to rest . Find the retardation of the ball assuming it to be uniform.

Q. Under the action of a force , a 2 kg body moves such that its position x as a function of time t is given by , x=t^2/3 , where x is in metre and t in seconds. The work done by the force in first two seconds is ?

An object moving with an speed of 25 m/s is decelerating at a rate give by a=−5√v , where, v is speed at any time. The time taken by the object to come at rest is

A particle of mass m is projected from the ground with initial linear momentum p (magnitude) so as to have maximum possible range. Its minimum kinetic energy will be

The diagram shows the electric field lines in a region of space containing two small charged spheres, Y and Z then which statement is true?