50278 + Interview Questions in Physics

1.	1 m3 water is brought inside the lake upto 200 metres depth from the surface of the lake. What will be change in the volume when the bulk modulus of elasticity of water is 22000 atmosphere? (density of water is 1×103 kg/m3, atmosphere pressure =105 N/m2 and g=10 m/s2)
Answer» $1 m^{3}$ water is brought inside the lake upto $200$ metres depth from the surface of the lake. What will be change in the volume when the bulk modulus of elasticity of water is $22000$ atmosphere? (density of water is $1 \times 10^{3} {kg/m}^{3}$ , atmosphere pressure $= 10^{5} {N/m}^{2}$ and $g = 10 {m/s}^{2}$ )

Discussion

2.	The displacement time graph of two moving particles make angles of 30∘ and 45∘ with the X- axis is shown. The ratio of their velocities is:
Answer» The displacement time graph of two moving particles make angles of $30^{\circ}$ and $45^{\circ}$ with the X- axis is shown. The ratio of their velocities is:

Discussion

3.	The value of √rr1r2r32Rr(sinA+sinB+sinC) is equal to:
Answer» The value of $\frac{\sqrt{r r_{1} r_{2} r_{3}}}{2 R r (sin A + sin B + sin C)}$ is equal to:

Discussion

4.	Gravitational field intensity due to a disc
Answer» Gravitational field intensity due to a disc

Discussion

5.	If the units of force and length are doubled then the numerical value of energy will be?
Answer» If the units of force and length are doubled then the numerical value of energy will be?

Discussion

6.	Fringe width observed in the Young's double-slit experiment is β . If the frequency of the source is doubled, the fringe width will
Answer» Fringe width observed in the Young's double-slit experiment is $β$ . If the frequency of the source is doubled, the fringe width will

Discussion

7.	The speed of a particle moving in a circle of radius r = 2 m varies with time t as v=t2 where t is in second and v in m/s. The net acceleration at t =2 s is
Answer» The speed of a particle moving in a circle of radius r = 2 m varies with time t as $v = t^{2}$ where t is in second and v in m/s. The net acceleration at t =2 s is

Discussion

8.	Find the maximum electric field due to a uniformly charged ring of charge Q and radius R along the axis of the ring [K=14πϵ0]
Answer» Find the maximum electric field due to a uniformly charged ring of charge $Q$ and radius $R$ along the axis of the ring $[K = \frac{1}{4 π ϵ_{0}}]$

Discussion

9.	Two wires A and B of the same material, having radii in the ratio 1 : 2 and carry currents in the ratio 4 : 1. The ratio of drift speeds of electrons in A and B is:
Answer» Two wires A and B of the same material, having radii in the ratio 1 : 2 and carry currents in the ratio 4 : 1. The ratio of drift speeds of electrons in A and B is:

Discussion

10.	A solid cylinder of mass M and radius R rolls down an inclined plane of height h. The angular velocity of the cylinder when it reaches the bottom of the plane will be
Answer» A solid cylinder of mass $M$ and radius $R$ rolls down an inclined plane of height $h$ . The angular velocity of the cylinder when it reaches the bottom of the plane will be

Discussion

11.	A stone of mass m is pushed down a frictionless hemispherical bowl of radius r from a point O. The stone just rises upto the half of other side of the bowl as shown in the figure, what is the initial speed of stone with which it was pushed?
Answer» A stone of mass $m$ is pushed down a frictionless hemispherical bowl of radius $r$ from a point O. The stone just rises upto the half of other side of the bowl as shown in the figure, what is the initial speed of stone with which it was pushed?

11.

A stone of mass m is pushed down a frictionless hemispherical bowl of radius r from a point O. The stone just rises upto the half of other side of the bowl as shown in the figure, what is the initial speed of stone with which it was pushed?

Answer»

A stone of mass $m$ is pushed down a frictionless hemispherical bowl of radius $r$ from a point O. The stone just rises upto the half of other side of the bowl as shown in the figure, what is the initial speed of stone with which it was pushed?

Discussion

12.	Find the angular impulse applied to the particle in the 4 sec.
Answer» Find the angular impulse applied to the particle in the 4 sec.

Discussion

13.	Two capacitors each having capacitance 3 μF and breakdown voltage 6 V are joined together in parallel connection. The breakdown voltage of the combination will be :
Answer» Two capacitors each having capacitance $3 μ F$ and breakdown voltage $6 V$ are joined together in parallel connection. The breakdown voltage of the combination will be :

Discussion

14.	A particle of mass m is moving along the x-axis with initial velocity u^i. It collides elastically with a particle of mass 10m at rest and then moves with half its initial kinetic energy (see figure). If sinθ0=√nsinθ2, then value of n is
Answer» A particle of mass $m$ is moving along the x-axis with initial velocity $u^i$ . It collides elastically with a particle of mass $10 m$ at rest and then moves with half its initial kinetic energy (see figure). If $sin θ_{0} = \sqrt{n} sin θ_{2}$ , then value of $n$ is

Discussion

15.	what will be the v_{e }from a planet having velocity 27 times that of earth and the same mean density as that of the earth.
Answer» what will be the v_{e }from a planet having velocity 27 times that of earth and the same mean density as that of the earth.

Discussion

16.	What is value of potential inside a uniformly charged conducting sphere?
Answer» What is value of potential inside a uniformly charged conducting sphere?

Discussion

17.	A block of mass 2M is attached to a massless spring with spring constant k. This block is connected to two other blocks of masses M and 2M using two massless pulleys and strings. The accelerations of the blocks are a1,a2 and a3 as shown in the figure. The system is released from rest with the spring in its unstretched state. The maximum extension of the spring is x0. Which of the following option(s) is/are correct?[g is the acceleration due to gravity. Neglect friction]
Answer» A block of mass 2 $M$ is attached to a massless spring with spring constant $k$ . This block is connected to two other blocks of masses $M$ and $2 M$ using two massless pulleys and strings. The accelerations of the blocks are $a_{1}, a_{2}$ and $a_{3}$ as shown in the figure. The system is released from rest with the spring in its unstretched state. The maximum extension of the spring is $x_{0}$ . Which of the following option(s) is/are correct? [ $g$ is the acceleration due to gravity. Neglect friction]

Discussion

18.	The given truth table is forInputOutputA ∣ BY0 ∣ 010 ∣ 111 ∣ 011 ∣ 10
Answer» The given truth table is for $\begin{matrix} I n p u t & O u t p u t A ∣ B & Y 0 ∣ 0 & 1 0 ∣ 1 & 1 1 ∣ 0 & 1 1 ∣ 1 & 0 \end{matrix}$

18.

The given truth table is forInputOutputA ∣ BY0 ∣ 010 ∣ 111 ∣ 011 ∣ 10

Answer»

The given truth table is for

$\begin{matrix} I n p u t & O u t p u t A ∣ B & Y 0 ∣ 0 & 1 0 ∣ 1 & 1 1 ∣ 0 & 1 1 ∣ 1 & 0 \end{matrix}$

Discussion

19.	A long, cylindrical tube of inner and outer radii a and b carries a current i distributed uniformly over its cross section. Find the magnitude of the magnetic field at a point (a) just inside the tube (b) just outside the tube.
Answer» A long, cylindrical tube of inner and outer radii a and b carries a current i distributed uniformly over its cross section. Find the magnitude of the magnetic field at a point (a) just inside the tube (b) just outside the tube.

Discussion

20.	Q 11/200 Consider a thin conducting shell of radius rcarrying total charge q. A point charge 2q isplaced at point A, which is at distance 2r from thecentre C. If the shell is earthed, then how much chargewill flow to the earth?2r2q4q3qBetween 2q and 3q
Answer» Q 11/200 Consider a thin conducting shell of radius rcarrying total charge q. A point charge 2q isplaced at point A, which is at distance 2r from thecentre C. If the shell is earthed, then how much chargewill flow to the earth?2r2q4q3qBetween 2q and 3q

Discussion

21.	A box P and a coil Q are connected in series with an 10 VAC source of variable frequency. Box P contains a capacitance of 1 μF in series with a resistance of 32 Ω. Coil Q has a self inductance of 4.9 mH and a resistance of 68 Ω in series. The frequency is adjusted so that maximum current flows in P and Q.(i) The impedance of box P at this frequency is[1 Mark]
Answer» A box $P$ and a coil $Q$ are connected in series with an $10 V$ $AC$ source of variable frequency. Box $P$ contains a capacitance of $1 μ F$ in series with a resistance of $32 Ω$ . Coil $Q$ has a self inductance of $4.9 mH$ and a resistance of $68 Ω$ in series. The frequency is adjusted so that maximum current flows in $P and Q$ . $(i)$ The impedance of box $P$ at this frequency is $[$ 1 Mark $]$

Discussion

22.	A spherical solid ball of volune V is made of a material of density d1. It is falling through a liquid of density d2 (d2<d1) . assume that liquid applies viscous force on ball proportional to square of its speed as F=kv^2(k>0).terminal speed of ball is ?
Answer» A spherical solid ball of volune V is made of a material of density d1. It is falling through a liquid of density d2 (d2<d1) . assume that liquid applies viscous force on ball proportional to square of its speed as F=kv^2(k>0).terminal speed of ball is ?

Discussion

23.	The power radiated by a black body is P and it radiates maximum energy around the wavelength λ0. If the temperature of the black body is now changed so that it radiates maximum energy around wavelength 3λ04, the power radiated by it will increase by a factor of
Answer» The power radiated by a black body is P and it radiates maximum energy around the wavelength $λ_{0}$ . If the temperature of the black body is now changed so that it radiates maximum energy around wavelength $\frac{3 λ_{0}}{4}$ , the power radiated by it will increase by a factor of

Discussion

24.	A circular coil of 20 turns and 10 cm radius is placedin a uniform magnetic field of 0.10 T normal to theplane of the coil. If the current in the coil is 5 A,cross-sectional area is 10 m2 and coil is made upof copper wire having free electron density about1029 m, then the average force on each electron inthe coil due to magnetic field is(a) 2.5 x 10-25 N (b) 5 x 10-25 N(c) 4 x 10-25 N(d) 3 x 10-25 N
Answer» A circular coil of 20 turns and 10 cm radius is placedin a uniform magnetic field of 0.10 T normal to theplane of the coil. If the current in the coil is 5 A,cross-sectional area is 10 m2 and coil is made upof copper wire having free electron density about1029 m, then the average force on each electron inthe coil due to magnetic field is(a) 2.5 x 10-25 N (b) 5 x 10-25 N(c) 4 x 10-25 N(d) 3 x 10-25 N

Discussion

25.	The volume charge density as a function of distance X from one face inside a unit cube is varying as shown in the figure. If the total flux (in Wb) through the cube if P0=8.85×10−12 C/m3 is x4 then find the value of x (Give integer value)?
Answer» The volume charge density as a function of distance $X$ from one face inside a unit cube is varying as shown in the figure. If the total flux (in Wb) through the cube if $P_{0} = 8.85 \times 10^{- 12} {C/m}^{3}$ is $\frac{x}{4}$ then find the value of $x$ (Give integer value)?

Discussion

26.	For the arrangement shown in the figure, the switch is closed at t=0. The time after which the current becomes 2.5 μA is given by (take ln 2 = 0.69)
Answer» For the arrangement shown in the figure, the switch is closed at $t = 0$ . The time after which the current becomes $2.5 μ A$ is given by (take ln 2 = 0.69)

Discussion

27.	Two particles A and B are projected from the ground towards each other with speeds 10m/s and 5√2 m/s at angles 30° and 45° respectively with horizontal from two points separated by a distance of 15m . Will the collide?
Answer» Two particles A and B are projected from the ground towards each other with speeds 10m/s and 5√2 m/s at angles 30° and 45° respectively with horizontal from two points separated by a distance of 15m . Will the collide?

Discussion

28.	94.A projectile has a maximum range of 16 km.At the highest point of its motion,it explodes into two equal masses.One mass drops vertically downward the horizontal distance covered by the other mass from the time of explosion is?
Answer» 94.A projectile has a maximum range of 16 km.At the highest point of its motion,it explodes into two equal masses.One mass drops vertically downward the horizontal distance covered by the other mass from the time of explosion is?

Discussion

29.	If the wavelength of first member of Balmer series of hydrogen spectrum is 6564˙A, the wavelength of second member of Balmer series will be:
Answer» If the wavelength of first member of Balmer series of hydrogen spectrum is $6564 ˙ A$ , the wavelength of second member of Balmer series will be:

Discussion

30.	How can centre of mass of a body be outside.?
Answer» How can centre of mass of a body be outside.?

Discussion

31.	Light of wavelength 6000 ∘A is incident normally on a slit of width 24×10−5 cm. What is the angular position of second minimum from central maximum?
Answer» Light of wavelength $6000 \circ A$ is incident normally on a slit of width $24 \times 10^{- 5} cm$ . What is the angular position of second minimum from central maximum?

Discussion

32.	Air streams horizontally past an airplane. The speed of air over the top surface of the wings is 60 m/s and that under the bottom surface is 45 m/s. The density of air is 1.293 kg/m3. Then, the difference in pressure between the top and bottom surface of the wings is: (Consider airplane to be flying at a constant altitude)
Answer» Air streams horizontally past an airplane. The speed of air over the top surface of the wings is $60 m/s$ and that under the bottom surface is $45 m/s$ . The density of air is $1.293 {kg/m}^{3}$ . Then, the difference in pressure between the top and bottom surface of the wings is: (Consider airplane to be flying at a constant altitude)

Discussion

33.	57. Consider the situation shown in figure. Both the pulleys and the string are light and all the surfaces are frictionless. Find the acceleration of the mass M and tension in the string.
Answer» 57. Consider the situation shown in figure. Both the pulleys and the string are light and all the surfaces are frictionless. Find the acceleration of the mass M and tension in the string.

Discussion

34.	A fish look up through the water sees the outside world containing in a circular horizon. The radius of the circle is 12√7 cm. The depth of the fish from the water surface is[Refractive index of water is 43]
Answer» A fish look up through the water sees the outside world containing in a circular horizon. The radius of the circle is $12 \sqrt{7} cm$ . The depth of the fish from the water surface is [Refractive index of water is $\frac{4}{3}$ ]

Discussion

35.	63.A solid sphere of radius R made of materials of bulk modulus B surrounded by a piston of area A float on the surface of the liquid. Find the fractional decrease in the radius of the sphere when mass M is placed on the piston
Answer» 63.A solid sphere of radius R made of materials of bulk modulus B surrounded by a piston of area A float on the surface of the liquid. Find the fractional decrease in the radius of the sphere when mass M is placed on the piston

Discussion

36.	In the given figure, find the displacement of the block A in the x-axis in the time interval of 3 s (String is massless and inextensible)
Answer» In the given figure, find the displacement of the block $A$ in the $x$ -axis in the time interval of $3 s$ (String is massless and inextensible)

Discussion

37.	A turn table is rotatingin horizontalplane abouy its its own axis at an angular velocity 90rpm .while a person is on the turn table at its edge. If he gently walks to the center of table by which moment of inertia decreases by 25% than time period of rotationof turn table is
Answer» A turn table is rotatingin horizontalplane abouy its its own axis at an angular velocity 90rpm .while a person is on the turn table at its edge. If he gently walks to the center of table by which moment of inertia decreases by 25% than time period of rotationof turn table is

Discussion

38.	Find the potential drop across 4 μF capacitor and 6 Ω resistor as shown in the following circuit.
Answer» Find the potential drop across $4 μ F$ capacitor and $6 Ω$ resistor as shown in the following circuit.

Discussion

39.	38. Bond angle between ammonia and water
Answer» 38. Bond angle between ammonia and water

Discussion

40.	∫e2x [sec 2x + sec 2x.tan 2x]dx
Answer» $\int e^{2 x}$ [sec 2x + sec 2x.tan 2x]dx

Discussion

41.	A parallel-plate capacitor is being charged. The displacement current across an area in the region between the plates and parallel to it is equal to
Answer» A parallel-plate capacitor is being charged. The displacement current across an area in the region between the plates and parallel to it is equal to

Discussion

42.	a loaded vertical spring exceutes shm with a time period of 4s .the difference between the kinetic energy and potential energy of this system varies with a time period of
Answer» a loaded vertical spring exceutes shm with a time period of 4s .the difference between the kinetic energy and potential energy of this system varies with a time period of

Discussion

43.	A capacitor, an inductor and an electric bulb are connected in series to an AC supply of variable frequency. As the frequency of the supply is increased gradually, then the electric bulb is found to:
Answer» A capacitor, an inductor and an electric bulb are connected in series to an AC supply of variable frequency. As the frequency of the supply is increased gradually, then the electric bulb is found to:

Discussion

44.	The r.m.s. value of voltage and current are 200 V and 3 A respectively of an a.c. source. If the phase angle between the current and voltage is π6, then the power in the a.c. circuit is
Answer» The r.m.s. value of voltage and current are $200 V$ and $3 A$ respectively of an a.c. source. If the phase angle between the current and voltage is $\frac{π}{6}$ , then the power in the a.c. circuit is

Discussion

45.	An object is placed beyond the principal focus at a distance of 4 cm from it in front of a concave mirror on the principal axis. If the image is formed at a distance of 9 cm from the principal focus on the same side, then focal length of the mirror is
Answer» An object is placed beyond the principal focus at a distance of $4 cm$ from it in front of a concave mirror on the principal axis. If the image is formed at a distance of $9 cm$ from the principal focus on the same side, then focal length of the mirror is

Discussion

46.	A bar magnet has dimensions of 25 cm, 10 cm and 5 cm. If length of magnet is 25 cm and its pole strength is 200 × 10–3 Am, then intensity of magnetisation of magnet is
Answer» A bar magnet has dimensions of 25 cm, 10 cm and 5 cm. If length of magnet is 25 cm and its pole strength is 200 × 10–3 Am, then intensity of magnetisation of magnet is

Discussion

47.	Initially both the capacitors are having charges +Q, +2Q respectively as shown. Find heat loss in the resistance R after the switch is closed.प्रारम्भ में दोनों संधारित्रों पर आवेश दर्शाए अनुसार क्रमशः +Q, +2Q हैं। स्विच को बंद करने के बाद, प्रतिरोध R में ऊष्मा हानि ज्ञात कीजिए।
Answer» Initially both the capacitors are having charges +Q, +2Q respectively as shown. Find heat loss in the resistance R after the switch is closed. प्रारम्भ में दोनों संधारित्रों पर आवेश दर्शाए अनुसार क्रमशः +Q, +2Q हैं। स्विच को बंद करने के बाद, प्रतिरोध R में ऊष्मा हानि ज्ञात कीजिए।

Discussion

48.	If the velocity at a point is given as 3xi + 4 y j, then the vorticity at point (2,3) is units.0
Answer» If the velocity at a point is given as 3xi + 4 y j, then the vorticity at point (2,3) is units. 0

48.

If the velocity at a point is given as 3xi + 4 y j, then the vorticity at point (2,3) is units.0

Answer»

If the velocity at a point is given as 3xi + 4 y j, then the vorticity at point (2,3) is units.

0

Discussion

49.	Notice these expressions in the text. Infer their meanings from the context.
Answer» Notice these expressions in the text. Infer their meanings from the context.

Discussion

50.	50. Calculate wavelength of electron if is k.E is 5 kJ
Answer» 50. Calculate wavelength of electron if is k.E is 5 kJ

Discussion

Explore topic-wise InterviewSolutions in Current Affairs.

1 m3 water is brought inside the lake upto 200 metres depth from the surface of the lake. What will be change in the volume when the bulk modulus of elasticity of water is 22000 atmosphere? (density of water is 1×103 kg/m3, atmosphere pressure =105 N/m2 and g=10 m/s2)

The displacement time graph of two moving particles make angles of 30∘ and 45∘ with the X- axis is shown. The ratio of their velocities is:

The value of √rr1r2r32Rr(sinA+sinB+sinC) is equal to:

Gravitational field intensity due to a disc

If the units of force and length are doubled then the numerical value of energy will be?

Fringe width observed in the Young's double-slit experiment is β . If the frequency of the source is doubled, the fringe width will

The speed of a particle moving in a circle of radius r = 2 m varies with time t as v=t2 where t is in second and v in m/s. The net acceleration at t =2 s is

Find the maximum electric field due to a uniformly charged ring of charge Q and radius R along the axis of the ring [K=14πϵ0]

Two wires A and B of the same material, having radii in the ratio 1 : 2 and carry currents in the ratio 4 : 1. The ratio of drift speeds of electrons in A and B is:

A solid cylinder of mass M and radius R rolls down an inclined plane of height h. The angular velocity of the cylinder when it reaches the bottom of the plane will be

A stone of mass m is pushed down a frictionless hemispherical bowl of radius r from a point O. The stone just rises upto the half of other side of the bowl as shown in the figure, what is the initial speed of stone with which it was pushed?

Find the angular impulse applied to the particle in the 4 sec.

Two capacitors each having capacitance 3 μF and breakdown voltage 6 V are joined together in parallel connection. The breakdown voltage of the combination will be :

A particle of mass m is moving along the x-axis with initial velocity u^i. It collides elastically with a particle of mass 10m at rest and then moves with half its initial kinetic energy (see figure). If sinθ0=√nsinθ2, then value of n is

what will be the v_{e }from a planet having velocity 27 times that of earth and the same mean density as that of the earth.

What is value of potential inside a uniformly charged conducting sphere?

The given truth table is forInputOutputA ∣ BY0 ∣ 010 ∣ 111 ∣ 011 ∣ 10

A long, cylindrical tube of inner and outer radii a and b carries a current i distributed uniformly over its cross section. Find the magnitude of the magnetic field at a point (a) just inside the tube (b) just outside the tube.

Q 11/200 Consider a thin conducting shell of radius rcarrying total charge q. A point charge 2q isplaced at point A, which is at distance 2r from thecentre C. If the shell is earthed, then how much chargewill flow to the earth?2r2q4q3qBetween 2q and 3q

A spherical solid ball of volune V is made of a material of density d1. It is falling through a liquid of density d2 (d2&lt;d1) . assume that liquid applies viscous force on ball proportional to square of its speed as F=kv^2(k&gt;0).terminal speed of ball is ?

The power radiated by a black body is P and it radiates maximum energy around the wavelength λ0. If the temperature of the black body is now changed so that it radiates maximum energy around wavelength 3λ04, the power radiated by it will increase by a factor of

The volume charge density as a function of distance X from one face inside a unit cube is varying as shown in the figure. If the total flux (in Wb) through the cube if P0=8.85×10−12 C/m3 is x4 then find the value of x (Give integer value)?

For the arrangement shown in the figure, the switch is closed at t=0. The time after which the current becomes 2.5 μA is given by (take ln 2 = 0.69)

Two particles A and B are projected from the ground towards each other with speeds 10m/s and 5√2 m/s at angles 30° and 45° respectively with horizontal from two points separated by a distance of 15m . Will the collide?

94.A projectile has a maximum range of 16 km.At the highest point of its motion,it explodes into two equal masses.One mass drops vertically downward the horizontal distance covered by the other mass from the time of explosion is?

If the wavelength of first member of Balmer series of hydrogen spectrum is 6564˙A, the wavelength of second member of Balmer series will be:

How can centre of mass of a body be outside.?

Light of wavelength 6000 ∘A is incident normally on a slit of width 24×10−5 cm. What is the angular position of second minimum from central maximum?

57. Consider the situation shown in figure. Both the pulleys and the string are light and all the surfaces are frictionless. Find the acceleration of the mass M and tension in the string.

A fish look up through the water sees the outside world containing in a circular horizon. The radius of the circle is 12√7 cm. The depth of the fish from the water surface is[Refractive index of water is 43]

63.A solid sphere of radius R made of materials of bulk modulus B surrounded by a piston of area A float on the surface of the liquid. Find the fractional decrease in the radius of the sphere when mass M is placed on the piston

In the given figure, find the displacement of the block A in the x-axis in the time interval of 3 s (String is massless and inextensible)

A turn table is rotatingin horizontalplane abouy its its own axis at an angular velocity 90rpm .while a person is on the turn table at its edge. If he gently walks to the center of table by which moment of inertia decreases by 25% than time period of rotationof turn table is

Find the potential drop across 4 μF capacitor and 6 Ω resistor as shown in the following circuit.

38. Bond angle between ammonia and water

∫e2x [sec 2x + sec 2x.tan 2x]dx

A parallel-plate capacitor is being charged. The displacement current across an area in the region between the plates and parallel to it is equal to

a loaded vertical spring exceutes shm with a time period of 4s .the difference between the kinetic energy and potential energy of this system varies with a time period of

A capacitor, an inductor and an electric bulb are connected in series to an AC supply of variable frequency. As the frequency of the supply is increased gradually, then the electric bulb is found to:

The r.m.s. value of voltage and current are 200 V and 3 A respectively of an a.c. source. If the phase angle between the current and voltage is π6, then the power in the a.c. circuit is

An object is placed beyond the principal focus at a distance of 4 cm from it in front of a concave mirror on the principal axis. If the image is formed at a distance of 9 cm from the principal focus on the same side, then focal length of the mirror is

A bar magnet has dimensions of 25 cm, 10 cm and 5 cm. If length of magnet is 25 cm and its pole strength is 200 × 10–3 Am, then intensity of magnetisation of magnet is

If the velocity at a point is given as 3xi + 4 y j, then the vorticity at point (2,3) is units.0

Notice these expressions in the text. Infer their meanings from the context.

50. Calculate wavelength of electron if is k.E is 5 kJ

A spherical solid ball of volune V is made of a material of density d1. It is falling through a liquid of density d2 (d2<d1) . assume that liquid applies viscous force on ball proportional to square of its speed as F=kv^2(k>0).terminal speed of ball is ?