Physics-
General
Easy
Question
A conducting disc of radius R is placed in a uniform and constant magnetic field B parallel to the axis of the disc. With what angular speed should the disc be rotated about its axis such that no electric field develops in the disc. (the electronic charge and mass are e and m)
The correct answer is:
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Some magnetic flux is changed in a coil of resistance 10 ohm. As a result an induced current is developed in it, which varies with time as shown in figure. The magnitude of change in flux through the coil in Weber’s is (Neglect self-inductance of the coil)
Some magnetic flux is changed in a coil of resistance 10 ohm. As a result an induced current is developed in it, which varies with time as shown in figure. The magnitude of change in flux through the coil in Weber’s is (Neglect self-inductance of the coil)
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When induced emf in inductor coil is 50% of its maximum value then stored energy in inductor coil in the given circuit will be : -
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A uniform magnetic field, B = B0 t (where B0 is a positive constant), fills a cylindrical volume of radius R, then the potential difference in the conducting rod PQ due to electrostatic field is :
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A conducting rod AB moves with a uniform velocity v in a constant magnetic field as shown in fig.
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Fig. shows a conducting loop being pulled out of a magnetic field with a constant speed v. Which of the four plots shown in fig. may represent the power delivered by the pulling agent as a function of the constant speed v.
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chemistry-
Aqueous solution of which of the following shows lower pH?
Aqueous solution of which of the following shows lower pH?
chemistry-General
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The following has lowest pH
The following has lowest pH
chemistry-General
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In the figure shown a square loop PQRS of side 'a' and resistance 'r' is placed near an infinitely long wire carrying a constant current I. The sides PQ and RS are parallel to the wire. The wire and the loop are in the same plane. The loop is rotated by about an axis parallel to the long wire and passing through the mid points of the side QR and PS. The total amount of charge which passes through any point of the loop during rotation is :
In the figure shown a square loop PQRS of side 'a' and resistance 'r' is placed near an infinitely long wire carrying a constant current I. The sides PQ and RS are parallel to the wire. The wire and the loop are in the same plane. The loop is rotated by about an axis parallel to the long wire and passing through the mid points of the side QR and PS. The total amount of charge which passes through any point of the loop during rotation is :
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The battery shown in the figure is ideal. The values are e = 10 V, R = 5, L = 2H . Initially the current in the inductor is zero. The current through the battery at t = 2s is
The battery shown in the figure is ideal. The values are e = 10 V, R = 5, L = 2H . Initially the current in the inductor is zero. The current through the battery at t = 2s is
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When the current in the portion of the circuit shown in the figure is 2A and increasing at the rate of 1A/s, the measured potential difference . However when the current is 2A and decreasing at the rate of 1A/s, the measured potential difference . The values of R and L are :
When the current in the portion of the circuit shown in the figure is 2A and increasing at the rate of 1A/s, the measured potential difference . However when the current is 2A and decreasing at the rate of 1A/s, the measured potential difference . The values of R and L are :
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A conducting wire frame is placed in a magnetic field which is directed into the paper. The magnetic field is increasing at a constant rate. The directions of induced currents in wires AB and CD are :
A conducting wire frame is placed in a magnetic field which is directed into the paper. The magnetic field is increasing at a constant rate. The directions of induced currents in wires AB and CD are :
physics-General
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A non conducting ring of radius R and mass m having charge q uniformly distributed over its circumference is placed on a rough horizontal surface. A vertical time varying uniform magnetic field is switched on at time t=0. The coefficient of friction between the ring and the table, if the ring starts rotating at t =2 sec, is
A non conducting ring of radius R and mass m having charge q uniformly distributed over its circumference is placed on a rough horizontal surface. A vertical time varying uniform magnetic field is switched on at time t=0. The coefficient of friction between the ring and the table, if the ring starts rotating at t =2 sec, is
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Two inductor coils of self inductance 3H and 6H respectively are connected with a resistance 10 and a battery 10 V as shown in figure. The ratio of total energy stored at steady state in the inductors to that of heat developed in resistance in 10 seconds at the steady state is (neglect mu(tual inductance between and ):
Two inductor coils of self inductance 3H and 6H respectively are connected with a resistance 10 and a battery 10 V as shown in figure. The ratio of total energy stored at steady state in the inductors to that of heat developed in resistance in 10 seconds at the steady state is (neglect mu(tual inductance between and ):
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An infinitely long wire lying along z-axis carries a current I, flowing towards positive z-direction. There is no other current, consider a circle in x-y plane with centre at (2 meter, 0, 0) and radius 1 meter. Divide the circle in small segments and let d denote the length of a small segment in anticlockwise direction, as shown.
The maximum value of path integral of the total magnetic field along the perimeter of the given circle between any two points on the circle is
An infinitely long wire lying along z-axis carries a current I, flowing towards positive z-direction. There is no other current, consider a circle in x-y plane with centre at (2 meter, 0, 0) and radius 1 meter. Divide the circle in small segments and let d denote the length of a small segment in anticlockwise direction, as shown.
The maximum value of path integral of the total magnetic field along the perimeter of the given circle between any two points on the circle is
physics-General
physics-
An infinitely long wire lying along z-axis carries a current I, flowing towards positive z-direction. There is no other current, consider a circle in x-y plane with centre at (2 meter, 0, 0) and radius 1 meter. Divide the circle in small segments and let d denote the length of a small segment in anticlockwise direction, as shown.
Consider two points A (3,0,0) and B(2,1,0) on the given circle. The path integral of the total magnetic field along the perimeter of the given circle from A to B is,
An infinitely long wire lying along z-axis carries a current I, flowing towards positive z-direction. There is no other current, consider a circle in x-y plane with centre at (2 meter, 0, 0) and radius 1 meter. Divide the circle in small segments and let d denote the length of a small segment in anticlockwise direction, as shown.
Consider two points A (3,0,0) and B(2,1,0) on the given circle. The path integral of the total magnetic field along the perimeter of the given circle from A to B is,
physics-General
