50278 + Interview Questions in Physics

1.	Find the new resistance of a wire which is stitched n times if its original resistance was R.
Answer» Find the new resistance of a wire which is stitched n times if its original resistance was R.

Discussion

2.	What happens when light travels obliquely from glass to air?
Answer» What happens when light travels obliquely from glass to air?

Discussion

3.	Significant figure of 5×10^3 is same as 5.00×10^3
Answer» Significant figure of 5×10^3 is same as 5.00×10^3

Discussion

4.	KE of a body is increased by 44%. What is thepercent increase in the momentum?(1) 10%(2) 20%ac(3) 30%(4) 44%
Answer» KE of a body is increased by 44%. What is thepercent increase in the momentum?(1) 10%(2) 20%ac(3) 30%(4) 44%

Discussion

5.	A man in a balloon throws a stone downwards with a speed of 5 m/s with respect to balloon. The balloon is moving upwards with a constant acceleration of 5m/s2Then velocity of the stone relative to the man after 2 second is
Answer» A man in a balloon throws a stone downwards with a speed of 5 m/s with respect to balloon. The balloon is moving upwards with a constant acceleration of $5 m / s^{2}$ Then velocity of the stone relative to the man after 2 second is

Discussion

6.	A point moves in a straight line so that its displacement x is given by x2=1+t2 where, x is in m and time t is in s. Its acceleration in m/s2 at time t is
Answer» A point moves in a straight line so that its displacement $x$ is given by $x^{2} = 1 + t^{2}$ where, $x$ is in $m$ and time $t$ is in $s$ . Its acceleration in ${m/s}^{2}$ at time $t$ is

Discussion

7.	When 100 V dc is applied across a solenoid, a current of 1.0 A flows in it. When 100 V ac is applied across the same coil, the current drops to 0.5 A. If the frequency of the ac source is 5o Hz, the impedance and inductance of the solenoid are
Answer» When 100 V dc is applied across a solenoid, a current of 1.0 A flows in it. When 100 V ac is applied across the same coil, the current drops to 0.5 A. If the frequency of the ac source is 5o Hz, the impedance and inductance of the solenoid are

Discussion

8.	In a photoelectric experiment anode potential is plotted against plate current
Answer» In a photoelectric experiment anode potential is plotted against plate current

8.

In a photoelectric experiment anode potential is plotted against plate current

Answer»

In a photoelectric experiment anode potential is plotted against plate current

Discussion

9.	The power factor of an ideal choke coil isOptions: Exactly zero Nearly zero Exactly one Nearly one
Answer» The power factor of an ideal choke coil is Options: Exactly zero Nearly zero Exactly one Nearly one

Discussion

10.	A proton and an α - particle (Helium nucleus) enters a uniform magnetic field with their direction of velocity perpendicular to the direction of magnetic field.(iii) If proton and α - particle enter the magnetic field, perpendicular to it with same momentum, then the ratio of the radii of curvature of proton and α - particle will be[1 Mark]
Answer» A proton and an $α$ - particle (Helium nucleus) enters a uniform magnetic field with their direction of velocity perpendicular to the direction of magnetic field. $(i i i)$ If proton and $α$ - particle enter the magnetic field, perpendicular to it with same momentum, then the ratio of the radii of curvature of proton and $α$ - particle will be $[$ 1 Mark $]$

Discussion

11.	A capacitor of capacity C is charged to potential difference \:and another capacitor of capacity 2C is charged to potential difference 2V. The charging battries are disconected and the two capacitors are connected to each other in parallel with reverse polarity . the energy lost in this process will be.
Answer» A capacitor of capacity C is charged to potential difference \:and another capacitor of capacity 2C is charged to potential difference 2V. The charging battries are disconected and the two capacitors are connected to each other in parallel with reverse polarity . the energy lost in this process will be.

Discussion

12.	The frequency of radiations emitted whenelectron falls from n = 4, to n = 1, in H-atom would be:(GivenE1 for H=2.18×10-18J atom -1 and h=6.625 ×10-34Js.)
Answer» The frequency of radiations emitted when electron falls from n = 4, to n = 1, in H-atom would be: (Given E₁ for H=2.18×10^-18J atom ^-1 and h=6.625 ×10^-34 Js.)

12.

The frequency of radiations emitted whenelectron falls from n = 4, to n = 1, in H-atom would be:(GivenE1 for H=2.18×10-18J atom -1 and h=6.625 ×10-34Js.)

Answer»

The frequency of radiations emitted when
electron falls from n = 4, to n = 1, in H-atom would be:

(Given
E₁ for H=2.18×10^-18J atom ^-1 and h=6.625 ×10^-34
Js.)

Discussion

13.	78.A ball with projection velocity 10m/s is to hit a target 10m away in same horizontal line how high above the target must the ball be aimed so that the ball will hit the target (1)10m (2)102m (3)202m (4)52 m
Answer» 78.A ball with projection velocity 10m/s is to hit a target 10m away in same horizontal line how high above the target must the ball be aimed so that the ball will hit the target (1)10m (2)102m (3)202m (4)52 m

Discussion

14.	distaiceurepicee5. A source emitting sound of frequency 125 Hzisplaced in front of a wall at a distance of 3 m froit. A detector is also placed in front of the wall atsame distance from wall. If the time between thesound received directly from the source and soundreflected from the wall is 8 ms, then find thedistance between source and detector. Speed ofsound in air is 250 m/s.3 m
Answer» distaiceurepicee5. A source emitting sound of frequency 125 Hzisplaced in front of a wall at a distance of 3 m froit. A detector is also placed in front of the wall atsame distance from wall. If the time between thesound received directly from the source and soundreflected from the wall is 8 ms, then find thedistance between source and detector. Speed ofsound in air is 250 m/s.3 m

Discussion

15.	The diameter of a wire of length 50 cm is measured with the help of screw gauge. The main scale reading is 1 mm and circular scale reading is 25. Pitch of the screw gauge is 1 mm and the total number of divisions on the circular scale is 100. This wire is used in an experiment of determination for the Young's modulus of the material of a wire by Scarle's method. The following data are available: elongation in the wire l=0.125 cm under the tension of 50 N, least count for measuring normal length of wire is 0.01 cm and for elongation in the wire is 0.001 cm. The maximum percentage error in calculating the value of Young's mudulus(Y) is n×0.484. Find n. (assuming that the force is measured very accurately, Y=Fl/AΔl where the symbols have their usual meaning)
Answer» The diameter of a wire of length $50 cm$ is measured with the help of screw gauge. The main scale reading is $1 mm$ and circular scale reading is 25. Pitch of the screw gauge is $1 mm$ and the total number of divisions on the circular scale is 100. This wire is used in an experiment of determination for the Young's modulus of the material of a wire by Scarle's method. The following data are available: elongation in the wire $l = 0.125 cm$ under the tension of $50 N$ , least count for measuring normal length of wire is $0.01 cm$ and for elongation in the wire is $0.001 cm$ . The maximum percentage error in calculating the value of Young's mudulus(Y) is $n \times 0.484$ . Find $n$ . (assuming that the force is measured very accurately, $Y = F l / A Δ l$ where the symbols have their usual meaning)

Discussion

16.	Five rods with identical geometries are arranged as shown. Their thermal conductivities are shown. Only A and C are maintained at 100∘C and 0∘C respectively. In other words, heat flows in from A and flows out of C. If temperature difference between ends D and B can be written as 10x∘C, where x is an integer. Then find x.
Answer» Five rods with identical geometries are arranged as shown. Their thermal conductivities are shown. Only A and C are maintained at $100^{\circ} C$ and $0^{\circ} C$ respectively. In other words, heat flows in from A and flows out of C. If temperature difference between ends D and B can be written as $10 x^{\circ} C$ , where $x$ is an integer. Then find $x$ .

Discussion

17.	A small steel ball A is suspended by an inextensible thread of length l=1.5 m from O. Another identical ball is thrown vertically downwards such that its surface remains just in contact with thread during downward motion and collides elastically with the suspended ball. If the suspended ball just completes vertical circle after collision, calculate the velocity (in cm/s) of the falling ball just before collision (g=10 ms−2).
Answer» A small steel ball $A$ is suspended by an inextensible thread of length $l = 1.5 m$ from $O$ . Another identical ball is thrown vertically downwards such that its surface remains just in contact with thread during downward motion and collides elastically with the suspended ball. If the suspended ball just completes vertical circle after collision, calculate the velocity (in $cm/s$ ) of the falling ball just before collision $(g = 10 {ms}^{- 2})$ .

Discussion

18.	The elliptical Lissajous pattern shown in figure was observed from two sinusoidal signal sources of same frequency on a CROThe phase angle between the signal is .....
Answer» The elliptical Lissajous pattern shown in figure was observed from two sinusoidal signal sources of same frequency on a CRO The phase angle between the signal is .....

Discussion

19.	A uniform rod of mass m and length l is hinged at upper end. Rod is free to rotate in vertical plane. A ball of mass m moving horizontally with velocity v0 collides at lower end of rod perpendicular to it and sticks to it. The minimum velocity of the ball such that combined system just completes the vertical circle will beA uniform rod of mass m and length l is hinged at upper end. Rod is free to rotate in vertical plane. A ball of mass m moving horizontally with velocity v0 collides at lower end of rod perpendicular to it and sticks to it. The minimum velocity of the ball such that combined system just completes the vertical circle willbe
Answer» A uniform rod of mass m and length l is hinged at upper end. Rod is free to rotate in vertical plane. A ball of mass m moving horizontally with velocity v0 collides at lower end of rod perpendicular to it and sticks to it. The minimum velocity of the ball such that combined system just completes the vertical circle will beA uniform rod of mass m and length l is hinged at upper end. Rod is free to rotate in vertical plane. A ball of mass m moving horizontally with velocity v0 collides at lower end of rod perpendicular to it and sticks to it. The minimum velocity of the ball such that combined system just completes the vertical circle willbe

Discussion

20.	A cylinder of capacity 20 L is filled with H2 gas. The total average kinetic energy of translatory motion of its molecules is 1.5×105 J. The pressure of hydrogen in the cylinder is
Answer» A cylinder of capacity $20 L$ is filled with $H_{2}$ gas. The total average kinetic energy of translatory motion of its molecules is $1.5 \times 10^{5} J$ . The pressure of hydrogen in the cylinder is

Discussion

21.	If n represents the order of a half period zone, the area of this zone is approximately proportional to nm where m is equal to
Answer» If n represents the order of a half period zone, the area of this zone is approximately proportional to $n^{m}$ where m is equal to

Discussion

22.	A body is projected from ground with some angle to horizontal what happens to the angular momentum about the initial position of motion Answer : increases DOUT: why increases angular momentum remains constant
Answer» A body is projected from ground with some angle to horizontal what happens to the angular momentum about the initial position of motion Answer : increases DOUT: why increases angular momentum remains constant

Discussion

23.	The signal shown below will contain the following non-zero trigonometric Fourier series coefficients
Answer» The signal shown below will contain the following non-zero trigonometric Fourier series coefficients

Discussion

24.	the x and y coordinates of a particle are x=Asin(omegat) and y=Asin(omegat+pi/2).then motion of particle is
Answer» the x and y coordinates of a particle are x=Asin(omegat) and y=Asin(omegat+pi/2).then motion of particle is

Discussion

25.	There are two mass less spring A and B of spring constant KA and KB respectively and KA>KB. If WA and WB be denoted as work done on A and work done on B respectively, then
Answer» There are two mass less spring A and B of spring constant $K_{A}$ and $K_{B}$ respectively and $K_{A} > K_{B}$ . If $W_{A}$ and $W_{B}$ be denoted as work done on A and work done on B respectively, then

Discussion

26.	in uniform circular motion acc\ln is uniform or non nuiform
Answer» in uniform circular motion acc\ln is uniform or non nuiform

Discussion

27.	If 2kJ work is done to increase the velocity of an object from 18 km/hr to 36 km/hr, what is the mass of the object?
Answer» If 2kJ work is done to increase the velocity of an object from 18 km/hr to 36 km/hr, what is the mass of the object?

Discussion

28.	A circuit is made up of a resistance 1 Ω and inductance 0.01 H. An alternating emf of 200 V at 50 Hz is connected, then the phase difference between the current and the emf in the circuit is[1 Mark]
Answer» A circuit is made up of a resistance $1 Ω$ and inductance $0.01 H$ . An alternating emf of $200 V at 50 Hz$ is connected, then the phase difference between the current and the emf in the circuit is $[$ 1 Mark $]$

Discussion

29.	A particle of mass 2 kg moves on a circular path with constant speed 10mm/s find change in speed and magnitude of change in velocity when particle completes half revolution
Answer» A particle of mass 2 kg moves on a circular path with constant speed 10mm/s find change in speed and magnitude of change in velocity when particle completes half revolution

Discussion

30.	A vessel of depth 2h is half filled with a liquid of refractive index 2√2 and the upper half with another liquid of refractive index √2. The liquids are immiscible. The apparent depth of the inner surface of the bottom of the vessel will be:
Answer» A vessel of depth $2 h$ is half filled with a liquid of refractive index $2 \sqrt{2}$ and the upper half with another liquid of refractive index $\sqrt{2}$ . The liquids are immiscible. The apparent depth of the inner surface of the bottom of the vessel will be:

Discussion

31.	A body of mass 10 kg moving on a circular pathwith a uniform speed 10 m/s. Magnitude of change in linear momentum when it turns through the 1/3 rd revolution is
Answer» A body of mass 10 kg moving on a circular pathwith a uniform speed 10 m/s. Magnitude of change in linear momentum when it turns through the 1/3 rd revolution is

Discussion

32.	Which of the following cylindrical rods will conduct most heat, when their ends are maintained at the same steady temperature
Answer» Which of the following cylindrical rods will conduct most heat, when their ends are maintained at the same steady temperature

32.

Which of the following cylindrical rods will conduct most heat, when their ends are maintained at the same steady temperature

Answer»

Which of the following cylindrical rods will conduct most heat, when their ends are maintained at the same steady temperature

Discussion

33.	a thin mettalic strip shee is introduced sheet is moved perpendicularly to plates X and Y of capacitor the capaci†an ce of capacito
Answer» a thin mettalic strip shee is introduced sheet is moved perpendicularly to plates X and Y of capacitor the capaci†an ce of capacito

Discussion

34.	When a plane mirror is placed horizontally on level ground at a distance of 60 m from the foot of a tower, the top of the tower and its image in the mirror subtends an angle of 90∘ at the corner of the mirror nearer to the foot of tower. The height of the tower is
Answer» When a plane mirror is placed horizontally on level ground at a distance of $60 m$ from the foot of a tower, the top of the tower and its image in the mirror subtends an angle of $90^{\circ}$ at the corner of the mirror nearer to the foot of tower. The height of the tower is

Discussion

35.	A simple pendulum has a length l, mass of bob m. The bob is given a charge q coulomb. The pendulum is suspended in a uniform horizontal electric field of strength E as shown in figure, then calculate the time period of oscillation when the bob is slightly displaced from its mean position:
Answer» A simple pendulum has a length $l$ , mass of bob $m$ . The bob is given a charge $q$ coulomb. The pendulum is suspended in a uniform horizontal electric field of strength $E$ as shown in figure, then calculate the time period of oscillation when the bob is slightly displaced from its mean position:

Discussion

36.	Two thin dielectric slabs of dielectric constants k1 and k2 (k1<k2) are inserted between plates of a parallel plate capacitor, as shown in the figure. The variation of electric field E between the plates with distance d as measured from plate P is correctly shown by
Answer» Two thin dielectric slabs of dielectric constants $k_{1}$ and $k_{2}$ $(k_{1} < k_{2})$ are inserted between plates of a parallel plate capacitor, as shown in the figure. The variation of electric field $E$ between the plates with distance $d$ as measured from plate P is correctly shown by

Discussion

37.	A ball of mass 6 kg hits the floor with a speed 2 ms−1 making an angle of incidence 30∘ with the normal. The coefficient of restitution of 13. Find the kinetic energy of ball just after reflection.
Answer» A ball of mass $6 kg$ hits the floor with a speed $2 {ms}^{- 1}$ making an angle of incidence $30^{\circ}$ with the normal. The coefficient of restitution of $\frac{1}{3} .$ Find the kinetic energy of ball just after reflection.

Discussion

38.	A man moving with a velocity of 5 m/s on a horizontal road observes that raindrops fall at an angle of 45∘ with the vertical. When he moves with a velocity of 16 m/s along an inclined plane, which is inclined at 30∘ with the horizontal, he observes raindrops falling vertically downward as shown in the figure. Find the actual velocity →Vr of the raindrops.
Answer» A man moving with a velocity of $5 m/s$ on a horizontal road observes that raindrops fall at an angle of $45^{\circ}$ with the vertical. When he moves with a velocity of $16 m/s$ along an inclined plane, which is inclined at $30^{\circ}$ with the horizontal, he observes raindrops falling vertically downward as shown in the figure. Find the actual velocity ${\to V}_{r}$ of the raindrops.

Discussion

39.	A standing wave is represented by y=asin(0.05x)cos(100t), where t is in second and x,y are in meter, then the velocity of the constituent wave is
Answer» A standing wave is represented by $y = a sin (0.05 x) cos (100 t)$ , where $t$ is in $second$ and $x, y$ are in $meter$ , then the velocity of the constituent wave is

Discussion

40.	A beam of electrons moving at a speed of 106 m/s along a line produces a current of 1.6×10−6A. The number of electrons in the 1 metre of the beam is
Answer» A beam of electrons moving at a speed of $10^{6}$ m/s along a line produces a current of $1.6 \times 10^{- 6} A$ . The number of electrons in the 1 metre of the beam is

Discussion

41.	Derive an expression for K.E of an object. If the velocity of an object is doubled.what will be change in its K.E?
Answer» Derive an expression for K.E of an object. If the velocity of an object is doubled.what will be change in its K.E?

Discussion

42.	In the given figure shows equipotential surfaces, find the magnitude of electric field in the space (in N/C) (Give integer value)
Answer» In the given figure shows equipotential surfaces, find the magnitude of electric field in the space (in N/C) (Give integer value)

Discussion

43.	A rod of mass m =2 kg and length l =3 m rotates about an axis passing through one end O and perpendicular to its length. The other end of rod A, slides without friction on a circular conducting rail (negligible resistance). A resistor R is connected to the rod and rail as shown. The whole set up lies in horizontal plane with uniform magnetic field B directed in to the plane of ring. The rod is given an angular speed ω0 and released. The total heat generated in the resistor R is 27 J. Find the value of ω0 in rad/s.___
Answer» A rod of mass m =2 kg and length l =3 m rotates about an axis passing through one end O and perpendicular to its length. The other end of rod A, slides without friction on a circular conducting rail (negligible resistance). A resistor R is connected to the rod and rail as shown. The whole set up lies in horizontal plane with uniform magnetic field B directed in to the plane of ring. The rod is given an angular speed $ω_{0}$ and released. The total heat generated in the resistor R is 27 J. Find the value of $ω_{0}$ in rad/s.___

Discussion

44.	A body of mass m is pulled along a circular arc by means of a constant horizontal force P as shown. Work done by the force P while lifting the bob from A to B is [l is length of the string and take sin(30o)= 0.5]
Answer» A body of mass m is pulled along a circular arc by means of a constant horizontal force P as shown. Work done by the force P while lifting the bob from A to B is [l is length of the string and take $s i n (30^{o})$ = 0.5]

Discussion

45.	Find the average current for the time interval t=−1 to t=1 s, if the current is given by, i=(6t5+3t2+1) A.
Answer» Find the average current for the time interval $t = - 1$ to $t = 1 s$ , if the current is given by, $i = (6 t^{5} + 3 t^{2} + 1) A$ .

Discussion

46.	A metallic rod is connected between two bodies at temperature Th and Tc (Th>Tc). P,Q and R are the points on the metallic rod along the length (point P being closer to body at temperature Th) where temperature readings are noted as T1,T2 and T3 respectively when the rod has reached steady state. Find the correct option.
Answer» A metallic rod is connected between two bodies at temperature $T_{h}$ and $T_{c} (T_{h} > T_{c})$ . $P, Q$ and $R$ are the points on the metallic rod along the length (point $P$ being closer to body at temperature $T_{h}$ ) where temperature readings are noted as $T_{1}, T_{2}$ and $T_{3}$ respectively when the rod has reached steady state. Find the correct option.

Discussion

47.	Suppose, we think of fission of a 5626Fe nucleus into two equalfragments, 2813 Al . Is the fission energetically possible? Argue byworking out Q of the process. Given m ( 5626Fe ) = 55.93494 u andm ( 2813 Al ) = 27.98191 u.
Answer» Suppose, we think of fission of a 5626Fe nucleus into two equalfragments, 2813 Al . Is the fission energetically possible? Argue byworking out Q of the process. Given m ( 5626Fe ) = 55.93494 u andm ( 2813 Al ) = 27.98191 u.

Discussion

48.	A circular ring of mass 6 kg and radius a is placed such that its centre at the origin. Two particles of masses 2 kg each are placed at the intersecting points of the circle with positive x-axis and positive y-axis. Then, the angle made by the position vector of centre of mass of entire system with x-axis is
Answer» A circular ring of mass $6 kg$ and radius $a$ is placed such that its centre at the origin. Two particles of masses $2 kg$ each are placed at the intersecting points of the circle with positive x-axis and positive y-axis. Then, the angle made by the position vector of centre of mass of entire system with x-axis is

Discussion

49.	The wavelength of Kα X-ray of tungsten is 21.3 pm. It takes 11.3 keV to knock out an electron from the L-shell of a tungsten atom. What should be the minimum accelerating voltage across an X-ray tube having a tungsten target which allows production of Kα X-ray? (hc=1242 eV-nm)
Answer» The wavelength of $K_{α} X-ray$ of tungsten is $21.3 pm$ . It takes $11.3 keV$ to knock out an electron from the $L-shell$ of a tungsten atom. What should be the minimum accelerating voltage across an X-ray tube having a tungsten target which allows production of $K_{α} X-ray$ ? $(h c = 1242 eV-nm)$

Discussion

50.	Centre of mass of three particles of masses 10 Kg, 20 Kg and 30 Kg respectively is at (0,0,0). Where should a particle of mass 40 Kg be placed so that the combined centre of mass will be at (3,3,3)
Answer» Centre of mass of three particles of masses $10 Kg$ , $20 Kg$ and $30 Kg$ respectively is at $(0, 0, 0)$ . Where should a particle of mass $40 Kg$ be placed so that the combined centre of mass will be at $(3, 3, 3)$

Discussion

Explore topic-wise InterviewSolutions in Current Affairs.

Find the new resistance of a wire which is stitched n times if its original resistance was R.

What happens when light travels obliquely from glass to air?

Significant figure of 5×10^3 is same as 5.00×10^3

KE of a body is increased by 44%. What is thepercent increase in the momentum?(1) 10%(2) 20%ac(3) 30%(4) 44%

A man in a balloon throws a stone downwards with a speed of 5 m/s with respect to balloon. The balloon is moving upwards with a constant acceleration of 5m/s2Then velocity of the stone relative to the man after 2 second is

A point moves in a straight line so that its displacement x is given by x2=1+t2 where, x is in m and time t is in s. Its acceleration in m/s2 at time t is

When 100 V dc is applied across a solenoid, a current of 1.0 A flows in it. When 100 V ac is applied across the same coil, the current drops to 0.5 A. If the frequency of the ac source is 5o Hz, the impedance and inductance of the solenoid are

In a photoelectric experiment anode potential is plotted against plate current

The power factor of an ideal choke coil isOptions: Exactly zero Nearly zero Exactly one Nearly one

The frequency of radiations emitted whenelectron falls from n = 4, to n = 1, in H-atom would be:(GivenE1 for H=2.18×10-18J atom -1 and h=6.625 ×10-34Js.)

78.A ball with projection velocity 10m/s is to hit a target 10m away in same horizontal line how high above the target must the ball be aimed so that the ball will hit the target (1)10m (2)102m (3)202m (4)52 m

The elliptical Lissajous pattern shown in figure was observed from two sinusoidal signal sources of same frequency on a CROThe phase angle between the signal is .....

A cylinder of capacity 20 L is filled with H2 gas. The total average kinetic energy of translatory motion of its molecules is 1.5×105 J. The pressure of hydrogen in the cylinder is

If n represents the order of a half period zone, the area of this zone is approximately proportional to nm where m is equal to

A body is projected from ground with some angle to horizontal what happens to the angular momentum about the initial position of motion Answer : increases DOUT: why increases angular momentum remains constant

The signal shown below will contain the following non-zero trigonometric Fourier series coefficients

the x and y coordinates of a particle are x=Asin(omegat) and y=Asin(omegat+pi/2).then motion of particle is

There are two mass less spring A and B of spring constant KA and KB respectively and KA&gt;KB. If WA and WB be denoted as work done on A and work done on B respectively, then

in uniform circular motion acc\ln is uniform or non nuiform

If 2kJ work is done to increase the velocity of an object from 18 km/hr to 36 km/hr, what is the mass of the object?

A circuit is made up of a resistance 1 Ω and inductance 0.01 H. An alternating emf of 200 V at 50 Hz is connected, then the phase difference between the current and the emf in the circuit is​​​​​​​[1 Mark]

A particle of mass 2 kg moves on a circular path with constant speed 10mm/s find change in speed and magnitude of change in velocity when particle completes half revolution

A vessel of depth 2h is half filled with a liquid of refractive index 2√2 and the upper half with another liquid of refractive index √2. The liquids are immiscible. The apparent depth of the inner surface of the bottom of the vessel will be:

A body of mass 10 kg moving on a circular pathwith a uniform speed 10 m/s. Magnitude of change in linear momentum when it turns through the 1/3 rd revolution is

Which of the following cylindrical rods will conduct most heat, when their ends are maintained at the same steady temperature

a thin mettalic strip shee is introduced sheet is moved perpendicularly to plates X and Y of capacitor the capaci†an ce of capacito

When a plane mirror is placed horizontally on level ground at a distance of 60 m from the foot of a tower, the top of the tower and its image in the mirror subtends an angle of 90∘ at the corner of the mirror nearer to the foot of tower. The height of the tower is

A simple pendulum has a length l, mass of bob m. The bob is given a charge q coulomb. The pendulum is suspended in a uniform horizontal electric field of strength E as shown in figure, then calculate the time period of oscillation when the bob is slightly displaced from its mean position:

Two thin dielectric slabs of dielectric constants k1 and k2 (k1&lt;k2) are inserted between plates of a parallel plate capacitor, as shown in the figure. The variation of electric field E between the plates with distance d as measured from plate P is correctly shown by

A ball of mass 6 kg hits the floor with a speed 2 ms−1 making an angle of incidence 30∘ with the normal. The coefficient of restitution of 13. Find the kinetic energy of ball just after reflection.

A standing wave is represented by y=asin(0.05x)cos(100t), where t is in second and x,y are in meter, then the velocity of the constituent wave is

A beam of electrons moving at a speed of 106 m/s along a line produces a current of 1.6×10−6A. The number of electrons in the 1 metre of the beam is

Derive an expression for K.E of an object. If the velocity of an object is doubled.what will be change in its K.E?

In the given figure shows equipotential surfaces, find the magnitude of electric field in the space (in N/C) (Give integer value)

A body of mass m is pulled along a circular arc by means of a constant horizontal force P as shown. Work done by the force P while lifting the bob from A to B is [l is length of the string and take sin(30o)= 0.5]

Find the average current for the time interval t=−1 to t=1 s, if the current is given by, i=(6t5+3t2+1) A.

Suppose, we think of fission of a 5626Fe nucleus into two equalfragments, 2813 Al . Is the fission energetically possible? Argue byworking out Q of the process. Given m ( 5626Fe ) = 55.93494 u andm ( 2813 Al ) = 27.98191 u.

The wavelength of Kα X-ray of tungsten is 21.3 pm. It takes 11.3 keV to knock out an electron from the L-shell of a tungsten atom. What should be the minimum accelerating voltage across an X-ray tube having a tungsten target which allows production of Kα X-ray? (hc=1242 eV-nm)

Centre of mass of three particles of masses 10 Kg, 20 Kg and 30 Kg respectively is at (0,0,0). Where should a particle of mass 40 Kg be placed so that the combined centre of mass will be at (3,3,3)

There are two mass less spring A and B of spring constant KA and KB respectively and KA>KB. If WA and WB be denoted as work done on A and work done on B respectively, then

A circuit is made up of a resistance 1 Ω and inductance 0.01 H. An alternating emf of 200 V at 50 Hz is connected, then the phase difference between the current and the emf in the circuit is[1 Mark]

Two thin dielectric slabs of dielectric constants k1 and k2 (k1<k2) are inserted between plates of a parallel plate capacitor, as shown in the figure. The variation of electric field E between the plates with distance d as measured from plate P is correctly shown by