3731 + Interview Questions in Physics Page 75 InterviewSolution

3701.	An inductor of inductance 20 mH, a capacitor of capacitance 100 µF and a resistor of resistance 50 Ω are connected in series across a source of emf, V = 10sin(314t). The power loss in the circuit is
Answer» An inductor of inductance $20 m H$ , a capacitor of capacitance $100 µ F$ and a resistor of resistance $50 Ω$ are connected in series across a source of emf, $V = 10 sin (314 t)$ . The power loss in the circuit is

Discussion

3702.	A light ray is incident perpendicular to a face of a 90∘ prism and is totally internally reflected at the glass – air interface. If the angle of reflection is 45∘, what can be concluded about the refractive index n?
Answer» A light ray is incident perpendicular to a face of a $90^{\circ}$ prism and is totally internally reflected at the glass – air interface. If the angle of reflection is $45^{\circ}$ , what can be concluded about the refractive index n?

Discussion

3703.	A particle undergoes three successive displacements given by S1=√2 m north-east, S2=2 m due south and S3=4 m, 30∘ north of west, then magnitude of net displacement is
Answer» A particle undergoes three successive displacements given by $S_{1} = \sqrt{2} m$ north-east, $S_{2} = 2 m$ due south and $S_{3} = 4 m$ , $30^{\circ}$ north of west, then magnitude of net displacement is

Discussion

3704.	The approximate wavelength of a photon of energy 2.48 eV is
Answer» The approximate wavelength of a photon of energy 2.48 eV is

Discussion

3705.	A car travels a distance of 300 km in 10 hours, the average speed of the car is
Answer» A car travels a distance of 300 km in 10 hours, the average speed of the car is

Discussion

3706.	A spring block system is performing SHM with a time period of 4 s. If at any instant, the kinetic energy of the system is represented as KE and potential energy as KP, then what is the time period of oscillation of KE−KP?
Answer» A spring block system is performing $S H M$ with a time period of $4 s$ . If at any instant, the kinetic energy of the system is represented as $K_{E}$ and potential energy as $K_{P}$ , then what is the time period of oscillation of $K_{E} - K_{P}$ ?

Discussion

3707.	Magnetic field intensity is defined as
Answer» Magnetic field intensity is defined as

Discussion

3708.	A uniform rod of length L (in between the supports) and mass m is placed on two hinges A and B. The rod breaks suddenly at length L10 from the support B. Find the reaction at hinge A immediately after the rod breaks :
Answer» A uniform rod of length $L$ (in between the supports) and mass m is placed on two hinges A and B. The rod breaks suddenly at length $\frac{L}{10}$ from the support B. Find the reaction at hinge A immediately after the rod breaks :

Discussion

3709.	In an experiment, the saturation in the plate current in a diode is observed at 240V. But a student still wants to increase the plate current. It can be done, if
Answer» In an experiment, the saturation in the plate current in a diode is observed at 240V. But a student still wants to increase the plate current. It can be done, if

Discussion

3710.	If →Vr is the velocity of rain falling vertically and −→Vm is the velocity of a man walking on a level road, and θ is the angle with vertical at which he should hold the umbrella to protect himself, then the magnitude of relative velocity of rain w.r.t man is given by
Answer» If $_{r}$ is the velocity of rain falling vertically and $_{m}$ is the velocity of a man walking on a level road, and $θ$ is the angle with vertical at which he should hold the umbrella to protect himself, then the magnitude of relative velocity of rain w.r.t man is given by

Discussion

3711.	A point object of mass m moving horizontally hits the uniform solid disc and stick to it. The disc is resting on a horizontal frictionless surface and pivoted at its centre as shown in figure. Find out the MOI of the disc if it rotates with angular velocity ω=v5R after the strike.
Answer» A point object of mass $m$ moving horizontally hits the uniform solid disc and stick to it. The disc is resting on a horizontal frictionless surface and pivoted at its centre as shown in figure. Find out the $M O I$ of the disc if it rotates with angular velocity $ω = \frac{v}{5 R}$ after the strike.

Discussion

3712.	Find the moment of inertia of a uniform rod of mass M and length L, about OA {PQ makes an angle of 30∘ with OA as shown in figure}.
Answer» Find the moment of inertia of a uniform rod of mass $M$ and length $L$ , about $O A$ { $P Q$ makes an angle of $30^{\circ}$ with $O A$ as shown in figure}.

3712.

Find the moment of inertia of a uniform rod of mass M and length L, about OA {PQ makes an angle of 30∘ with OA as shown in figure}.

Answer»

Find the moment of inertia of a uniform rod of mass $M$ and length $L$ , about $O A$ { $P Q$ makes an angle of $30^{\circ}$ with $O A$ as shown in figure}.

Discussion

3713.	A rope is stretched between two boats at rest. A sailor in the first boat pulls the rope with a constant force of 100 N. First boat with the sailor has a mass of 250 kg whereas the mass of second boat is double of this mass. If the initial distance between the boats was 100 m, the time taken for two boats to meet each other in seconds is (neglect water resistance between boats and water). Answer the nearest integer.
Answer» A rope is stretched between two boats at rest. A sailor in the first boat pulls the rope with a constant force of 100 N. First boat with the sailor has a mass of 250 kg whereas the mass of second boat is double of this mass. If the initial distance between the boats was 100 m, the time taken for two boats to meet each other in seconds is (neglect water resistance between boats and water). Answer the nearest integer.

Discussion

3714.	Consider a block of mass 10 kg collides with a spring of spring constant 10 N/m. The speed of block is 5 m/s, when the compression in spring is 2 m. Calculate the speed of the block, when compression is 5 m?
Answer» Consider a block of mass $10 kg$ collides with a spring of spring constant $10 N/m$ . The speed of block is $5 m/s$ , when the compression in spring is $2 m$ . Calculate the speed of the block, when compression is $5 m$ ?

Discussion

3715.	A uniform ring and uniform sphere are placed as shown in the figure. The gravitational attraction between the sphere and ring (d=√3R) is.
Answer» A uniform ring and uniform sphere are placed as shown in the figure. The gravitational attraction between the sphere and ring ( $d = \sqrt{3} R$ ) is.

Discussion

3716.	A cubical block of ice floating in water has to support a metal piece of mass 0.5 kg. If specific gravity of ice is 0.9, then minimum edge length (in m) of the block so that it does not sink in water is
Answer» A cubical block of ice floating in water has to support a metal piece of mass $0.5 kg$ . If specific gravity of ice is $0.9$ , then minimum edge length (in $m$ ) of the block so that it does not sink in water is

Discussion

3717.	Find the potential V of an electrostatic field →E=a(y^i+x^j), where a is a constant.
Answer» Find the potential $V$ of an electrostatic field $\to E = a (y^i + x^j),$ where a is a constant.

Discussion

3718.	A planet has radius equal to 2RE and density is equal to 4ρE. If the value of escape speed at surface of planet is α times vE (vE is escape speed on earth, RE is radius of earth and ρE is the density of earth) then -
Answer» A planet has radius equal to $2 R_{E}$ and density is equal to $4 ρ_{E}$ . If the value of escape speed at surface of planet is $α$ times $v_{E}$ $(v_{E}$ is escape speed on earth, $R_{E}$ is radius of earth and $ρ_{E}$ is the density of earth $)$ then -

Discussion

3719.	Which of the following processes will be least affected by the viscosity of water ?
Answer» Which of the following processes will be least affected by the viscosity of water ?

Discussion

3720.	Identify "Periodic Motion”?
Answer» Identify "Periodic Motion”?

Discussion

3721.	When a body rolls without sliding, up an inclined plane, the frictional force is
Answer» When a body rolls without sliding, up an inclined plane, the frictional force is

Discussion

3722.	A ray of light makes an angle of 10∘ with the horizontal above it and strikes a plane mirror which is inclined at an angle θ to the horizontal. The angle θ for which the reflected ray becomes vertical is
Answer» A ray of light makes an angle of $10^{\circ}$ with the horizontal above it and strikes a plane mirror which is inclined at an angle $θ$ to the horizontal. The angle $θ$ for which the reflected ray becomes vertical is

Discussion

3723.	The densities of two spheres A and B of the same radii R vary with radial distance r as pA(r)=k(rR) and pB(r)=k(rR)5, respectively, where k is a constant. The moments of inertia of the individual spheres about axes passing through their centres are IA and IB, respectively, If IBIA=n10, the value of n is: ___
Answer» The densities of two spheres A and B of the same radii R vary with radial distance r as $p_{A} (r) = k (\frac{r}{R})$ and $p_{B} (r) = k (\frac{r}{R})^{5},$ respectively, where k is a constant. The moments of inertia of the individual spheres about axes passing through their centres are $I_{A} a n d I_{B},$ respectively, If $\frac{I_{B}}{I_{A}} = \frac{n}{10},$ the value of n is: ___

Discussion

3724.	The rate at which the velocity of a freely falling body increases is called
Answer» The rate at which the velocity of a freely falling body increases is called

Discussion

3725.	In Galileo's experiment in order to reach the same height how far must the ball go on the horizontal surface after being released from an incline of a height of 5m?
Answer» In Galileo's experiment in order to reach the same height how far must the ball go on the horizontal surface after being released from an incline of a height of 5m?

Discussion

3726.	A closed organ pipe can vibrate at a minimum frequency of 500 Hz. Find the length of the tube. Speed of sound in air = 340 ms−1.
Answer» A closed organ pipe can vibrate at a minimum frequency of 500 Hz. Find the length of the tube. Speed of sound in air = $340 m s^{- 1}$ .

Discussion

3727.	Find the integration of ∫etan−1x1+x2.dx
Answer» Find the integration of $\int \frac{e^{{tan}^{- 1} x}}{1 + x^{2}} . d x$

Discussion

Explore topic-wise InterviewSolutions in .

An inductor of inductance 20 mH, a capacitor of capacitance 100 µF and a resistor of resistance 50 Ω are connected in series across a source of emf, V = 10sin(314t). The power loss in the circuit is

A light ray is incident perpendicular to a face of a 90∘ prism and is totally internally reflected at the glass – air interface. If the angle of reflection is 45∘, what can be concluded about the refractive index n?

A particle undergoes three successive displacements given by S1=√2 m north-east, S2=2 m due south and S3=4 m, 30∘ north of west, then magnitude of net displacement is

The approximate wavelength of a photon of energy 2.48 eV is

A car travels a distance of 300 km in 10 hours, the average speed of the car is

A spring block system is performing SHM with a time period of 4 s. If at any instant, the kinetic energy of the system is represented as KE and potential energy as KP, then what is the time period of oscillation of KE−KP?

Magnetic field intensity is defined as

A uniform rod of length L (in between the supports) and mass m is placed on two hinges A and B. The rod breaks suddenly at length L10 from the support B. Find the reaction at hinge A immediately after the rod breaks :

In an experiment, the saturation in the plate current in a diode is observed at 240V. But a student still wants to increase the plate current. It can be done, if

If →Vr is the velocity of rain falling vertically and −→Vm is the velocity of a man walking on a level road, and θ is the angle with vertical at which he should hold the umbrella to protect himself, then the magnitude of relative velocity of rain w.r.t man is given by

A point object of mass m moving horizontally hits the uniform solid disc and stick to it. The disc is resting on a horizontal frictionless surface and pivoted at its centre as shown in figure. Find out the MOI of the disc if it rotates with angular velocity ω=v5R after the strike.

Find the moment of inertia of a uniform rod of mass M and length L, about OA {PQ makes an angle of 30∘ with OA as shown in figure}.

Consider a block of mass 10 kg collides with a spring of spring constant 10 N/m. The speed of block is 5 m/s, when the compression in spring is 2 m. Calculate the speed of the block, when compression is 5 m?

A uniform ring and uniform sphere are placed as shown in the figure. The gravitational attraction between the sphere and ring (d=√3R) is.

A cubical block of ice floating in water has to support a metal piece of mass 0.5 kg. If specific gravity of ice is 0.9, then minimum edge length (in m) of the block so that it does not sink in water is

Find the potential V of an electrostatic field →E=a(y^i+x^j), where a is a constant.

A planet has radius equal to 2RE and density is equal to 4ρE. If the value of escape speed at surface of planet is α times vE (vE is escape speed on earth, RE is radius of earth and ρE is the density of earth) then -

Which of the following processes will be least affected by the viscosity of water ?

Identify "Periodic Motion”?

When a body rolls without sliding, up an inclined plane, the frictional force is

A ray of light makes an angle of 10∘ with the horizontal above it and strikes a plane mirror which is inclined at an angle θ to the horizontal. The angle θ for which the reflected ray becomes vertical is

The rate at which the velocity of a freely falling body increases is called

In Galileo's experiment in order to reach the same height how far must the ball go on the horizontal surface after being released from an incline of a height of 5m?

A closed organ pipe can vibrate at a minimum frequency of 500 Hz. Find the length of the tube. Speed of sound in air = 340 ms−1.

Find the integration of ∫etan−1x1+x2.dx