50278 + Interview Questions in Physics

1.	Two uniform rods of equal length but different masses are rigidly joined to form an L - shaped body which is pivoted about point O as shown. If in the shown configuration, the body is in equillibrium, the ratio M/m will be.
Answer» Two uniform rods of equal length but different masses are rigidly joined to form an $L$ - shaped body which is pivoted about point $O$ as shown. If in the shown configuration, the body is in equillibrium, the ratio $M / m$ will be.

Discussion

2.	How to take an estimate for the value log(1.8)?
Answer» How to take an estimate for the value log(1.8)?

Discussion

3.	A particle is moving along a straight-line path according to the relation S2=at2+2bt+c S represents the displacement covered in t seconds and a,b,c are constants. The acceleration of the particle varies as
Answer» A particle is moving along a straight-line path according to the relation $S^{2} = a t^{2} + 2 b t + c$ $S$ represents the displacement covered in t seconds and $a, b, c$ are constants. The acceleration of the particle varies as

Discussion

4.	A ring of mass 2π kg and of radius 0.25 m is making 300 rpm about an axis through its centre, perpendicular to its plane. The tension (in newtons) developed in the ring is approximately
Answer» A ring of mass $2 π kg$ and of radius $0.25 m$ is making $300 rpm$ about an axis through its centre, perpendicular to its plane. The tension (in newtons) developed in the ring is approximately

Discussion

5.	what is motion under gravity?
Answer» what is motion under gravity?

Discussion

6.	47. If z=1+i/root2 then the value of zto power 1929is
Answer» 47. If z=1+i/root2 then the value of zto power 1929is

Discussion

7.	The electrical resistance in ohms of a certain thermometer varies with temperature according to the approximate law R=R0 [1 +a(T-T0)]The resistance is 101.6at the triple point of water 273.16K and 165.5at the normal melting point of lead (600.5K).What is the temperature when the resistance is 123.4?
Answer» The electrical resistance in ohms of a certain thermometer varies with temperature according to the approximate law R=R0 [1 +a(T-T0)]The resistance is 101.6at the triple point of water 273.16K and 165.5at the normal melting point of lead (600.5K).What is the temperature when the resistance is 123.4?

Discussion

8.	Water flows through the tube shown in figure. The areas of cross section of the wide and the narrow portions of the tube are 5 cm2 and 2 cm2 respectively. The rate of flow of water through the tube is 500 cm3 s-1. Find the difference of mercury levels in the U-tube. Assume this tube lying horizontally on a table.
Answer» Water flows through the tube shown in figure. The areas of cross section of the wide and the narrow portions of the tube are 5 cm² and 2 cm² respectively. The rate of flow of water through the tube is 500 cm³ s^-1. Find the difference of mercury levels in the U-tube. Assume this tube lying horizontally on a table.

8.

Water flows through the tube shown in figure. The areas of cross section of the wide and the narrow portions of the tube are 5 cm2 and 2 cm2 respectively. The rate of flow of water through the tube is 500 cm3 s-1. Find the difference of mercury levels in the U-tube. Assume this tube lying horizontally on a table.

Answer»

Water flows through the tube shown in figure. The areas of cross section of the wide and the narrow portions of the tube are 5 cm² and 2 cm² respectively. The rate of flow of water through the tube is 500 cm³ s^-1. Find the difference of mercury levels in the U-tube. Assume this tube lying horizontally on a table.

Discussion

9.	The electron with charge (q=1.6×10−19 C) moves in an orbit of radius 5×10−11 m with a speed of 2.2×106 ms−1, around an atom. The equivalent current is:
Answer» The electron with charge $(q = 1.6 \times 10^{- 19} C)$ moves in an orbit of radius $5 \times 10^{- 11} m$ with a speed of $2.2 \times 10^{6} {ms}^{- 1}$ , around an atom. The equivalent current is:

Discussion

10.	Focal length of objective lens and eyepiece of an astronomical telescope are 100 cm and 2 cm respectively. Find the angular magnification produced in the case of normal adjustment:
Answer» Focal length of objective lens and eyepiece of an astronomical telescope are $100 cm$ and $2 cm$ respectively. Find the angular magnification produced in the case of normal adjustment:

Discussion

11.	Two waves of intensity I1 and I2 interfere in a medium. If the ratio of maximum intensity produced to the minimum intensity is α, then I1I2 is equal to
Answer» Two waves of intensity $I_{1}$ and $I_{2}$ interfere in a medium. If the ratio of maximum intensity produced to the minimum intensity is $α$ , then $\frac{I_{1}}{I_{2}}$ is equal to

Discussion

12.	A block 1 of mass 0.2 kg sliding to the right over a frictionless elevated surface as shown in the image. The speed of block 1 is 8.00 m/s. The block undergoes an elastic collision with stationary block 2, which is attached to a spring of spring constant 1208.5 N/m. After the collision, block 2 oscillates in SHM with a period of 0.140 s, and block 1 slides off the opposite end of the elevated surface landing at distance d from the base of that surface after falling through height (h=4.90 m). What is the value of d? [Take g=9.8 m/s2]
Answer» A block $1$ of mass $0.2 kg$ sliding to the right over a frictionless elevated surface as shown in the image. The speed of block $1$ is $8.00 m/s$ . The block undergoes an elastic collision with stationary block $2$ , which is attached to a spring of spring constant $1208.5 N/m$ . After the collision, block $2$ oscillates in SHM with a period of $0.140 s$ , and block $1$ slides off the opposite end of the elevated surface landing at distance $d$ from the base of that surface after falling through height $(h = 4.90 m)$ . What is the value of $d$ ? [Take $g = 9.8 {m/s}^{2}$ ]

Discussion

13.	Which of the following is a correct graph of Energy Vs Momentum of the photon?
Answer» Which of the following is a correct graph of Energy Vs Momentum of the photon?

Discussion

14.	A variable force acts on a 1 kg particle such that acceleration as a function of time is given by a=2t. The particle is starting from rest. Find the work done by the force on particle in first 3 seconds.
Answer» A variable force acts on a $1 kg$ particle such that acceleration as a function of time is given by $a = 2 t$ . The particle is starting from rest. Find the work done by the force on particle in first $3$ seconds.

Discussion

15.	Consider a simple RC circuit as shown in Figure 1Process 1 : In the circuit the switch S is closed at t=0 and the capacitor is fully charged to voltage Ve (i.e. charging continues for time T>>RC ). In the process some dissipation (ED) occurs across the resistance R. The amount of energy finally stored in the fully charged capacitor is Ec.Process 2 : In a different process the voltage is first set to V03 and maintained for a charging time T>>RC. Then the voltage is raised to 2V03 without discharging the capacitor and again maintained for a time T>>RC. The process is repeated one more time by raising the voltage to V0 and the capacitor is charged to the same final voltage V0 as in Process 1.These two processes are depicted in Figure 2.In Process 1, the energy stored in the capacitor Ec and heat dissipated across resistance ED are related by
Answer» Consider a simple RC circuit as shown in Figure 1 Process 1 : In the circuit the switch $S$ is closed at $t = 0$ and the capacitor is fully charged to voltage $V_{e}$ (i.e. charging continues for time $T >> R C$ ). In the process some dissipation ( $E_{D}$ ) occurs across the resistance R. The amount of energy finally stored in the fully charged capacitor is $E_{c}$ . Process 2 : In a different process the voltage is first set to $\frac{V_{0}}{3}$ and maintained for a charging time T>>RC. Then the voltage is raised to $\frac{2 V_{0}}{3}$ without discharging the capacitor and again maintained for a time $T >> R C$ . The process is repeated one more time by raising the voltage to $V_{0}$ and the capacitor is charged to the same final voltage $V_{0}$ as in Process $1 .$ These two processes are depicted in Figure 2. In Process 1, the energy stored in the capacitor $E_{c}$ and heat dissipated across resistance $E_{D}$ are related by

15.

Consider a simple RC circuit as shown in Figure 1Process 1 : In the circuit the switch S is closed at t=0 and the capacitor is fully charged to voltage Ve (i.e. charging continues for time T>>RC ). In the process some dissipation (ED) occurs across the resistance R. The amount of energy finally stored in the fully charged capacitor is Ec.Process 2 : In a different process the voltage is first set to V03 and maintained for a charging time T>>RC. Then the voltage is raised to 2V03 without discharging the capacitor and again maintained for a time T>>RC. The process is repeated one more time by raising the voltage to V0 and the capacitor is charged to the same final voltage V0 as in Process 1.These two processes are depicted in Figure 2.In Process 1, the energy stored in the capacitor Ec and heat dissipated across resistance ED are related by

Answer»

Consider a simple RC circuit as shown in Figure 1

Process 1 : In the circuit the switch $S$ is closed at $t = 0$ and the capacitor is fully charged to voltage $V_{e}$ (i.e. charging continues for time $T >> R C$ ). In the process some dissipation ( $E_{D}$ ) occurs across the resistance R. The amount of energy finally stored in the fully charged capacitor is $E_{c}$ .

Process 2 :

In a different process the voltage is first set to $\frac{V_{0}}{3}$ and maintained for a charging time T>>RC. Then the voltage is raised to $\frac{2 V_{0}}{3}$ without discharging the capacitor and again maintained for a time $T >> R C$ . The process is repeated one more time by raising the voltage to $V_{0}$ and the capacitor is charged to the same final voltage $V_{0}$ as in Process $1 .$

These two processes are depicted in Figure 2.

In Process 1, the energy stored in the capacitor $E_{c}$ and heat dissipated across resistance $E_{D}$ are related by

Discussion

16.	Two blocks of masses 10kg and 5kg are connected with the help of massless spring balance in between them.The whole system is placed on the smooth horizontal surface and is pulled with the cons†an t horizontal forces of magnitudes 20N and 10N.The reading of spring balane is
Answer» Two blocks of masses 10kg and 5kg are connected with the help of massless spring balance in between them.The whole system is placed on the smooth horizontal surface and is pulled with the cons†an t horizontal forces of magnitudes 20N and 10N.The reading of spring balane is

Discussion

17.	101. a Proton and an Alpha particle are accelerated through the same potential difference centre in a region of uniform magnetic field with their velocity is perpendicular to the field. compare the radii of circular paths followed by them
Answer» 101. a Proton and an Alpha particle are accelerated through the same potential difference centre in a region of uniform magnetic field with their velocity is perpendicular to the field. compare the radii of circular paths followed by them

Discussion

18.	A series circuit has a resistance of 60 Ω and an impedance of 135 Ω. When the total potential difference is 120 V, the power consumed in the circuit is x W. The value of x is ________.[Round off to the nearest odd integer]
Answer» A series circuit has a resistance of $60 Ω$ and an impedance of $135 Ω$ . When the total potential difference is $120 V$ , the power consumed in the circuit is $x W$ . The value of $x$ is ________. $[$ Round off to the nearest odd integer $]$

Discussion

19.	we have to calculate enery of electron in ev or joule
Answer» we have to calculate enery of electron in ev or joule

Discussion

20.	A thin convex lens is cut into two parts in different ways that are arranged in four manners as shown. Which arrangement will give maximum optical power ?
Answer» A thin convex lens is cut into two parts in different ways that are arranged in four manners as shown. Which arrangement will give maximum optical power ?

Discussion

21.	What shall be the minimum percentage error in velocity if the uncertainty in position is equal to the de Broglie wavelength of a particle?
Answer» What shall be the minimum percentage error in velocity if the uncertainty in position is equal to the de Broglie wavelength of a particle?

Discussion

22.	Two charges −qand +qare located at points (0, 0, −a)and (0, 0, a),respectively.(a) What is the electrostatic potential at the points?(b) Obtainthe dependence of potential on the distance rof a point from the origin when r/a>> 1.(c) Howmuch work is done in moving a small test charge from the point (5, 0,0) to (−7, 0, 0) along the x-axis?Does the answer change if the path of the test charge between thesame points is not along the x-axis?
Answer» Two charges −q and +q are located at points (0, 0, − a) and (0, 0, a), respectively. (a) What is the electrostatic potential at the points? (b) Obtain the dependence of potential on the distance r of a point from the origin when r/a >> 1. (c) How much work is done in moving a small test charge from the point (5, 0, 0) to (−7, 0, 0) along the x-axis? Does the answer change if the path of the test charge between the same points is not along the x-axis?

22.

Two charges −qand +qare located at points (0, 0, −a)and (0, 0, a),respectively.(a) What is the electrostatic potential at the points?(b) Obtainthe dependence of potential on the distance rof a point from the origin when r/a>> 1.(c) Howmuch work is done in moving a small test charge from the point (5, 0,0) to (−7, 0, 0) along the x-axis?Does the answer change if the path of the test charge between thesame points is not along the x-axis?

Answer»

Two charges −q
and +q
are located at points (0, 0, −
a)
and (0, 0, a),
respectively.

(a)
What is the electrostatic potential at the points?

(b) Obtain
the dependence of potential on the distance r
of a point from the origin when r/a
>> 1.

(c) How
much work is done in moving a small test charge from the point (5, 0,
0) to (−7, 0, 0) along the x-axis?
Does the answer change if the path of the test charge between the
same points is not along the x-axis?

Discussion

23.	A particle of mass 2 kg is moving with a uniform speed of 10 m/s in x−y plane along the line x=6 m. Find the magnitude of the angular momentum of the particle about the origin.
Answer» A particle of mass $2 kg$ is moving with a uniform speed of $10 m/s$ in $x - y$ plane along the line $x = 6 m$ . Find the magnitude of the angular momentum of the particle about the origin.

Discussion

24.	As shown in the adjoining figure two charged particles each having charge q and mass m are d distance apart from each other. If two particles are in equilibrium under the gravitational and electrostatic force, then the ratio qm (C/kg) is of the order
Answer» As shown in the adjoining figure two charged particles each having charge $q$ and mass $m$ are $d$ distance apart from each other. If two particles are in equilibrium under the gravitational and electrostatic force, then the ratio $\frac{q}{m} (C / kg)$ is of the order

Discussion

25.	A battery has an open circuit potential difference of 6 V between its terminals. When a load resistance of 60 Ω is connected across the battery, the total power dissipated by the battery is 0.4 W. What should be the load resistance R, so that maximum power will be dissipated in R ?
Answer» A battery has an open circuit potential difference of $6 V$ between its terminals. When a load resistance of $60 Ω$ is connected across the battery, the total power dissipated by the battery is $0.4 W$ . What should be the load resistance $R$ , so that maximum power will be dissipated in $R$ ?

Discussion

26.	A projectile is fired with a speed u at an angle theta above a horizontal feild. The coefficient of restitution of collision between the projectile and the field is e. How far from the starting point, does the projectileakes its second collision with the field?
Answer» A projectile is fired with a speed u at an angle theta above a horizontal feild. The coefficient of restitution of collision between the projectile and the field is e. How far from the starting point, does the projectileakes its second collision with the field?

Discussion

27.	if v is the velocity of a body moving along x axis then accleration of body is
Answer» if v is the velocity of a body moving along x axis then accleration of body is

Discussion

28.	Two identical conducting spheres with negligible volume have 2.1 nC and −0.1 nC charges, respectively. They are brought into contact and then separated by a distance of 0.5 m. The electrostatic force acting between the spheres is _______×10−9 N.[Given : 4πϵ0=19×109 in SI unit]
Answer» Two identical conducting spheres with negligible volume have $2.1 nC$ and $- 0.1 nC$ charges, respectively. They are brought into contact and then separated by a distance of $0.5 m$ . The electrostatic force acting between the spheres is _______ $\times 10^{- 9} N$ . [Given : $4 π ϵ_{0} = \frac{1}{9 \times 10^{9}}$ in SI unit]

Discussion

29.	79. If the electric field is given by 3i+2j+6k . Find the electric flux through a surface area 20unit lying in xy plane
Answer» 79. If the electric field is given by 3i+2j+6k . Find the electric flux through a surface area 20unit lying in xy plane

Discussion

30.	A rough vertical board has an acceleration a so that a 2 kg block pressing against it does not fall. The coefficient of friction between the block and the board is μ. Then,
Answer» A rough vertical board has an acceleration $a$ so that a $2 k g$ block pressing against it does not fall. The coefficient of friction between the block and the board is $μ$ . Then,

Discussion

31.	The frequency changes by 10% as the source approaches a stationary observer with constant speed Vs. What should be the percentage change in frequency as the source recedes from the observer with the same speed? Given that Vs ≪ v(v is the speed of sound in air).
Answer» The frequency changes by 10% as the source approaches a stationary observer with constant speed Vs. What should be the percentage change in frequency as the source recedes from the observer with the same speed? Given that Vs ≪ v(v is the speed of sound in air).

Discussion

32.	An infinitely large charged plane of charge density σ cuts through a spherical surface as shown. Find the flux through the spherical surface.
Answer» An infinitely large charged plane of charge density $σ$ cuts through a spherical surface as shown. Find the flux through the spherical surface.

Discussion

33.	Find the radius of the circle in which a central angle of 60∘ intercepts an arc of length 37.4 cm.(use π=227)
Answer» Find the radius of the circle in which a central angle of $60^{\circ}$ intercepts an arc of length $37.4$ cm. $(use π = \frac{22}{7})$

Discussion

34.	Two blocks of masses 10 kg and 30 kg are placed along a vertical line. The first block is raised through a height of 7 cm. By what distance should the second mass be moved to raise the centre of mass by 1 cm?
Answer» Two blocks of masses 10 kg and 30 kg are placed along a vertical line. The first block is raised through a height of 7 cm. By what distance should the second mass be moved to raise the centre of mass by 1 cm?

34.

Two blocks of masses 10 kg and 30 kg are placed along a vertical line. The first block is raised through a height of 7 cm. By what distance should the second mass be moved to raise the centre of mass by 1 cm?

Answer»

Two blocks of masses 10 kg and 30 kg are placed along a vertical line. The first block is raised through a height of 7 cm. By what distance should the second mass be moved to raise the centre of mass by 1 cm?

Discussion

35.	Find the position , magnification and nagure of the image of an object placedat a dis†an ce of 8cmfrom convex mirror of radius of curvature of 24c
Answer» Find the position , magnification and nagure of the image of an object placedat a dis†an ce of 8cmfrom convex mirror of radius of curvature of 24c

Discussion

36.	what is the change in internal energy when 10 g ice melts
Answer» what is the change in internal energy when 10 g ice melts

Discussion

37.	Two monochromatic light waves of amplitudes A and 2A interfering at a point, have a phase differences of 60∘. The intensity of the resultant wave at that point will be proportional to
Answer» Two monochromatic light waves of amplitudes $A$ and $2 A$ interfering at a point, have a phase differences of $60^{\circ}$ . The intensity of the resultant wave at that point will be proportional to

Discussion

38.	A body is moving with velocity 30 m/s towards east. After 10 seconds its velocity becomes 40 m/s towards north. The average acceleration of the body is
Answer» A body is moving with velocity $30 m/s$ towards east. After $10$ seconds its velocity becomes $40 m/s$ towards north. The average acceleration of the body is

Discussion

39.	A capacitor is charged wit dielectric slab in the soace between the plates of capacitor. the battery is disconnected and the di-electric slab is pulled out of tje space then the force of capacitor upon slab a)- Remains cons†an t b)- increases c)-decreases d)-first increases then decrease
Answer» A capacitor is charged wit dielectric slab in the soace between the plates of capacitor. the battery is disconnected and the di-electric slab is pulled out of tje space then the force of capacitor upon slab a)- Remains cons†an t b)- increases c)-decreases d)-first increases then decrease

Discussion

40.	The current voltage relation of diode is givenby I = (e^{500/T}- 1) mA, where the applied V is in volts and the temperature T is in degree kelvin. If a student makes an error measuring\underset-+ 0.02 V while measuring the current of 7 mA at 200 K, what will be the error in the value ofcurrent in mA?(A) 0.4 mA(C) 0.5 mA(В)0.04m(D) 0.05 mA0
Answer» The current voltage relation of diode is givenby I = (e^{500/T}- 1) mA, where the applied V is in volts and the temperature T is in degree kelvin. If a student makes an error measuring\underset-+ 0.02 V while measuring the current of 7 mA at 200 K, what will be the error in the value ofcurrent in mA?(A) 0.4 mA(C) 0.5 mA(В)0.04m(D) 0.05 mA0

Discussion

41.	8.A 0.1M solution of monobasic acid at specificresistance of r ohms-cm, its molar conductivity is(1) 10/r(2) 10(3) 104/r(4) 10r
Answer» 8. A 0.1M solution of monobasic acid at specific resistance of r ohms-cm, its molar conductivity is (1) 10/r (2) 10 (3) 104/r (4) 10r

Discussion

42.	Resis†an ce of a wire if radius r and length l is R what will be its new resis†an ce if now this wire is made to 4 turbs and radius is r/2
Answer» Resis†an ce of a wire if radius r and length l is R what will be its new resis†an ce if now this wire is made to 4 turbs and radius is r/2

Discussion

43.	Two particles are projected from the same point with the same speed u such that they have the same range R, but different maximum heights, h1 and h2. Which of the following is correct ?
Answer» Two particles are projected from the same point with the same speed $u$ such that they have the same range $R$ , but different maximum heights, $h_{1}$ and $h_{2}$ . Which of the following is correct ?

Discussion

44.	Describe STP.
Answer» Describe STP.

Discussion

45.	A material is embedded between two glass plates. Refractive index n of the material varies thickness as shown. The possible angle(s) of incidence (in degrees) on the material for which the beam will pass through the material is(are)
Answer» A material is embedded between two glass plates. Refractive index $n$ of the material varies thickness as shown. The possible angle(s) of incidence (in degrees) on the material for which the beam will pass through the material is(are)

Discussion

46.	A particle A of mass mA=m2 moving along the x−axis with velocity v0 collides elastically with another particle B at rest having mass mB=m3. If both particle move along the x− axis after the collision. The change Δλ in de-Broglie wavelength of particle A, in terms of its de-Broglie wavelength (λ0) before collision is-
Answer» A particle $A$ of mass $m_{A} = \frac{m}{2}$ moving along the $x -$ axis with velocity $v_{0}$ collides elastically with another particle $B$ at rest having mass $m_{B} = \frac{m}{3}$ . If both particle move along the $x -$ axis after the collision. The change $Δ λ$ in de-Broglie wavelength of particle $A$ , in terms of its de-Broglie wavelength $(λ_{0})$ before collision is-

Discussion

47.	The potential energy function for a particle executing linear simple harmonic motion is given by V(x) = kx²/2, where k is the force constant of the oscillator. For k = 0.5 N m¯¹, the graph of V(x) versus x is shown in Fig. 6.12. Show that a particle of total energy 1 J moving under this potential must ‘turn back’ when it reaches x = ± 2 m.
Answer» The potential energy function for a particle executing linear simple harmonic motion is given by V(x) = kx²/2, where k is the force constant of the oscillator. For k = 0.5 N m¯¹, the graph of V(x) versus x is shown in Fig. 6.12. Show that a particle of total energy 1 J moving under this potential must ‘turn back’ when it reaches x = ± 2 m.

Discussion

48.	The unit vector in the direction of 2^i+3^j+^k is
Answer» The unit vector in the direction of $2^i + 3^j +^k$ is

Discussion

49.	By what distance do the wedges move, if the horizontal plank moves by x cm downwards?
Answer» By what distance do the wedges move, if the horizontal plank moves by $x cm$ downwards?

Discussion

50.	A body dropped from top of a tower fall through 40 m during the last two seconds of its fall. The height of the tower is (g=10 m/s2)
Answer» A body dropped from top of a tower fall through $40 m$ during the last two seconds of its fall. The height of the tower is ( $g = 10 {m/s}^{2}$ )

Discussion

Explore topic-wise InterviewSolutions in Current Affairs.

Two uniform rods of equal length but different masses are rigidly joined to form an L - shaped body which is pivoted about point O as shown. If in the shown configuration, the body is in equillibrium, the ratio M/m will be.

How to take an estimate for the value log(1.8)?

A particle is moving along a straight-line path according to the relation S2=at2+2bt+c S represents the displacement covered in t seconds and a,b,c are constants. The acceleration of the particle varies as

A ring of mass 2π kg and of radius 0.25 m is making 300 rpm about an axis through its centre, perpendicular to its plane. The tension (in newtons) developed in the ring is approximately

what is motion under gravity?

47. If z=1+i/root2 then the value of zto power 1929is

The electron with charge (q=1.6×10−19 C) moves in an orbit of radius 5×10−11 m with a speed of 2.2×106 ms−1, around an atom. The equivalent current is:

Focal length of objective lens and eyepiece of an astronomical telescope are 100 cm and 2 cm respectively. Find the angular magnification produced in the case of normal adjustment:

Two waves of intensity I1 and I2 interfere in a medium. If the ratio of maximum intensity produced to the minimum intensity is α, then I1I2 is equal to

Which of the following is a correct graph of Energy Vs Momentum of the photon?

A variable force acts on a 1 kg particle such that acceleration as a function of time is given by a=2t. The particle is starting from rest. Find the work done by the force on particle in first 3 seconds.

Two blocks of masses 10kg and 5kg are connected with the help of massless spring balance in between them.The whole system is placed on the smooth horizontal surface and is pulled with the cons†an t horizontal forces of magnitudes 20N and 10N.The reading of spring balane is

101. a Proton and an Alpha particle are accelerated through the same potential difference centre in a region of uniform magnetic field with their velocity is perpendicular to the field. compare the radii of circular paths followed by them

A series circuit has a resistance of 60 Ω and an impedance of 135 Ω. When the total potential difference is 120 V, the power consumed in the circuit is x W. The value of x is ________.[Round off to the nearest odd integer]

we have to calculate enery of electron in ev or joule

A thin convex lens is cut into two parts in different ways that are arranged in four manners as shown. Which arrangement will give maximum optical power ?

What shall be the minimum percentage error in velocity if the uncertainty in position is equal to the de Broglie wavelength of a particle?

A particle of mass 2 kg is moving with a uniform speed of 10 m/s in x−y plane along the line x=6 m. Find the magnitude of the angular momentum of the particle about the origin.

As shown in the adjoining figure two charged particles each having charge q and mass m are d distance apart from each other. If two particles are in equilibrium under the gravitational and electrostatic force, then the ratio qm (C/kg) is of the order

A battery has an open circuit potential difference of 6 V between its terminals. When a load resistance of 60 Ω is connected across the battery, the total power dissipated by the battery is 0.4 W. What should be the load resistance R, so that maximum power will be dissipated in R ?

A projectile is fired with a speed u at an angle theta above a horizontal feild. The coefficient of restitution of collision between the projectile and the field is e. How far from the starting point, does the projectileakes its second collision with the field?

if v is the velocity of a body moving along x axis then accleration of body is

Two identical conducting spheres with negligible volume have 2.1 nC and −0.1 nC charges, respectively. They are brought into contact and then separated by a distance of 0.5 m. The electrostatic force acting between the spheres is _______×10−9 N.[Given : 4πϵ0=19×109 in SI unit]

79. If the electric field is given by 3i+2j+6k . Find the electric flux through a surface area 20unit lying in xy plane

A rough vertical board has an acceleration a so that a 2 kg block pressing against it does not fall. The coefficient of friction between the block and the board is μ. Then,

The frequency changes by 10% as the source approaches a stationary observer with constant speed Vs. What should be the percentage change in frequency as the source recedes from the observer with the same speed? Given that Vs ≪ v(v is the speed of sound in air).

An infinitely large charged plane of charge density σ cuts through a spherical surface as shown. Find the flux through the spherical surface.

Find the radius of the circle in which a central angle of 60∘ intercepts an arc of length 37.4 cm.(use π=227)

Two blocks of masses 10 kg and 30 kg are placed along a vertical line. The first block is raised through a height of 7 cm. By what distance should the second mass be moved to raise the centre of mass by 1 cm?

Find the position , magnification and nagure of the image of an object placedat a dis†an ce of 8cmfrom convex mirror of radius of curvature of 24c

what is the change in internal energy when 10 g ice melts

Two monochromatic light waves of amplitudes A and 2A interfering at a point, have a phase differences of 60∘. The intensity of the resultant wave at that point will be proportional to

A body is moving with velocity 30 m/s towards east. After 10 seconds its velocity becomes 40 m/s towards north. The average acceleration of the body is

A capacitor is charged wit dielectric slab in the soace between the plates of capacitor. the battery is disconnected and the di-electric slab is pulled out of tje space then the force of capacitor upon slab a)- Remains cons†an t b)- increases c)-decreases d)-first increases then decrease

8.A 0.1M solution of monobasic acid at specificresistance of r ohms-cm, its molar conductivity is(1) 10/r(2) 10(3) 104/r(4) 10r

Resis†an ce of a wire if radius r and length l is R what will be its new resis†an ce if now this wire is made to 4 turbs and radius is r/2

Two particles are projected from the same point with the same speed u such that they have the same range R, but different maximum heights, h1 and h2. Which of the following is correct ?

Describe STP.

A material is embedded between two glass plates. Refractive index n of the material varies thickness as shown. The possible angle(s) of incidence (in degrees) on the material for which the beam will pass through the material is(are)

The unit vector in the direction of 2^i+3^j+^k is

By what distance do the wedges move, if the horizontal plank moves by x cm downwards?

A body dropped from top of a tower fall through 40 m during the last two seconds of its fall. The height of the tower is (g=10 m/s2)