50278 + Interview Questions in Physics

1.	130. the velocity time equation of a particle moving in a straight line v=2t-4 when t≤2 secs and v=4-2t when t≥2secs the distance travlled by the particle in the time interval between t=0 to t=4secs is?
Answer» 130. the velocity time equation of a particle moving in a straight line v=2t-4 when t≤2 secs and v=4-2t when t≥2secs the distance travlled by the particle in the time interval between t=0 to t=4secs is?

Discussion

2.	A ball of mass 100 g is projected vertically upwards from the ground with a velocity of 49 ms−1. At the same time, another identical ball is dropped from a height of 98 m to fall freely along the same path as followed by the first ball. After sometimes the two balls collide and sticks together. The velocity of the combined mass just after the collision is-[Take g=9.8 ms−2]
Answer» A ball of mass $100 g$ is projected vertically upwards from the ground with a velocity of $49 {ms}^{- 1}$ . At the same time, another identical ball is dropped from a height of $98 m$ to fall freely along the same path as followed by the first ball. After sometimes the two balls collide and sticks together. The velocity of the combined mass just after the collision is- [Take $g = 9.8 {ms}^{- 2}$ ]

Discussion

3.	Two prisms A and B have dispersive powers of 0.012 and 0.018 respectively. The two prisms are incontact with each other. The prism A produces a mean deviation of 1.2∘, what is the mean deviation produced by B if the combination is achromatic?
Answer» Two prisms A and B have dispersive powers of 0.012 and 0.018 respectively. The two prisms are incontact with each other. The prism A produces a mean deviation of ${1.2}^{\circ}$ , what is the mean deviation produced by B if the combination is achromatic?

Discussion

4.	The value of cos210o−cos10ocos50o+cos210o is equal to
Answer» The value of $c o s^{2} 10^{o} - c o s 10^{o} c o s 50^{o} + c o s^{2} 10^{o}$ is equal to

Discussion

5.	68. A solid sphere spinning about a horizontal axis with an angular velocity w is placed on a horizontal surface. Subsequently it rolls without slipping with an angular velocity of (A) 2 w/5 (B) 7 w/5 (C) 2 w/7 (D) w
Answer» 68. A solid sphere spinning about a horizontal axis with an angular velocity w is placed on a horizontal surface. Subsequently it rolls without slipping with an angular velocity of (A) 2 w/5 (B) 7 w/5 (C) 2 w/7 (D) w

Discussion

6.	Which of these can be a possible value for “temperature coefficient of resistivity” of Silicon?
Answer» Which of these can be a possible value for “temperature coefficient of resistivity” of Silicon?

Discussion

7.	A light beam travelling in the X-direction is described by the electric field Ey=(300 V/m)sin ω(t−x/c). An electron is constrained to move along the Y-direction with a speed of 2.0×107 m/s. Find the maximum electric force and the maximum magnetic force on the electron respectively.
Answer» A light beam travelling in the X-direction is described by the electric field $E_{y} = (300 V/m) sin ω (t - x / c) .$ An electron is constrained to move along the Y-direction with a speed of $2.0 \times 10^{7} m/s .$ Find the maximum electric force and the maximum magnetic force on the electron respectively.

Discussion

8.	In a circuit containing an inductance of zero resistance, the e.m.f. of the applied ac voltage leads the current by
Answer» In a circuit containing an inductance of zero resistance, the e.m.f. of the applied ac voltage leads the current by

Discussion

9.	Two cyclic plants with Rankine and brayton cycle are connected is series. Supplementary fining is done before the heat exchange between the condenser of brayton cycle and boiler of Rankine cycle. The fraction of total heat supplied that is used for supplementary heating is 0.2. Efficiency of Rankine cycle and brayton cycle are 30% and 40% respectively. Overall efficiency of plant is _____ %. Take 100% efficiency for heat exchanger. 52.4
Answer» Two cyclic plants with Rankine and brayton cycle are connected is series. Supplementary fining is done before the heat exchange between the condenser of brayton cycle and boiler of Rankine cycle. The fraction of total heat supplied that is used for supplementary heating is 0.2. Efficiency of Rankine cycle and brayton cycle are 30% and 40% respectively. Overall efficiency of plant is _____ %. Take 100% efficiency for heat exchanger. 52.4

Discussion

10.	X-rays of wavelength 22 pm are scatered from a carbon target at an angle of 85 to the incident beamThe Compton shit for X-rays is (cos 850.088)
Answer» X-rays of wavelength 22 pm are scatered from a carbon target at an angle of 85 to the incident beamThe Compton shit for X-rays is (cos 850.088)

Discussion

11.	To solve a problem using lens formula, if object distance, focal length and height of the object is given, the height of the image can be calculated.
Answer» To solve a problem using lens formula, if object distance, focal length and height of the object is given, the height of the image can be calculated.

Discussion

12.	Four identical rods of mass M=6 kg each are welded at their ends to form a square and then welded to a massive ring having mass M=4 kg and radius R=1 m. If the system is allowed to roll down the incline of inclination θ=30∘.The acceleration of the system will be
Answer» Four identical rods of mass $M = 6 kg$ each are welded at their ends to form a square and then welded to a massive ring having mass $M = 4 kg$ and radius $R = 1 m$ . If the system is allowed to roll down the incline of inclination $θ = 30^{\circ}$ . The acceleration of the system will be

Discussion

13.	a wire ring of radius r is in pure rolling on a surface find the EMF induced across the top and bottom points of the ring at any instant if the magnetic field is inside the plane
Answer» a wire ring of radius r is in pure rolling on a surface find the EMF induced across the top and bottom points of the ring at any instant if the magnetic field is inside the plane

Discussion

14.	A flexible chain of length l and mass m is slowly pulled at constant speed up over the edge of a table by a force F parallel to the edge of the table . Assuming that there is no friction between the table and chain , calculate the work done .
Answer» A flexible chain of length l and mass m is slowly pulled at constant speed up over the edge of a table by a force F parallel to the edge of the table . Assuming that there is no friction between the table and chain , calculate the work done .

Discussion

15.	A car sometimes overturns while taking a turn. When it overturns, it is
Answer» A car sometimes overturns while taking a turn. When it overturns, it is

Discussion

16.	A 30 kg boy is riding a merry-go-round. If the linear speed and angular speed of the boy are 6 m/s and 2 rad/s respectively. The magnitude of centripetal force on the boy is
Answer» A $30 kg$ boy is riding a merry-go-round. If the linear speed and angular speed of the boy are $6 m/s$ and $2 rad/s$ respectively. The magnitude of centripetal force on the boy is

Discussion

17.	A thin uniform film of refractive index 1.75 is placed on a sheet of glass of refractive index 1.5. At room temperature (20 ∘C), this film is just thick enough for light with wavelength 600 nm reflected off the top of the film to be canceled by light reflected from top of the glass. After the glass is placed in an oven and slowly heated to 170 ∘C, the film cancels reflected light of wavelength 606 nm. The coefficient of linear expansion of the film is (Ignore any changes in the refractive index of the film due to the temperature change.)
Answer» A thin uniform film of refractive index $1.75$ is placed on a sheet of glass of refractive index $1.5$ . At room temperature $(20^{\circ} C)$ , this film is just thick enough for light with wavelength $600 nm$ reflected off the top of the film to be canceled by light reflected from top of the glass. After the glass is placed in an oven and slowly heated to $170^{\circ} C$ , the film cancels reflected light of wavelength $606 nm$ . The coefficient of linear expansion of the film is (Ignore any changes in the refractive index of the film due to the temperature change.)

Discussion

18.	42. Calculate the electric and magnetic fields produced by the radiation coming from a 100W bulb at a distance of 3 m. Assume that the efficiency of the bulb is 2.5% and it is a point source.
Answer» 42. Calculate the electric and magnetic fields produced by the radiation coming from a 100W bulb at a distance of 3 m. Assume that the efficiency of the bulb is 2.5% and it is a point source.

Discussion

19.	Two particles X and Y having equal charges, after being accelerated through the same potential difference, enter a region of uniform magnetic field and describes circular path of radius R1 and R2 respectively. The ratio of mass of X to that of Y is
Answer» Two particles X and Y having equal charges, after being accelerated through the same potential difference, enter a region of uniform magnetic field and describes circular path of radius $R_{1}$ and $R_{2}$ respectively. The ratio of mass of X to that of Y is

Discussion

20.	In a particular system of unit, if unit of mass becomes half and that of time becomes twice, then 10 joule of work will be written as --- units of work.
Answer» In a particular system of unit, if unit of mass becomes half and that of time becomes twice, then 10 joule of work will be written as --- units of work.

Discussion

21.	34 If the weight of metal oxide is x g and y g of oxygen, the equivalent weight of metal will be 1 E= 8x/y 2 E= 8(y-x)/x 3 E= y/8 4 E=8(x-y)/y
Answer» 34 If the weight of metal oxide is x g and y g of oxygen, the equivalent weight of metal will be 1 E= 8x/y 2 E= 8(y-x)/x 3 E= y/8 4 E=8(x-y)/y

Discussion

22.	A 2100 W continuous flow geyser (instant geyser) has water inlet temperature =10∘C while the water flows out at the rate of 20 g/sec. The outlet temperature of water must be about(Assume that time lag between inlet and outlet flow is 1 s)
Answer» A $2100 W$ continuous flow geyser (instant geyser) has water inlet temperature $= 10^{\circ} C$ while the water flows out at the rate of $20 g/sec$ . The outlet temperature of water must be about (Assume that time lag between inlet and outlet flow is $1 s$ )

Discussion

23.	A narrow beam of singly-charged carbon ions, moving at a constant velocity of 6.0×104 m s−1, is sent perpendicularly in a rectangular region having uniform magnetic field B = 0.5 T (figure 34-E15). It is found that two beams emerge from the field in the backward direction, the separations from the incident beam being 3.0 cm and 3.5 cm. Identify the isotopes present in the ion beam. Take the mass of an ion = A(1.6×10−27) kg, where A is the mass number.
Answer» A narrow beam of singly-charged carbon ions, moving at a constant velocity of $6.0 \times 10^{4} m s^{- 1,}$ is sent perpendicularly in a rectangular region having uniform magnetic field B = 0.5 T (figure 34-E15). It is found that two beams emerge from the field in the backward direction, the separations from the incident beam being 3.0 cm and 3.5 cm. Identify the isotopes present in the ion beam. Take the mass of an ion = $A (1.6 \times 10^{- 27}) k g,$ where A is the mass number.

23.

A narrow beam of singly-charged carbon ions, moving at a constant velocity of 6.0×104 m s−1, is sent perpendicularly in a rectangular region having uniform magnetic field B = 0.5 T (figure 34-E15). It is found that two beams emerge from the field in the backward direction, the separations from the incident beam being 3.0 cm and 3.5 cm. Identify the isotopes present in the ion beam. Take the mass of an ion = A(1.6×10−27) kg, where A is the mass number.

Answer»

A narrow beam of singly-charged carbon ions, moving at a constant velocity of $6.0 \times 10^{4} m s^{- 1,}$ is sent perpendicularly in a rectangular region having uniform magnetic field B = 0.5 T (figure 34-E15). It is found that two beams emerge from the field in the backward direction, the separations from the incident beam being 3.0 cm and 3.5 cm. Identify the isotopes present in the ion beam. Take the mass of an ion = $A (1.6 \times 10^{- 27}) k g,$ where A is the mass number.

Discussion

24.	An electric bulb is rated 220 V and 100 W. When it is operated on 110 V, the power consumed will be −(a) 100 W(b) 75 W(c) 50 W(d) 25 W
Answer» An electric bulb is rated 220 V and 100 W. When it is operated on 110 V, the power consumed will be − (a) 100 W (b) 75 W (c) 50 W (d) 25 W

24.

An electric bulb is rated 220 V and 100 W. When it is operated on 110 V, the power consumed will be −(a) 100 W(b) 75 W(c) 50 W(d) 25 W

Answer»

An electric bulb is rated 220 V and 100 W. When it is operated on 110 V, the power consumed will be −

(a) 100 W

(b) 75 W

(c) 50 W

(d) 25 W

Discussion

25.	Two equal positive point charges q1 = q2 =2.0 μC are located at x = 0, y = 0.30 m and x = 0, y = --0.30 m, respectively. What are themagnitude and the direction of the net electric force that these charges exert on a third point charge Q = 4.0 μC at x = 0.40 m, y = 0?
Answer» Two equal positive point charges q1 = q2 =2.0 μC are located at x = 0, y = 0.30 m and x = 0, y = --0.30 m, respectively. What are the magnitude and the direction of the net electric force that these charges exert on a third point charge Q = 4.0 μC at x = 0.40 m, y = 0?

Discussion

26.	Three sources of sound S1,S2 and S3 of equal intensity are placed in a straight line with S1,S2=S2,S3 (figure 16-E5). At a point P, far away from the sources, the wave coming from S2 is 120∘ ahead in phase of that from S1 Also, the wave coming from S3 is 120∘ ahead of that from S2. What would be the resultant intensity of sound at P?
Answer» Three sources of sound $S_{1}, S_{2}$ and $S_{3}$ of equal intensity are placed in a straight line with $S_{1}, S_{2} = S_{2}, S_{3}$ (figure 16-E5). At a point P, far away from the sources, the wave coming from $S_{2}$ is $120^{\circ}$ ahead in phase of that from $S_{1}$ Also, the wave coming from $S_{3}$ is $120^{\circ}$ ahead of that from $S_{2}$ . What would be the resultant intensity of sound at P?

26.

Three sources of sound S1,S2 and S3 of equal intensity are placed in a straight line with S1,S2=S2,S3 (figure 16-E5). At a point P, far away from the sources, the wave coming from S2 is 120∘ ahead in phase of that from S1 Also, the wave coming from S3 is 120∘ ahead of that from S2. What would be the resultant intensity of sound at P?

Answer»

Three sources of sound $S_{1}, S_{2}$ and $S_{3}$ of equal intensity are placed in a straight line with $S_{1}, S_{2} = S_{2}, S_{3}$ (figure 16-E5). At a point P, far away from the sources, the wave coming from $S_{2}$ is $120^{\circ}$ ahead in phase of that from $S_{1}$ Also, the wave coming from $S_{3}$ is $120^{\circ}$ ahead of that from $S_{2}$ . What would be the resultant intensity of sound at P?

Discussion

27.	A force →F=4^i+3^j+4^K is applied on an intersection point of x=2 plane and x−axis. The magnitude of torque of this force about a point (2,3,4) is (Round off to the Nearest Integer)
Answer» A force $\to F = 4^i + 3^j + 4^K$ is applied on an intersection point of $x = 2$ plane and $x - axis$ . The magnitude of torque of this force about a point $(2, 3, 4)$ is (Round off to the Nearest Integer)

Discussion

28.	98.what is the dimensional formula for stress.?
Answer» 98.what is the dimensional formula for stress.?

Discussion

29.	A bar magnet of length 3 cm has points A and B along its axis at distances of 24 cm and 48 cm from its centre on the opposite sides, the ratio of magnetic fields at the points will be
Answer» A bar magnet of length $3 cm$ has points $A$ and $B$ along its axis at distances of $24 cm$ and $48 cm$ from its centre on the opposite sides, the ratio of magnetic fields at the points will be

Discussion

30.	Question 5A girl is carrying a school bag 3 kg on her back and moves 200 m on a leveled road. The work done against the gravitational force will be (g=10 ms−2)(a) 6×103 J(b) 6 J(c) 0.6 J(d) zero
Answer» Question 5 A girl is carrying a school bag 3 kg on her back and moves 200 m on a leveled road. The work done against the gravitational force will be $(g = 10 m s^{- 2})$ (a) $6 \times 10^{3}$ J (b) 6 J (c) 0.6 J (d) zero

Discussion

31.	Q) A particle is moving in a circle of radius 20 cm. Its linear speed is given by v = 2t, where t is in second and v is in ms–1. Then the angle between velocity and the acceleration of the particle at t = 2 s is
Answer» Q) A particle is moving in a circle of radius 20 cm. Its linear speed is given by v = 2t, where t is in second and v is in ms–1. Then the angle between velocity and the acceleration of the particle at t = 2 s is

Discussion

32.	81.A ring of radius R and mass M =2kg has charge q1=+2C and q2=-2 C on diametrically opposite points. It remains in equilibrium on a rougj inclined plane in the presence of uniform electric field E then magnitude of E is
Answer» 81.A ring of radius R and mass M =2kg has charge q1=+2C and q2=-2 C on diametrically opposite points. It remains in equilibrium on a rougj inclined plane in the presence of uniform electric field E then magnitude of E is

Discussion

33.	A uniform rod of mass m and length l can rotate in a vertical plane about a smooth horizontal axis hinged at point H. Find the force exerted by the hinge just after the rod is released as shown in the figure.
Answer» A uniform rod of mass $m$ and length $l$ can rotate in a vertical plane about a smooth horizontal axis hinged at point $H$ . Find the force exerted by the hinge just after the rod is released as shown in the figure.

Discussion

34.	Consider the region of electric field, as shown in the figure. Work done by the electric field, in carrying a protonfrom point B to point A, will be4.VA 10 VVB 20 V(1) 1.610-18J(3) 1.6 x 10-19 J(2)(4)-1.610-18J-1.6 x 10-19 Jsh Educational Saricoo Lt
Answer» Consider the region of electric field, as shown in the figure. Work done by the electric field, in carrying a protonfrom point B to point A, will be4.VA 10 VVB 20 V(1) 1.610-18J(3) 1.6 x 10-19 J(2)(4)-1.610-18J-1.6 x 10-19 Jsh Educational Saricoo Lt

Discussion

35.	Two planets of same density, have radii R1 and R2 such that R1=2R2. If the escape velocity on the planets are v1 and v2 respectively. Then ratio v2v1 is equal to
Answer» Two planets of same density, have radii $R_{1}$ and $R_{2}$ such that $R_{1} = 2 R_{2}$ . If the escape velocity on the planets are $v_{1}$ and $v_{2}$ respectively. Then ratio $\frac{v_{2}}{v_{1}}$ is equal to

Discussion

36.	A double star is a system of two stars rotating about their centre of mass only under their mutual gravitational attraction. Let the stars have masses m and 2m and let their separation be l. Their time period of rotation about their centre of mass will be proportional to
Answer» A double star is a system of two stars rotating about their centre of mass only under their mutual gravitational attraction. Let the stars have masses m and 2m and let their separation be $l$ . Their time period of rotation about their centre of mass will be proportional to

Discussion

37.	A small block is connected to a massless rod placed on a fulcrum, which in turn is attached to a spring of force constant k as shown in the figure. The block is displaced down slightly, and left free. Find time period of small oscillations.
Answer» A small block is connected to a massless rod placed on a fulcrum, which in turn is attached to a spring of force constant $k$ as shown in the figure. The block is displaced down slightly, and left free. Find time period of small oscillations.

Discussion

38.	If momentum of an object is increased by 10 % then its kinetic energy will increase by4.(1) 20%(2) 21%(3) 40%(4) 19%
Answer» If momentum of an object is increased by 10 % then its kinetic energy will increase by4.(1) 20%(2) 21%(3) 40%(4) 19%

Discussion

39.	Two containers A and B contain ideal gases, helium and oxygen respectively. Volume of both containers are equal, and pressure is also equal. Container A has twice the number of molecules than container B. If VA and VB represent the rms speed of gases in containers A and B respectively, then
Answer» Two containers $A and B$ contain ideal gases, helium and oxygen respectively. Volume of both containers are equal, and pressure is also equal. Container $A$ has twice the number of molecules than container $B .$ If $V_{A} and V_{B}$ represent the rms speed of gases in containers $A and B$ respectively, then

Discussion

40.	An object is projected with speed 50 m/s at an angle 53∘ with horizontal from ground. The radius of curvature of its trajectory at t=1 sec after projection will be:(Take g=10 m/s2)
Answer» An object is projected with speed $50 m/s$ at an angle $53^{\circ}$ with horizontal from ground. The radius of curvature of its trajectory at $t = 1 sec$ after projection will be: $($ Take $g = 10 {m/s}^{2})$

Discussion

41.	A helicopter is flying on a height of 1500 m. Due to climate change, the pilot of the helicopter has decided to land on a helipad which is just below the helicopter at a height of 600 m from the ground. Taking upward movement of helicopter as positive and downward movement as negative. Find the distance of helipad from the helicopter? [4 MARKS]
Answer» A helicopter is flying on a height of 1500 m. Due to climate change, the pilot of the helicopter has decided to land on a helipad which is just below the helicopter at a height of 600 m from the ground. Taking upward movement of helicopter as positive and downward movement as negative. Find the distance of helipad from the helicopter? [4 MARKS]

Discussion

42.	Two objects A and B start moving on a straight road from same point having initially velocity of 40 m/s and 80 m/s respectively. Both applies brake at this instant, retard constantly with 10m/s^2, when object A is at three fourth of its stopping distance. The difference between the displacement of A and B is
Answer» Two objects A and B start moving on a straight road from same point having initially velocity of 40 m/s and 80 m/s respectively. Both applies brake at this instant, retard constantly with 10m/s^2, when object A is at three fourth of its stopping distance. The difference between the displacement of A and B is

Discussion

43.	Justify why a solid conductor expand on heating.
Answer» Justify why a solid conductor expand on heating.

Discussion

44.	A solid sphere of mass m radius r is placed inside a hollow thin spherical shell of mass M and radius R as shown in figure. A particle of mass m′ is placed on the line joining the two centres at a distance x from the point of contact of the sphere and the shell. Find the magnitude of the resultant gravitational force on this particle due to the sphere and the shell if r<x<2r.
Answer» A solid sphere of mass $m$ radius $r$ is placed inside a hollow thin spherical shell of mass $M$ and radius $R$ as shown in figure. A particle of mass $m^{'}$ is placed on the line joining the two centres at a distance $x$ from the point of contact of the sphere and the shell. Find the magnitude of the resultant gravitational force on this particle due to the sphere and the shell if $r < x < 2 r$ .

Discussion

45.	Two particles of same mass 2 kg are rigidly attached to the ends of a massless rod of length 10 m. The rod is clamped at the centre such that the system rotates about the perpendicular bisector of the rod at an angular speed 10 rad/s. Calculate the magnitude of angular momentum of the system about the axis of rotation [in kg m2/s]
Answer» Two particles of same mass $2 kg$ are rigidly attached to the ends of a massless rod of length $10 m$ . The rod is clamped at the centre such that the system rotates about the perpendicular bisector of the rod at an angular speed $10 rad/s$ . Calculate the magnitude of angular momentum of the system about the axis of rotation [in ${kg m}^{2} /s$ ]

Discussion

46.	Fourth equation of motion
Answer» Fourth equation of motion

Discussion

47.	Two identical cells, each of emf E, having negligible internal resistance, are connected in parallel with each other across an external resistance R. What is the current through this resistance ?
Answer» Two identical cells, each of emf E, having negligible internal resistance, are connected in parallel with each other across an external resistance R. What is the current through this resistance ?

Discussion

48.	Which of the following graphs represent the variation of mechanical efficiency v/s brake power of the engine ?
Answer» Which of the following graphs represent the variation of mechanical efficiency v/s brake power of the engine ?

Discussion

49.	Certain force acting on a 20 kg of mass changes its velocity from 5m/s to 2 m/s. Calculate the work done by the force.
Answer» Certain force acting on a 20 kg of mass changes its velocity from 5m/s to 2 m/s. Calculate the work done by the force.

Discussion

50.	When a car is at rest, its driver sees raindrops falling on it vertically. When driving the car with speed v, he sees that raindrops are coming at an angle 60∘ from the horizontal. On further increasing the speed of the car to (1+β)v, this angle changes to 45∘. The value of β is close to :
Answer» When a car is at rest, its driver sees raindrops falling on it vertically. When driving the car with speed $v,$ he sees that raindrops are coming at an angle $60^{\circ}$ from the horizontal. On further increasing the speed of the car to $(1 + β) v,$ this angle changes to $45^{\circ}$ . The value of $β$ is close to :

Discussion

Explore topic-wise InterviewSolutions in Current Affairs.

130. the velocity time equation of a particle moving in a straight line v=2t-4 when t≤2 secs and v=4-2t when t≥2secs the distance travlled by the particle in the time interval between t=0 to t=4secs is?

Two prisms A and B have dispersive powers of 0.012 and 0.018 respectively. The two prisms are incontact with each other. The prism A produces a mean deviation of 1.2∘, what is the mean deviation produced by B if the combination is achromatic?

The value of cos210o−cos10ocos50o+cos210o is equal to

68. A solid sphere spinning about a horizontal axis with an angular velocity w is placed on a horizontal surface. Subsequently it rolls without slipping with an angular velocity of (A) 2 w/5 (B) 7 w/5 (C) 2 w/7 (D) w

Which of these can be a possible value for “temperature coefficient of resistivity” of Silicon?

A light beam travelling in the X-direction is described by the electric field Ey=(300 V/m)sin ω(t−x/c). An electron is constrained to move along the Y-direction with a speed of 2.0×107 m/s. Find the maximum electric force and the maximum magnetic force on the electron respectively.

In a circuit containing an inductance of zero resistance, the e.m.f. of the applied ac voltage leads the current by

X-rays of wavelength 22 pm are scatered from a carbon target at an angle of 85 to the incident beamThe Compton shit for X-rays is (cos 850.088)

To solve a problem using lens formula, if object distance, focal length and height of the object is given, the height of the image can be calculated.

Four identical rods of mass M=6 kg each are welded at their ends to form a square and then welded to a massive ring having mass M=4 kg and radius R=1 m. If the system is allowed to roll down the incline of inclination θ=30∘.The acceleration of the system will be

a wire ring of radius r is in pure rolling on a surface find the EMF induced across the top and bottom points of the ring at any instant if the magnetic field is inside the plane

A flexible chain of length l and mass m is slowly pulled at constant speed up over the edge of a table by a force F parallel to the edge of the table . Assuming that there is no friction between the table and chain , calculate the work done .

A car sometimes overturns while taking a turn. When it overturns, it is

A 30 kg boy is riding a merry-go-round. If the linear speed and angular speed of the boy are 6 m/s and 2 rad/s respectively. The magnitude of centripetal force on the boy is

42. Calculate the electric and magnetic fields produced by the radiation coming from a 100W bulb at a distance of 3 m. Assume that the efficiency of the bulb is 2.5% and it is a point source.

Two particles X and Y having equal charges, after being accelerated through the same potential difference, enter a region of uniform magnetic field and describes circular path of radius R1 and R2 respectively. The ratio of mass of X to that of Y is

In a particular system of unit, if unit of mass becomes half and that of time becomes twice, then 10 joule of work will be written as --- units of work.

34 If the weight of metal oxide is x g and y g of oxygen, the equivalent weight of metal will be 1 E= 8x/y 2 E= 8(y-x)/x 3 E= y/8 4 E=8(x-y)/y

A 2100 W continuous flow geyser (instant geyser) has water inlet temperature =10∘C while the water flows out at the rate of 20 g/sec. The outlet temperature of water must be about(Assume that time lag between inlet and outlet flow is 1 s)

An electric bulb is rated 220 V and 100 W. When it is operated on 110 V, the power consumed will be −(a) 100 W(b) 75 W(c) 50 W(d) 25 W

Two equal positive point charges q1 = q2 =2.0 μC are located at x = 0, y = 0.30 m and x = 0, y = --0.30 m, respectively. What are themagnitude and the direction of the net electric force that these charges exert on a third point charge Q = 4.0 μC at x = 0.40 m, y = 0?

A force →F=4^i+3^j+4^K is applied on an intersection point of x=2 plane and x−axis. The magnitude of torque of this force about a point (2,3,4) is (Round off to the Nearest Integer)

98.what is the dimensional formula for stress.?

A bar magnet of length 3 cm has points A and B along its axis at distances of 24 cm and 48 cm from its centre on the opposite sides, the ratio of magnetic fields at the points will be

Question 5A girl is carrying a school bag 3 kg on her back and moves 200 m on a leveled road. The work done against the gravitational force will be (g=10 ms−2)(a) 6×103 J(b) 6 J(c) 0.6 J(d) zero

Q) A particle is moving in a circle of radius 20 cm. Its linear speed is given by v = 2t, where t is in second and v is in ms–1. Then the angle between velocity and the acceleration of the particle at t = 2 s is

81.A ring of radius R and mass M =2kg has charge q1=+2C and q2=-2 C on diametrically opposite points. It remains in equilibrium on a rougj inclined plane in the presence of uniform electric field E then magnitude of E is

A uniform rod of mass m and length l can rotate in a vertical plane about a smooth horizontal axis hinged at point H. Find the force exerted by the hinge just after the rod is released as shown in the figure.

Consider the region of electric field, as shown in the figure. Work done by the electric field, in carrying a protonfrom point B to point A, will be4.VA 10 VVB 20 V(1) 1.610-18J(3) 1.6 x 10-19 J(2)(4)-1.610-18J-1.6 x 10-19 Jsh Educational Saricoo Lt

Two planets of same density, have radii R1 and R2 such that R1=2R2. If the escape velocity on the planets are v1 and v2 respectively. Then ratio v2v1 is equal to

A double star is a system of two stars rotating about their centre of mass only under their mutual gravitational attraction. Let the stars have masses m and 2m and let their separation be l. Their time period of rotation about their centre of mass will be proportional to

A small block is connected to a massless rod placed on a fulcrum, which in turn is attached to a spring of force constant k as shown in the figure. The block is displaced down slightly, and left free. Find time period of small oscillations.

If momentum of an object is increased by 10 % then its kinetic energy will increase by4.(1) 20%(2) 21%(3) 40%(4) 19%

Two containers A and B contain ideal gases, helium and oxygen respectively. Volume of both containers are equal, and pressure is also equal. Container A has twice the number of molecules than container B. If VA and VB represent the rms speed of gases in containers A and B respectively, then

An object is projected with speed 50 m/s at an angle 53∘ with horizontal from ground. The radius of curvature of its trajectory at t=1 sec after projection will be:(Take g=10 m/s2)

Justify why a solid conductor expand on heating.

Fourth equation of motion

Two identical cells, each of emf E, having negligible internal resistance, are connected in parallel with each other across an external resistance R. What is the current through this resistance ?

Which of the following graphs represent the variation of mechanical efficiency v/s brake power of the engine ?

Certain force acting on a 20 kg of mass changes its velocity from 5m/s to 2 m/s. Calculate the work done by the force.

When a car is at rest, its driver sees raindrops falling on it vertically. When driving the car with speed v, he sees that raindrops are coming at an angle 60∘ from the horizontal. On further increasing the speed of the car to (1+β)v, this angle changes to 45∘. The value of β is close to :