50278 + Interview Questions in Physics

1.	A stone is dropped into a well in which the level of water is h below the top of well. If V is the velocity of sound, the time T after which the splash is heard is given by
Answer» A stone is dropped into a well in which the level of water is $h$ below the top of well. If $V$ is the velocity of sound, the time $T$ after which the splash is heard is given by

Discussion

2.	Two coherent sources, emitting waves of wavelength λ, are placed at a separation of 3λ. A detector is moving around them on a large circle. The number of minima detected by it in one complete rotation is
Answer» Two coherent sources, emitting waves of wavelength $λ$ , are placed at a separation of $3 λ$ . A detector is moving around them on a large circle. The number of minima detected by it in one complete rotation is

Discussion

3.	Two bars of same length and same cross-sectional area but of different thermal conductivities K1 and K2 are joined end to end as shown in the figure. One end of the compound bar is at temperature T1 and the opposite end at temperature T2 (where T1>T2).The temperature of the junction is
Answer» Two bars of same length and same cross-sectional area but of different thermal conductivities $K_{1}$ and $K_{2}$ are joined end to end as shown in the figure. One end of the compound bar is at temperature $T_{1}$ and the opposite end at temperature $T_{2}$ (where $T_{1} > T_{2}$ ).The temperature of the junction is

Discussion

4.	The x - y plane is the boundary between two transparent media. Medium -1 with z > 0 has refractive index √2 and medium - 2 with z < 0 has a refractive index √3. A ray of light in medium -1 given by the vector →A=6√3i+8√3j−10^k is incident on the plane of separation. If the unit vector in the direction of refracted ray in medium - 2 is 15(a^i+b^j−5√2^k), then find the value of ab.___
Answer» The x - y plane is the boundary between two transparent media. Medium -1 with z > 0 has refractive index $\sqrt{2}$ and medium - 2 with z < 0 has a refractive index $\sqrt{3}$ . A ray of light in medium -1 given by the vector $\to A = 6 \sqrt{3 i} + 8 \sqrt{3 j} - 10^k$ is incident on the plane of separation. If the unit vector in the direction of refracted ray in medium - 2 is $\frac{1}{5} (a^i + b^j - \frac{5}{\sqrt{2}^k})$ , then find the value of ab.___

Discussion

5.	A motor drives a body along a straight line with a constant force. The power P developed by the motor must vary with time t as
Answer» A motor drives a body along a straight line with a constant force. The power P developed by the motor must vary with time t as

Discussion

6.	An object moves on a circular path; such that, its distance covered is given by the function S=2t2. The ratio of magnitudes of its accelerations at times t1=1 sec and t2=2 sec is 1 : 2. The radius of the circle is (Write until two digits after the decimal point)
Answer» An object moves on a circular path; such that, its distance covered is given by the function $S = 2 t^{2}$ . The ratio of magnitudes of its accelerations at times $t_{1} = 1 s e c$ and $t_{2} = 2$ sec is 1 : 2. The radius of the circle is (Write until two digits after the decimal point)

Discussion

7.	A small steel ball of radius r is allowed to fall under gravity through a column of a viscous liquid of coefficient of viscosity η. After some time the velocity of the ball attains a constant value known as terminal velocity vT. The terminal velocity depends on (i) the mass of the ball m, (ii) η, (iii) r, and (iv) acceleration due to gravity g. Which of the following relations is dimensionally correct?
Answer» A small steel ball of radius $r$ is allowed to fall under gravity through a column of a viscous liquid of coefficient of viscosity $η$ . After some time the velocity of the ball attains a constant value known as terminal velocity $v_{T} .$ The terminal velocity depends on $(i)$ the mass of the ball $m$ , $(i i)$ $η$ , $(i i i)$ $r$ , and $(i v)$ acceleration due to gravity $g$ . Which of the following relations is dimensionally correct?

Discussion

8.	The Kα X- rays arising from a cobalt (Z=27) target have a wavelength of 179 pm. The Kα X rays arising from a nickle target (Z=28) is
Answer» The $K_{α}$ X- rays arising from a cobalt ( $Z = 27$ ) target have a wavelength of 179 $p m$ . The $K_{α}$ X rays arising from a nickle target (Z=28) is

Discussion

9.	Two audio speakers are kept some distance apart and are driven by the same amplifier system. A person is sitting at a place 6.0 m from one of the speakers and 6.4 m from the other. If the sound signal is continuously varied from 500 Hz to 5000 Hz, what are the frequencies for which there is a destructive interference at the place of the listener? Speed of sound in air = 320 ms.
Answer» Two audio speakers are kept some distance apart and are driven by the same amplifier system. A person is sitting at a place 6.0 m from one of the speakers and 6.4 m from the other. If the sound signal is continuously varied from 500 Hz to 5000 Hz, what are the frequencies for which there is a destructive interference at the place of the listener? Speed of sound in air = $320 \frac{m}{s}$ .

Discussion

10.	A civil engineer wishes to redesign the curved roadway in such a way that a car will not have to rely on friction to round the curve without skidding. In other words, a car moving at the designated speed can negotiate the curve even when the road is covered with ice. Such a ramp is usually banked, which means that the roadway is tilted toward the inside of the curve. Suppose the designated speed for the ramp is to be 10.0 m/s and the radius of the curve is 20.0 m. At what angle should the curve be banked?
Answer» A civil engineer wishes to redesign the curved roadway in such a way that a car will not have to rely on friction to round the curve without skidding. In other words, a car moving at the designated speed can negotiate the curve even when the road is covered with ice. Such a ramp is usually banked, which means that the roadway is tilted toward the inside of the curve. Suppose the designated speed for the ramp is to be 10.0 m/s and the radius of the curve is 20.0 m. At what angle should the curve be banked?

Discussion

11.	A massless rod of length 1 m is suspended by two vertical strings of same length. Area of cross-section of left string is 'A' and its young's modulus is 32Y, whereas area of cross-section of right string is 2A and its young's modulus is Y. A block of mass 'm' is placed at 'x' cm from left string. If strains in both strings is same, then 'x' is . (Answer upto two digits after the decimal point)
Answer» A massless rod of length 1 m is suspended by two vertical strings of same length. Area of cross-section of left string is 'A' and its young's modulus is $\frac{3}{2} Y$ , whereas area of cross-section of right string is 2A and its young's modulus is Y. A block of mass 'm' is placed at 'x' cm from left string. If strains in both strings is same, then 'x' is . (Answer upto two digits after the decimal point)

Discussion

12.	Using differentials, find the approximate value of the following up to 3 places of decimal. (82)14
Answer» Using differentials, find the approximate value of the following up to 3 places of decimal. $(82)^{\frac{1}{4}}$

Discussion

13.	A battery is charged at a potential of 15 V for 8 h when the current flowing is 10 A. The battery on discharge supplies a current of 5 A for 15 h. The mean terminal voltage during discharge is 14 V. The watt-hour efficiency of the battery is
Answer» A battery is charged at a potential of $15 V$ for $8 h$ when the current flowing is $10 A$ . The battery on discharge supplies a current of $5 A$ for $15 h$ . The mean terminal voltage during discharge is $14 V$ . The watt-hour efficiency of the battery is

Discussion

14.	A 70 kg man stands in contact against the inner wall of a hollow cylindrical drum of radius 3 m rotating about its vertical axis. The coefficient of friction between the wall and his clothing is 0.15. What is the minimum rotational speed in rad/s of the cylinder to enable the man to remain stuck to the wall (without falling) when the floor is suddenly removed? Take g=10 ms−2
Answer» A $70 k g$ man stands in contact against the inner wall of a hollow cylindrical drum of radius $3 m$ rotating about its vertical axis. The coefficient of friction between the wall and his clothing is $0.15$ . What is the minimum rotational speed in $r a d / s$ of the cylinder to enable the man to remain stuck to the wall (without falling) when the floor is suddenly removed? Take $g = 10 m s^{- 2}$

Discussion

15.	A ball is projected from a certain point on the ground at an angle with the horizontal surface. The horizontal and vertical displacement x and y(in metres) vary with time (in seconds) as x=10√3t y=10t−5t2 What is the magnitude and direction of the velocity of projection?
Answer» A ball is projected from a certain point on the ground at an angle with the horizontal surface. The horizontal and vertical displacement x and y(in metres) vary with time (in seconds) as $x = 10 \sqrt{3} t$ $y = 10 t - 5 t^{2}$ What is the magnitude and direction of the velocity of projection?

Discussion

16.	The value of the integral 1√2∫0sin−1x dx(1−x2)32
Answer» The value of the integral $\frac{1}{\sqrt{2}} \int 0 \frac{{sin}^{- 1} x d x}{(1 - x^{2})^{\frac{3}{2}}}$

Discussion

17.	Displacement y=Asin(Bx+Ct+D),x in metres and t in seconds.find dimension of ABCD
Answer» Displacement y=Asin(Bx+Ct+D),x in metres and t in seconds.find dimension of ABCD

Discussion

18.	Points P,Q,R are in a vertical line such that PQ=QR.A. A ball at P is allowed to fall freely. What is the ratio of the descent through PQ and QR
Answer» Points P,Q,R are in a vertical line such that PQ=QR.A. A ball at P is allowed to fall freely. What is the ratio of the descent through PQ and QR

Discussion

19.	If the radius of curvature of the path of two particles of same masses are in the ratio 1:3, then in order to have same centripetal force, their velocity should be in the ratio of
Answer» If the radius of curvature of the path of two particles of same masses are in the ratio $1 : 3$ , then in order to have same centripetal force, their velocity should be in the ratio of

Discussion

20.	A satellite which is geostationary in a particular orbit is taken to another orbit. Its distance from the centre of earth in new orbit is 2 times that of the earlier orbit. The time period in second orbit is?
Answer» A satellite which is geostationary in a particular orbit is taken to another orbit. Its distance from the centre of earth in new orbit is 2 times that of the earlier orbit. The time period in second orbit is?

Discussion

21.	prove that the phase difference between displacement and velocity of an object in shm is pi/2.
Answer» prove that the phase difference between displacement and velocity of an object in shm is pi/2.

Discussion

22.	Select the correct statements regarding the positron which is an elementary particle: Code:
Answer» Select the correct statements regarding the positron which is an elementary particle: Code:

22.

Select the correct statements regarding the positron which is an elementary particle: Code:

Answer»

Select the correct statements regarding the positron which is an elementary particle:

Code:

Discussion

23.	Power supplied to a particle of mass 2 kg varies with time as P=3t22 W, where t is in seconds. If velocity of particle at t=0 is v=0, the magnitude of velocity of particle at time t=2 s will be
Answer» Power supplied to a particle of mass $2 kg$ varies with time as $P = \frac{3 t^{2}}{2} W$ , where $t$ is in seconds. If velocity of particle at $t = 0$ is $v = 0$ , the magnitude of velocity of particle at time $t = 2 s$ will be

Discussion

24.	Work done by 0.1 mole of a gas at 27∘C to double its volume at constant pressure is [Take R=2 cal mol−1K−1]
Answer» Work done by $0.1 mole$ of a gas at $27^{\circ} C$ to double its volume at constant pressure is [Take $R = 2 {cal mol}^{- 1} K^{- 1}$ ]

Discussion

25.	An alternating current is given by i=i1cosωt+i2sinωt. The rms current is given by
Answer» An alternating current is given by $i = i_{1} cos ω t + i_{2} sin ω t$ . The rms current is given by

Discussion

26.	Two waves propagating in a given medium are represented by the curve shown below. Find the ratio of average potential energy per unit length of wave 1 is to wave 2. All measurements are in S.I unit.
Answer» Two waves propagating in a given medium are represented by the curve shown below. Find the ratio of average potential energy per unit length of wave $1$ is to wave $2$ . All measurements are in $S.I$ unit.

Discussion

27.	How can I calculate percentage error of colour coding of resistor ?
Answer» How can I calculate percentage error of colour coding of resistor ?

Discussion

28.	Two blocks of equal masses are placed on a horizontal surface. The surface of A is smooth but that of B has a friction coefficient of 0.2 with the floor. Block A is given a speed 5 m/s, towards B which is kept at rest. Find the distance travelled by B, if the collision is perfectly elastic. (take g=10 m/s2 )
Answer» Two blocks of equal masses are placed on a horizontal surface. The surface of $A$ is smooth but that of $B$ has a friction coefficient of $0.2$ with the floor. Block $A$ is given a speed $5 m/s$ , towards $B$ which is kept at rest. Find the distance travelled by $B$ , if the collision is perfectly elastic. (take $g = 10 {m/s}^{2}$ )

Discussion

29.	The sum of two forces acting at a point is 16 N. If the resultant force is 8 N and its direction is perpendicular to minimum force then the forces are
Answer» The sum of two forces acting at a point is 16 N. If the resultant force is 8 N and its direction is perpendicular to minimum force then the forces are

Discussion

30.	The set of values of k for which x2−kx+sin−1(sin4)>0 for all real x is
Answer» The set of values of k for which $x^{2} - k x + s i n^{- 1} (s i n 4) > 0$ for all real x is

Discussion

31.	A ring has greater moment of inertia than a circular disc of same mass and radius, about an axis passing through its centre of mass perpendicular to its plane, because
Answer» A ring has greater moment of inertia than a circular disc of same mass and radius, about an axis passing through its centre of mass perpendicular to its plane, because

Discussion

32.	Two blocks of the masses 10 kg and 4 kg are connected by a spring of negligible mass and placed on a frictionless horizontal surface. An impulse gives a velocity of 14 m/s to the heavier block. The velocity of centre of mass is
Answer» Two blocks of the masses 10 kg and 4 kg are connected by a spring of negligible mass and placed on a frictionless horizontal surface. An impulse gives a velocity of 14 m/s to the heavier block. The velocity of centre of mass is

Discussion

33.	A bus moves from stop A to the next stop B. Its acceleration varies as a=α−βx, where α and β are positive constants and x is the distance from the stop A to stop B. The distance between A and B and the maximum speed of the bus are
Answer» A bus moves from stop $A$ to the next stop $B$ . Its acceleration varies as $a = α - β x$ , where $α$ and $β$ are positive constants and $x$ is the distance from the stop $A$ to stop $B$ . The distance between $A$ and $B$ and the maximum speed of the bus are

Discussion

34.	A wire abc is carrying current I. It is bent as shown in the figure and is placed in a uniform magnetic field B. Length ab = l and ∠abc=45∘. What is the ratio of force on bc to that on ab?
Answer» A wire abc is carrying current I. It is bent as shown in the figure and is placed in a uniform magnetic field B. Length ab = l and $∠ a b c = 45^{\circ}$ . What is the ratio of force on bc to that on ab?

Discussion

35.	A projectile has initially the same horizontal velocity as it would acquire if it had moved from rest with uniform acceleration of 3 m/s2 for 0.5 min. If the maximum height reached by it is 80 m, then the angle of projection is (g=10 m/s2)
Answer» A projectile has initially the same horizontal velocity as it would acquire if it had moved from rest with uniform acceleration of $3 {m/s}^{2}$ for $0.5$ min. If the maximum height reached by it is $80 m$ , then the angle of projection is ( $g = 10 {m/s}^{2}$ )

Discussion

36.	A hollow metallic sphere of radius R is given a charge Q. The potential at its centre is
Answer» A hollow metallic sphere of radius R is given a charge Q. The potential at its centre is

Discussion

37.	A body of mass m hangs from three springs, each of spring constant K, as shown. If the mass is slightly displaced and released, the system will oscillate with time period of
Answer» A body of mass $m$ hangs from three springs, each of spring constant $K$ , as shown. If the mass is slightly displaced and released, the system will oscillate with time period of

Discussion

38.	Find the dimensions of Planck's constant h from the equation E = hv where E is the energy and v is the frequency.
Answer» Find the dimensions of Planck's constant h from the equation E = hv where E is the energy and v is the frequency.

Discussion

39.	A string of length 40 cm and weighing 10 g is attached to a spring at one end to a fixed wall at the other end. The spring has a spring constant of 160 N m−1 and is stretched by 1.0 cm. If a wave pulse is produced on the string near the wall, how much time will it take to reach the spring ?
Answer» A string of length 40 cm and weighing 10 g is attached to a spring at one end to a fixed wall at the other end. The spring has a spring constant of $160 N m^{- 1}$ and is stretched by 1.0 cm. If a wave pulse is produced on the string near the wall, how much time will it take to reach the spring ?

Discussion

40.	A stone is thrown upwards from the top of a tower 85 m high . It reaches the ground in 5s . Calculate 1) the greatest height above the ground 2) the velocity with which it reaches the ground 3) the time taken to reach the maximum height.(g=10 m/ s2)
Answer» A stone is thrown upwards from the top of a tower 85 m high . It reaches the ground in 5s . Calculate 1) the greatest height above the ground 2) the velocity with which it reaches the ground 3) the time taken to reach the maximum height.(g=10 m/ s²)

40.

A stone is thrown upwards from the top of a tower 85 m high . It reaches the ground in 5s . Calculate 1) the greatest height above the ground 2) the velocity with which it reaches the ground 3) the time taken to reach the maximum height.(g=10 m/ s2)

Answer»

A stone is thrown upwards from the top of a tower 85 m high . It reaches the ground in 5s . Calculate

1) the greatest height above the ground

2) the velocity with which it reaches the ground

3) the time taken to reach the maximum height.(g=10 m/ s²)

Discussion

41.	On a winter day sound travels 336 meters in one second. Find the atmospheric temperature. Speed of sound at 0∘ C = 332 m s−1.
Answer» On a winter day sound travels 336 meters in one second. Find the atmospheric temperature. Speed of sound at 0 $^{\circ}$ C = 332 m s $^{- 1}$ .

Discussion

42.	Two solid spherical balls of mass m, radius r attached at the two ends of a thin straight rod of mass m and length 4r as shown in the figure.If this system is free to rotate about an axis passing through an end of the rod and along diameter of one of the spheres, find moment of inertia of the system about this axis.
Answer» Two solid spherical balls of mass $m$ , radius $r$ attached at the two ends of a thin straight rod of mass $m$ and length $4 r$ as shown in the figure.If this system is free to rotate about an axis passing through an end of the rod and along diameter of one of the spheres, find moment of inertia of the system about this axis.

Discussion

43.	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

44.	As shown in figure the tension in the horizontal cord is 20 N. The weight W and tension in the string OA in Newton are
Answer» As shown in figure the tension in the horizontal cord is 20 N. The weight W and tension in the string OA in Newton are

Discussion

45.	A ring of radius 100 cm has a uniformly distributed charge Q and uniformly distributed mass m. On the axis a point charge –Q of mass 2m is placed at a distance 3 cm form its centre. Both are released from rest. Assuming only electric interaction between the ring and particle, find the amplitude (in cm) of SHM of particle.___
Answer» A ring of radius 100 cm has a uniformly distributed charge Q and uniformly distributed mass m. On the axis a point charge –Q of mass 2m is placed at a distance 3 cm form its centre. Both are released from rest. Assuming only electric interaction between the ring and particle, find the amplitude (in cm) of SHM of particle.___

45.

A ring of radius 100 cm has a uniformly distributed charge Q and uniformly distributed mass m. On the axis a point charge –Q of mass 2m is placed at a distance 3 cm form its centre. Both are released from rest. Assuming only electric interaction between the ring and particle, find the amplitude (in cm) of SHM of particle.___

Answer»

A ring of radius 100 cm has a uniformly distributed charge Q and uniformly distributed mass m. On the axis a point charge –Q of mass 2m is placed at a distance 3 cm form its centre. Both are released from rest. Assuming only electric interaction between the ring and particle, find the amplitude (in cm) of SHM of particle.___

Discussion

46.	A rectangular loop with a sliding connector of length l = 10 m is situated in a uniform magnetic field B = 2T perpendicular to the plane of loop. Resistance of connector is r=2Ω. Two resistance of 6Ω and 3Ω are connected as shown in figure. The external force required to keep the connector moving with a constant velocity v= 2 m/s is
Answer» A rectangular loop with a sliding connector of length l = 10 m is situated in a uniform magnetic field B = 2T perpendicular to the plane of loop. Resistance of connector is $r = 2 Ω$ . Two resistance of $6 Ω$ and $3 Ω$ are connected as shown in figure. The external force required to keep the connector moving with a constant velocity v= 2 m/s is

46.

A rectangular loop with a sliding connector of length l = 10 m is situated in a uniform magnetic field B = 2T perpendicular to the plane of loop. Resistance of connector is r=2Ω. Two resistance of 6Ω and 3Ω are connected as shown in figure. The external force required to keep the connector moving with a constant velocity v= 2 m/s is

Answer»

A rectangular loop with a sliding connector of length l = 10 m is situated in a uniform magnetic field B = 2T perpendicular to the plane of loop. Resistance of connector is $r = 2 Ω$ . Two resistance of $6 Ω$ and $3 Ω$ are connected as shown in figure. The external force required to keep the connector moving with a constant velocity v= 2 m/s is

Discussion

47.	If an electron and a proton having same momenta enter perpendicular to a magnetic field, then
Answer» If an electron and a proton having same momenta enter perpendicular to a magnetic field, then

Discussion

48.	A solid copper sphere of density ρ, specific heat c and radius r is at temperature T1. It is suspended inside a chamber whose walls are at temperature 0 K. The time required for the temperature of sphere to drop to T2 is rρcxeσ(1T32−1T31). Find the value of x ?Take the emmissivity of the sphere to be equal to e.
Answer» A solid copper sphere of density $ρ,$ specific heat $c$ and radius $r$ is at temperature $T_{1}$ . It is suspended inside a chamber whose walls are at temperature $0 K$ . The time required for the temperature of sphere to drop to $T_{2}$ is $\frac{r ρ c}{x e σ} (\frac{1}{T_{2}^{3}} - \frac{1}{T_{1}^{3}})$ . Find the value of $x$ ? Take the emmissivity of the sphere to be equal to $e$ .

Discussion

49.	The force exerted by a stretched chord at given displacements is shown in the table given below. Experimentally, the force is found to vary proportionally to the square of the displacement, i.e. F(x)=−hx2 where h is some constant. If the potential energy at x=0 m is U0=0 J, determine the potential energy at x=1.5 m.
Answer» The force exerted by a stretched chord at given displacements is shown in the table given below. Experimentally, the force is found to vary proportionally to the square of the displacement, i.e. $F (x) = - h x^{2}$ where $h$ is some constant. If the potential energy at $x = 0 m$ is $U_{0} = 0 J$ , determine the potential energy at $x = 1.5 m$ .

Discussion

50.	A point source of power 50π W is producing sound waves of frequency 1876 Hz. What is the pressure amplitude at a distance √330 m from the point source? [Speed of sound is 330 m/s and density of air is 1 kg/m3]
Answer» A point source of power $50 π W$ is producing sound waves of frequency $1876 Hz$ . What is the pressure amplitude at a distance $\sqrt{330} m$ from the point source? [Speed of sound is $330 m/s$ and density of air is $1 {kg/m}^{3}$ ]

Discussion

Explore topic-wise InterviewSolutions in Current Affairs.

A stone is dropped into a well in which the level of water is h below the top of well. If V is the velocity of sound, the time T after which the splash is heard is given by

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Two bars of same length and same cross-sectional area but of different thermal conductivities K1 and K2 are joined end to end as shown in the figure. One end of the compound bar is at temperature T1 and the opposite end at temperature T2 (where T1&gt;T2).The temperature of the junction is

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prove that the phase difference between displacement and velocity of an object in shm is pi/2.

Select the correct statements regarding the positron which is an elementary particle: Code:

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An alternating current is given by i=i1cosωt+i2sinωt. The rms current is given by

Two waves propagating in a given medium are represented by the curve shown below. Find the ratio of average potential energy per unit length of wave 1 is to wave 2. All measurements are in S.I unit.

How can I calculate percentage error of colour coding of resistor ?

The sum of two forces acting at a point is 16 N. If the resultant force is 8 N and its direction is perpendicular to minimum force then the forces are

The set of values of k for which x2−kx+sin−1(sin4)&gt;0 for all real x is

A ring has greater moment of inertia than a circular disc of same mass and radius, about an axis passing through its centre of mass perpendicular to its plane, because

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A bus moves from stop A to the next stop B. Its acceleration varies as a=α−βx, where α and β are positive constants and x is the distance from the stop A to stop B. The distance between A and B and the maximum speed of the bus are

A wire abc is carrying current I. It is bent as shown in the figure and is placed in a uniform magnetic field B. Length ab = l and ∠abc=45∘. What is the ratio of force on bc to that on ab?

A projectile has initially the same horizontal velocity as it would acquire if it had moved from rest with uniform acceleration of 3 m/s2 for 0.5 min. If the maximum height reached by it is 80 m, then the angle of projection is (g=10 m/s2)

A hollow metallic sphere of radius R is given a charge Q. The potential at its centre is

A body of mass m hangs from three springs, each of spring constant K, as shown. If the mass is slightly displaced and released, the system will oscillate with time period of

Find the dimensions of Planck's constant h from the equation E = hv where E is the energy and v is the frequency.

A string of length 40 cm and weighing 10 g is attached to a spring at one end to a fixed wall at the other end. The spring has a spring constant of 160 N m−1 and is stretched by 1.0 cm. If a wave pulse is produced on the string near the wall, how much time will it take to reach the spring ?

A stone is thrown upwards from the top of a tower 85 m high . It reaches the ground in 5s . Calculate 1) the greatest height above the ground 2) the velocity with which it reaches the ground 3) the time taken to reach the maximum height.(g=10 m/ s​​​​​​2)

On a winter day sound travels 336 meters in one second. Find the atmospheric temperature. Speed of sound at 0∘ C = 332 m s−1.

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

As shown in figure the tension in the horizontal cord is 20 N. The weight W and tension in the string OA in Newton are

If an electron and a proton having same momenta enter perpendicular to a magnetic field, then

A point source of power 50π W is producing sound waves of frequency 1876 Hz. What is the pressure amplitude at a distance √330 m from the point source? [Speed of sound is 330 m/s and density of air is 1 kg/m3]

Two bars of same length and same cross-sectional area but of different thermal conductivities K1 and K2 are joined end to end as shown in the figure. One end of the compound bar is at temperature T1 and the opposite end at temperature T2 (where T1>T2).The temperature of the junction is

The set of values of k for which x2−kx+sin−1(sin4)>0 for all real x is

A stone is thrown upwards from the top of a tower 85 m high . It reaches the ground in 5s . Calculate 1) the greatest height above the ground 2) the velocity with which it reaches the ground 3) the time taken to reach the maximum height.(g=10 m/ s2)