3731 + Interview Questions in Physics Page 57 InterviewSolution

2801.	The explosion of the atomic bomb takes place due to
Answer» The explosion of the atomic bomb takes place due to

Discussion

2802.	Two rods A and B of different materials are welded together as shown in the figure. If their thermal conductivities are k1 and k2, the thermal conductivity of the composite rod will be
Answer» Two rods A and B of different materials are welded together as shown in the figure. If their thermal conductivities are $k_{1}$ and $k_{2}$ , the thermal conductivity of the composite rod will be

Discussion

2803.	A satellite S is moving in an elliptical orbit around the earth. The mass of the satellite is very small compared to the mass of the earth :
Answer» A satellite S is moving in an elliptical orbit around the earth. The mass of the satellite is very small compared to the mass of the earth :

Discussion

2804.	A cylindrical cavity of diameter a exists inside a cylinder of diameter 2a as shown in the figure. Both the cylinder and the cavity are infinitely long. A uniform current density J flows along the length. If the magnitude of the magnetic field at the point P is given by N12μ0aJ, then the value of N is
Answer» A cylindrical cavity of diameter $a$ exists inside a cylinder of diameter $2 a$ as shown in the figure. Both the cylinder and the cavity are infinitely long. A uniform current density $J$ flows along the length. If the magnitude of the magnetic field at the point $P$ is given by $\frac{N}{12} μ_{0} a J$ , then the value of $N$ is

Discussion

2805.	If electronic charge e, electron mass m, speed of light in vaccum c and Plank's constant h are taken as fundamental quantities, the permeability of vaccum μ0 can be expressed in units ofHint: [h]=[ML2T−1],[μ0]=[MLT−2A−2]
Answer» If electronic charge $e$ , electron mass $m$ , speed of light in vaccum $c$ and Plank's constant $h$ are taken as fundamental quantities, the permeability of vaccum $μ_{0}$ can be expressed in units of Hint: $[h] = [M L^{2} T^{- 1}], [μ_{0}] = [M L T^{- 2} A^{- 2}]$

Discussion

2806.	The range of a projectile for a given initial velocity is maximum when the angle of projection is 45∘. The range will be minimum, if the angle of projection is
Answer» The range of a projectile for a given initial velocity is maximum when the angle of projection is $45^{\circ}$ . The range will be minimum, if the angle of projection is

Discussion

2807.	Two blocks of masses 1 kg and 2 kg are connected by a metal wire going over a smooth pulley as shown in figure. The breaking stress of the metal is 2×109 N m−2. What should be the minimum radius of the wire used if it is not to break? Take g = 10 m s−2.
Answer» Two blocks of masses 1 kg and 2 kg are connected by a metal wire going over a smooth pulley as shown in figure. The breaking stress of the metal is $2 \times 10^{9} N m^{- 2}$ . What should be the minimum radius of the wire used if it is not to break? Take $g = 10 m s^{- 2}$ .

2807.

Two blocks of masses 1 kg and 2 kg are connected by a metal wire going over a smooth pulley as shown in figure. The breaking stress of the metal is 2×109 N m−2. What should be the minimum radius of the wire used if it is not to break? Take g = 10 m s−2.

Answer»

Two blocks of masses 1 kg and 2 kg are connected by a metal wire going over a smooth pulley as shown in figure. The breaking stress of the metal is $2 \times 10^{9} N m^{- 2}$ . What should be the minimum radius of the wire used if it is not to break? Take $g = 10 m s^{- 2}$ .

Discussion

2808.	Two waves of equal frequencies moving in the same direction have their amplitudes in the ratio 7:5. They are superimposed on each other. Find the ratio of maximum to minimum intensity of the resultant wave.
Answer» Two waves of equal frequencies moving in the same direction have their amplitudes in the ratio $7 : 5$ . They are superimposed on each other. Find the ratio of maximum to minimum intensity of the resultant wave.

Discussion

2809.	A harmonic wave propagates in a medium. Find the average energy density of the wave, if at any point, the energy density becomes equal to W0 at an instant t=t0+T/6, where t0 is the instant when amplitude is maximum at this location and T is the time period of oscillation.
Answer» A harmonic wave propagates in a medium. Find the average energy density of the wave, if at any point, the energy density becomes equal to $W_{0}$ at an instant $t = t_{0} + T / 6$ , where $t_{0}$ is the instant when amplitude is maximum at this location and $T$ is the time period of oscillation.

Discussion

2810.	The destiny of parallel rays in a spherical mirror (within paraxial approximation) is :
Answer» The destiny of parallel rays in a spherical mirror (within paraxial approximation) is :

Discussion

2811.	A mass M is lowered with the help of a string by a distance h at a constant acceleration g2. The work done by string will be
Answer» A mass M is lowered with the help of a string by a distance h at a constant acceleration $\frac{g}{2}$ . The work done by string will be

Discussion

2812.	The linear density of a rod of length ‘L’ at a distance ‘x’ from one end is given by calculate the mass of rod, given λ0 is the density of the rod at x = 0.
Answer» The linear density of a rod of length ‘L’ at a distance ‘x’ from one end is given by calculate the mass of rod, given $λ_{0}$ is the density of the rod at x = 0.

Discussion

2813.	Two wires are made of the same material and have the same volume. However, wire 1 has cross - sectional area A and wire-2 has cross - sectional area 3A. If the length of wire 1 increases by Δx on applying force F, how much force is needed to stretch wire 2 by the same amount?
Answer» Two wires are made of the same material and have the same volume. However, wire $1$ has cross - sectional area $A$ and wire- $2$ has cross - sectional area $3 A$ . If the length of wire $1$ increases by $Δ x$ on applying force $F$ , how much force is needed to stretch wire $2$ by the same amount?

Discussion

2814.	A frictionless wire AB is fixed on a circular frame of radius R. A very small spherical ball slips on this wire. The time taken by this ball to slip from A to B is
Answer» A frictionless wire AB is fixed on a circular frame of radius R. A very small spherical ball slips on this wire. The time taken by this ball to slip from A to B is

2814.

A frictionless wire AB is fixed on a circular frame of radius R. A very small spherical ball slips on this wire. The time taken by this ball to slip from A to B is

Answer»

A frictionless wire AB is fixed on a circular frame of radius R. A very small spherical ball slips on this wire. The time taken by this ball to slip from A to B is

Discussion

2815.	Block A & B of mass m each are connected with spring of constant k, both blocks lie on frictionless ground and are imparted horizontal velocity v as shown. Initially spring is unstretched, find the maximum extension of the spring.
Answer» Block $A$ & $B$ of mass $m$ each are connected with spring of constant $k$ , both blocks lie on frictionless ground and are imparted horizontal velocity $v$ as shown. Initially spring is unstretched, find the maximum extension of the spring.

Discussion

2816.	A car of mass 800 kg moves on a horizontal circular track of radius 40 m. If the coefficient of static friction (μs) is 0.5, then the maximum velocity with which the car can move will be
Answer» A car of mass $800 kg$ moves on a horizontal circular track of radius $40 m$ . If the coefficient of static friction ( $μ_{s}$ ) is $0.5$ , then the maximum velocity with which the car can move will be

Discussion

2817.	If surface area of a cube is changing at a rate of 18 m2/s , find the rate at which length of the body diagonal changes, at a moment when side length is 3 m.
Answer» If surface area of a cube is changing at a rate of $18 m^{2} / s$ , find the rate at which length of the body diagonal changes, at a moment when side length is $3 m$ .

Discussion

2818.	Length of a string of density ρ and Young’s modulus Y under tension is increased by 1n times of its original length. If the velocity of transverse and longitudinal vibrations of the string is same, find the value of such velocity.
Answer» Length of a string of density ρ and Young’s modulus Y under tension is increased by $\frac{1}{n}$ times of its original length. If the velocity of transverse and longitudinal vibrations of the string is same, find the value of such velocity.

Discussion

2819.	An aircraft executes a vertical turn of radius R=500 m with a constant velocity v=360 km/h. The normal reaction on the pilot of mass m=70 kg at the lower, upper and middle points of the loop will respectively be :-
Answer» An aircraft executes a vertical turn of radius $R = 500 m$ with a constant velocity $v = 360 km/h$ . The normal reaction on the pilot of mass $m = 70 kg$ at the lower, upper and middle points of the loop will respectively be :-

Discussion

2820.	In the figure shown, find the acceleration (in m/s2) of the 2 kg body and the tension (in N) in the string. (String is massless and inextensible)
Answer» In the figure shown, find the acceleration (in $m / s^{2}$ ) of the $2 k g$ body and the tension (in $N$ ) in the string. (String is massless and inextensible)

Discussion

2821.	If the kinetic energy of a free electron doubles, its de-Broglie wave length changes by the factor of
Answer» If the kinetic energy of a free electron doubles, its de-Broglie wave length changes by the factor of

Discussion

2822.	The velocity of a particle is v=v0+ct+gt2. If its position is x=0 at t=0, then its displacement at time (t=2 sec) is
Answer» The velocity of a particle is $v = v_{0} + c t + g t^{2}$ . If its position is $x = 0$ at $t = 0$ , then its displacement at time $(t = 2 sec)$ is

Discussion

2823.	Average total energy density for a transverse wave is 16 J/m. The average kinetic energy density for the corresponding wave will be
Answer» Average total energy density for a transverse wave is $16 J/m$ . The average kinetic energy density for the corresponding wave will be

Discussion

2824.	Which of these can most likely be 3^i+6^j
Answer» Which of these can most likely be $3^i + 6^j$

Discussion

2825.	Identify the correct order of temperature as indicated in given diagram for same gas.
Answer» Identify the correct order of temperature as indicated in given diagram for same gas.

Discussion

2826.	Find velocity of ring B (VB) at an instant as shown. The string is taut and inextensible:
Answer» Find velocity of ring B ( $V_{B}$ ) at an instant as shown. The string is taut and inextensible:

2826.

Find velocity of ring B (VB) at an instant as shown. The string is taut and inextensible:

Answer»

Find velocity of ring B ( $V_{B}$ ) at an instant as shown. The string is taut and inextensible:

Discussion

2827.	A heavy particle is projected with a velocity at an angle with the horizontal into a uniform gravitational field. The slope of the trajectory of the particle varies not according to which of the following curves?
Answer» A heavy particle is projected with a velocity at an angle with the horizontal into a uniform gravitational field. The slope of the trajectory of the particle varies not according to which of the following curves?

Discussion

2828.	A transverse wave y=5sin(3t−x), where y,x,t are in SI units, is propagating on a stretched string having density ρ=1 kg/m3. Find the intensity of propagating wave.
Answer» A transverse wave $y = 5 sin (3 t - x)$ , where $y, x, t$ are in SI units, is propagating on a stretched string having density $ρ = 1 {kg/m}^{3}$ . Find the intensity of propagating wave.

Discussion

2829.	Two smooth cylindrical bars weighing W each, lie next to each other in contact. A similar third bar is placed over the two bars as shown in figure. Neglecting friction, the minimum horizontal force on each lower bar necessary to keep them together is
Answer» Two smooth cylindrical bars weighing $W$ each, lie next to each other in contact. A similar third bar is placed over the two bars as shown in figure. Neglecting friction, the minimum horizontal force on each lower bar necessary to keep them together is

Discussion

2830.	Two roads one along y-axis and another along a direction at angle θ with x-axis as shown in figure. Two cars 'A' and car 'B' are moving along the roads. Consider the situation of the diagram. Draw the direction of car 'B' as seen from car 'A'.
Answer» Two roads one along y-axis and another along a direction at angle $θ$ with x-axis as shown in figure. Two cars 'A' and car 'B' are moving along the roads. Consider the situation of the diagram. Draw the direction of car 'B' as seen from car 'A'.

2830.

Two roads one along y-axis and another along a direction at angle θ with x-axis as shown in figure. Two cars 'A' and car 'B' are moving along the roads. Consider the situation of the diagram. Draw the direction of car 'B' as seen from car 'A'.

Answer»

Two roads one along y-axis and another along a direction at angle $θ$ with x-axis as shown in figure. Two cars 'A' and car 'B' are moving along the roads. Consider the situation of the diagram. Draw the direction of car 'B' as seen from car 'A'.

Discussion

2831.	Figure shows three temperature scales with the freezing and boiling point of water indicated. A change of 25∘P,25∘Q,25∘R are denoted by X1,X2,X3 respectively. Which of the following is correct?
Answer» Figure shows three temperature scales with the freezing and boiling point of water indicated. A change of $25^{\circ} P, 25^{\circ} Q, 25^{\circ} R$ are denoted by $X_{1}, X_{2}, X_{3}$ respectively. Which of the following is correct?

Discussion

2832.	Two long parallel wires carrying currents 2.5 A and "I" A in the same direction (directed in the o plane) are held at P and Q respectively as shown. The points P and Q are located at a distance of 5 m and 2 m respectively from a collinear point R. An electron moving with a velocity of 4×105 ms−1 along the positive x-axis experiences a force of magnitude 3.2×10−20 N at the point R. The value of I is
Answer» Two long parallel wires carrying currents 2.5 A and "I" A in the same direction (directed in the o plane) are held at P and Q respectively as shown. The points P and Q are located at a distance of 5 m and 2 m respectively from a collinear point R. An electron moving with a velocity of $4 \times 10^{5} m s^{- 1}$ along the positive x-axis experiences a force of magnitude $3.2 \times 10^{- 20} N$ at the point R. The value of I is

Discussion

2833.	Which one of the following represents forward bias diode?
Answer» Which one of the following represents forward bias diode?

Discussion

2834.	The threshold wavelength for photoelectric effect of a metal is 6500 ∘A. The work function of the metal is approximately
Answer» The threshold wavelength for photoelectric effect of a metal is $6500 \circ A$ . The work function of the metal is approximately

Discussion

2835.	For a cell, the terminal potential difference is 2.2 V when the circuit is open and reduces to 1.8 V, when the cell is connected across a resistance, R=5Ω. The internal resistance of the cell is
Answer» For a cell, the terminal potential difference is 2.2 V when the circuit is open and reduces to 1.8 V, when the cell is connected across a resistance, $R = 5 Ω$ . The internal resistance of the cell is

Discussion

2836.	What is the angle between the following vectors?→A=3^i−2^j+^k→B=2^i+6^j−6^k
Answer» What is the angle between the following vectors? $\to A = 3^i - 2^j +^k$ $\to B = 2^i + 6^j - 6^k$

2836.

What is the angle between the following vectors?→A=3^i−2^j+^k→B=2^i+6^j−6^k

Answer»

What is the angle between the following vectors?

$\to A = 3^i - 2^j +^k$

$\to B = 2^i + 6^j - 6^k$

Discussion

2837.	A man has a weight 105 N on a weighing machine kept near the north pole of the earth. What will be the reduction in the weight of the man if he moves to the equator? Take g=9.8 m/s2, radius of earth (R)=6400 km, angular speed of the earth ω=7.27×10−5 rad/s.
Answer» A man has a weight $105 N$ on a weighing machine kept near the north pole of the earth. What will be the reduction in the weight of the man if he moves to the equator? Take $g = 9.8 {m/s}^{2}$ , radius of earth ( $R) = 6400 km$ , angular speed of the earth $ω = 7.27 \times 10^{- 5} rad/s$ .

Discussion

2838.	If a particle revolves in a circle of radius R, with time period T. The average speed and average velocity during two complete revolutions of the particle will respectively be
Answer» If a particle revolves in a circle of radius $R$ , with time period $T$ . The average speed and average velocity during two complete revolutions of the particle will respectively be

Discussion

2839.	Resistance of each branch in the given figure is 1Ω. Equivalent resistance of circuit between point A and B is :
Answer» Resistance of each branch in the given figure is $1 Ω$ . Equivalent resistance of circuit between point A and B is :

Discussion

2840.	Figure shows a smooth curved track terminating in a smooth horizontal part. A spring of spring constant 400 N/m is attached at one end to a wedge fixed rigidly with the horizontal part. A 40 g mass is released from rest at a height of 4.9 m on the curved track. Find the maximum compression of the spring. (g = 9.8 m/s2)
Answer» Figure shows a smooth curved track terminating in a smooth horizontal part. A spring of spring constant 400 N/m is attached at one end to a wedge fixed rigidly with the horizontal part. A 40 g mass is released from rest at a height of 4.9 m on the curved track. Find the maximum compression of the spring. (g = 9.8 m/ $s^{2}$ )

2840.

Figure shows a smooth curved track terminating in a smooth horizontal part. A spring of spring constant 400 N/m is attached at one end to a wedge fixed rigidly with the horizontal part. A 40 g mass is released from rest at a height of 4.9 m on the curved track. Find the maximum compression of the spring. (g = 9.8 m/s2)

Answer»

Figure shows a smooth curved track terminating in a smooth horizontal part. A spring of spring constant 400 N/m is attached at one end to a wedge fixed rigidly with the horizontal part. A 40 g mass is released from rest at a height of 4.9 m on the curved track. Find the maximum compression of the spring. (g = 9.8 m/ $s^{2}$ )

Discussion

2841.	In a beyblade game, the beyblade has an initial angular speed of 180 rpm. It slows down and eventually comes to rest in a time of 5 minutes. The average angular acceleration of the beyblade is
Answer» In a beyblade game, the beyblade has an initial angular speed of $180 rpm$ . It slows down and eventually comes to rest in a time of 5 minutes. The average angular acceleration of the beyblade is

Discussion

2842.	Daylight (photopic) vision and colour vision are functions of
Answer» Daylight (photopic) vision and colour vision are functions of

Discussion

2843.	Let 'l' be the moment of inertia of an uniform square plate about an axis AB that passes through its centre and is parallel to two of its sides. CD is a line in the plane of the plate that passes through the centre of the plate and makes an angle θ with AB. The moment of inertia of the plate about the axis CD is then equal to
Answer» Let 'l' be the moment of inertia of an uniform square plate about an axis AB that passes through its centre and is parallel to two of its sides. CD is a line in the plane of the plate that passes through the centre of the plate and makes an angle $θ$ with AB. The moment of inertia of the plate about the axis CD is then equal to

Discussion

2844.	What is the radius of curvature of a convex mirror if the focal length is 60 cm?
Answer» What is the radius of curvature of a convex mirror if the focal length is $60 cm$ ?

Discussion

2845.	The figure shows the velocity and acceleration of a point like body at the initial moment of its motion. The acceleration vector of the body remains constant. The minimum radius of curvature of trajectory of the body is (in m upto two decimals.)
Answer» The figure shows the velocity and acceleration of a point like body at the initial moment of its motion. The acceleration vector of the body remains constant. The minimum radius of curvature of trajectory of the body is (in $m$ upto two decimals.)

Discussion

2846.	What if I wanted the displacement and distance of a body between times t = 0 and time t = 5 for V(t)=4−t2
Answer» What if I wanted the displacement and distance of a body between times t = 0 and time t = 5 for $V (t) = 4 - t^{2}$

Discussion

2847.	The masses and radii of the earth and moon areM1, R1 and M2, R2 respectively. Their centres are a distance d apart. The minimum speed with which a particle of mass m should be projected from a point midway between the two centres so as to escape to infinity is given by
Answer» The masses and radii of the earth and moon are $M_{1}$ , $R_{1}$ and $M_{2}$ , $R_{2}$ respectively. Their centres are a distance d apart. The minimum speed with which a particle of mass m should be projected from a point midway between the two centres so as to escape to infinity is given by

Discussion

2848.	The relationship between Young's modulus Y, Bulk modulus K and modulus of rigidity η is
Answer» The relationship between Young's modulus Y, Bulk modulus K and modulus of rigidity $η$ is

Discussion

2849.	A tuning fork is used to produce resonance in a glass tube. The length of the air column in this tube can be adjusted by a variable piston. At room temperture of 27oC, two successive resonances are produced at 20 cm and 73 cm of column length. If the frequency of the tuning fork is 320 Hz, the velocity of sound in air at 27oC is approximately
Answer» A tuning fork is used to produce resonance in a glass tube. The length of the air column in this tube can be adjusted by a variable piston. At room temperture of $27^{o} C$ , two successive resonances are produced at $20 c m$ and $73 c m$ of column length. If the frequency of the tuning fork is $320 H z$ , the velocity of sound in air at $27^{o} C$ is approximately

Discussion

2850.	Mass of spacecraft varies with time as m=5000 e−t kg. Find the rate of fuel ejection after 5 s. (Take e=2.718)
Answer» Mass of spacecraft varies with time as $m = 5000 e^{- t} kg$ . Find the rate of fuel ejection after $5 s$ . (Take $e = 2.718$ )

Discussion

Explore topic-wise InterviewSolutions in .

The explosion of the atomic bomb takes place due to

Two rods A and B of different materials are welded together as shown in the figure. If their thermal conductivities are k1 and k2, the thermal conductivity of the composite rod will be

A satellite S is moving in an elliptical orbit around the earth. The mass of the satellite is very small compared to the mass of the earth :

If electronic charge e, electron mass m, speed of light in vaccum c and Plank's constant h are taken as fundamental quantities, the permeability of vaccum μ0 can be expressed in units ofHint: [h]=[ML2T−1],[μ0]=[MLT−2A−2]

The range of a projectile for a given initial velocity is maximum when the angle of projection is 45∘. The range will be minimum, if the angle of projection is

Two blocks of masses 1 kg and 2 kg are connected by a metal wire going over a smooth pulley as shown in figure. The breaking stress of the metal is 2×109 N m−2. What should be the minimum radius of the wire used if it is not to break? Take g = 10 m s−2.

Two waves of equal frequencies moving in the same direction have their amplitudes in the ratio 7:5. They are superimposed on each other. Find the ratio of maximum to minimum intensity of the resultant wave.

A harmonic wave propagates in a medium. Find the average energy density of the wave, if at any point, the energy density becomes equal to W0 at an instant t=t0+T/6, where t0 is the instant when amplitude is maximum at this location and T is the time period of oscillation.

The destiny of parallel rays in a spherical mirror (within paraxial approximation) is :

A mass M is lowered with the help of a string by a distance h at a constant acceleration g2. The work done by string will be

The linear density of a rod of length ‘L’ at a distance ‘x’ from one end is given by calculate the mass of rod, given λ0 is the density of the rod at x = 0.

Two wires are made of the same material and have the same volume. However, wire 1 has cross - sectional area A and wire-2 has cross - sectional area 3A. If the length of wire 1 increases by Δx on applying force F, how much force is needed to stretch wire 2 by the same amount?

A frictionless wire AB is fixed on a circular frame of radius R. A very small spherical ball slips on this wire. The time taken by this ball to slip from A to B is

Block A &amp; B of mass m each are connected with spring of constant k, both blocks lie on frictionless ground and are imparted horizontal velocity v as shown. Initially spring is unstretched, find the maximum extension of the spring.

A car of mass 800 kg moves on a horizontal circular track of radius 40 m. If the coefficient of static friction (μs) is 0.5, then the maximum velocity with which the car can move will be

If surface area of a cube is changing at a rate of 18 m2/s , find the rate at which length of the body diagonal changes, at a moment when side length is 3 m.

Length of a string of density ρ and Young’s modulus Y under tension is increased by 1n times of its original length. If the velocity of transverse and longitudinal vibrations of the string is same, find the value of such velocity.

An aircraft executes a vertical turn of radius R=500 m with a constant velocity v=360 km/h. The normal reaction on the pilot of mass m=70 kg at the lower, upper and middle points of the loop will respectively be :-

In the figure shown, find the acceleration (in m/s2) of the 2 kg body and the tension (in N) in the string. (String is massless and inextensible)

If the kinetic energy of a free electron doubles, its de-Broglie wave length changes by the factor of

The velocity of a particle is v=v0+ct+gt2. If its position is x=0 at t=0, then its displacement at time (t=2 sec) is

Average total energy density for a transverse wave is 16 J/m. The average kinetic energy density for the corresponding wave will be

Which of these can most likely be 3^i+6^j

Identify the correct order of temperature as indicated in given diagram for same gas.

Find velocity of ring B (VB) at an instant as shown. The string is taut and inextensible:

A heavy particle is projected with a velocity at an angle with the horizontal into a uniform gravitational field. The slope of the trajectory of the particle varies not according to which of the following curves?

A transverse wave y=5sin(3t−x), where y,x,t are in SI units, is propagating on a stretched string having density ρ=1 kg/m3. Find the intensity of propagating wave.

Two smooth cylindrical bars weighing W each, lie next to each other in contact. A similar third bar is placed over the two bars as shown in figure. Neglecting friction, the minimum horizontal force on each lower bar necessary to keep them together is

Two roads one along y-axis and another along a direction at angle θ with x-axis as shown in figure. Two cars 'A' and car 'B' are moving along the roads. Consider the situation of the diagram. Draw the direction of car 'B' as seen from car 'A'.

Figure shows three temperature scales with the freezing and boiling point of water indicated. A change of 25∘P,25∘Q,25∘R are denoted by X1,X2,X3 respectively. Which of the following is correct?

Which one of the following represents forward bias diode?

The threshold wavelength for photoelectric effect of a metal is 6500 ∘A. The work function of the metal is approximately

For a cell, the terminal potential difference is 2.2 V when the circuit is open and reduces to 1.8 V, when the cell is connected across a resistance, R=5Ω. The internal resistance of the cell is

What is the angle between the following vectors?→A=3^i−2^j+^k→B=2^i+6^j−6^k

A man has a weight 105 N on a weighing machine kept near the north pole of the earth. What will be the reduction in the weight of the man if he moves to the equator? Take g=9.8 m/s2, radius of earth (R)=6400 km, angular speed of the earth ω=7.27×10−5 rad/s.

If a particle revolves in a circle of radius R, with time period T. The average speed and average velocity during two complete revolutions of the particle will respectively be

Resistance of each branch in the given figure is 1Ω. Equivalent resistance of circuit between point A and B is :

In a beyblade game, the beyblade has an initial angular speed of 180 rpm. It slows down and eventually comes to rest in a time of 5 minutes. The average angular acceleration of the beyblade is

Daylight (photopic) vision and colour vision are functions of

What is the radius of curvature of a convex mirror if the focal length is 60 cm?

The figure shows the velocity and acceleration of a point like body at the initial moment of its motion. The acceleration vector of the body remains constant. The minimum radius of curvature of trajectory of the body is (in m upto two decimals.)

What if I wanted the displacement and distance of a body between times t = 0 and time t = 5 for V(t)=4−t2

The masses and radii of the earth and moon areM1, R1 and M2, R2 respectively. Their centres are a distance d apart. The minimum speed with which a particle of mass m should be projected from a point midway between the two centres so as to escape to infinity is given by

The relationship between Young's modulus Y, Bulk modulus K and modulus of rigidity η is

Mass of spacecraft varies with time as m=5000 e−t kg. Find the rate of fuel ejection after 5 s. (Take e=2.718)

Block A & B of mass m each are connected with spring of constant k, both blocks lie on frictionless ground and are imparted horizontal velocity v as shown. Initially spring is unstretched, find the maximum extension of the spring.