Physics-
General
Easy

Question

A wire cd of length l and mass m is sliding without friction on conducting rails ax and by as shown. The vertical rails are connected to each other with a resistance R between a and b. A uniform magnetic field B is applied perpendicular to the plane abcd such that cd moves with a constant velocity of

  1. fraction numerator m g R over denominator B l end fraction    
  2. fraction numerator m g R over denominator B to the power of 2 end exponent l to the power of 2 end exponent end fraction    
  3. fraction numerator m g R over denominator B to the power of 3 end exponent l to the power of 3 end exponent end fraction    
  4. fraction numerator m g R over denominator B to the power of 2 end exponent l end fraction    

The correct answer is: fraction numerator m g R over denominator B to the power of 2 end exponent l to the power of 2 end exponent end fraction


    Due to magnetic field, wire will experience an upward force F equals B i l equals B   open parentheses fraction numerator B v l over denominator R end fraction close parentheses   l rightwards double arrow F equals fraction numerator B to the power of 2 end exponent v l to the power of 2 end exponent over denominator R end fraction
    If wire slides down with constant velocity then
    F equals m g rightwards double arrow fraction numerator B to the power of 2 end exponent v l to the power of 2 end exponent over denominator R end fraction equals m g rightwards double arrow v equals fraction numerator m g R over denominator B to the power of 2 end exponent l to the power of 2 end exponent end fraction

    Related Questions to study

    General
    Physics-

    A rectangular loop with a sliding connector of length l = 1.0 m is situated in a uniform magnetic field B = 2T perpendicular to the plane of loop. Resistance of connector is r = 2capital omega. Two resistance of 6capital omega and 3capital omega are connected as shown in figure. The external force required to keep the connector moving with a constant velocity v = 2m/s is

    A rectangular loop with a sliding connector of length l = 1.0 m is situated in a uniform magnetic field B = 2T perpendicular to the plane of loop. Resistance of connector is r = 2capital omega. Two resistance of 6capital omega and 3capital omega are connected as shown in figure. The external force required to keep the connector moving with a constant velocity v = 2m/s is

    Physics-General
    General
    Physics-

    Plane figures made of thin wires of resistance R = 50 milli ohm/metre are located in a uniform magnetic field perpendicular into the plane of the figures and which decrease at the rate dB/dt = 0.1 m T/s. Then currents in the inner and outer boundary are. (The inner radius a = 10 cm and outer radius b = 20 cm)

    Plane figures made of thin wires of resistance R = 50 milli ohm/metre are located in a uniform magnetic field perpendicular into the plane of the figures and which decrease at the rate dB/dt = 0.1 m T/s. Then currents in the inner and outer boundary are. (The inner radius a = 10 cm and outer radius b = 20 cm)

    Physics-General
    General
    Physics-

    A highly conducting ring of radius R is perpendicular to and concentric with the axis of a long solenoid as shown in fig. The ring has a narrow gap of width d in its circumference. The solenoid has cross sectional area A and a uniform internal field of magnitude B0. Now beginning at t = 0, the solenoid current is steadily increased to so that the field magnitude at any time t is given by B left parenthesis t right parenthesis equals B subscript 0 end subscript plus alpha t where alpha greater than 0. Assuming that no charge can flow across the gap, the end of ring which has excess of positive charge and the magnitude of induced e.m.f. in the ring are respectively

    A highly conducting ring of radius R is perpendicular to and concentric with the axis of a long solenoid as shown in fig. The ring has a narrow gap of width d in its circumference. The solenoid has cross sectional area A and a uniform internal field of magnitude B0. Now beginning at t = 0, the solenoid current is steadily increased to so that the field magnitude at any time t is given by B left parenthesis t right parenthesis equals B subscript 0 end subscript plus alpha t where alpha greater than 0. Assuming that no charge can flow across the gap, the end of ring which has excess of positive charge and the magnitude of induced e.m.f. in the ring are respectively

    Physics-General
    parallel
    General
    Physics-

    The north and south poles of two identical magnets approach a coil, containing a condenser, with equal speeds from opposite sides. Then

    The north and south poles of two identical magnets approach a coil, containing a condenser, with equal speeds from opposite sides. Then

    Physics-General
    General
    Physics-

    A conducting ring is placed around the core of an electromagnet as shown in fig. When key K is pressed, the ring

    A conducting ring is placed around the core of an electromagnet as shown in fig. When key K is pressed, the ring

    Physics-General
    General
    Physics-

    Shown in the figure is a circular loop of radius r and resistance R. A variable magnetic field of induction B equals B subscript 0 end subscript e to the power of negative t end exponent is established inside the coil. If the key (K) is closed, the electrical power developed right after closing the switch is equal to

    Shown in the figure is a circular loop of radius r and resistance R. A variable magnetic field of induction B equals B subscript 0 end subscript e to the power of negative t end exponent is established inside the coil. If the key (K) is closed, the electrical power developed right after closing the switch is equal to

    Physics-General
    parallel
    General
    Physics-

    The resistance in the following circuit is increased at a particular instant. At this instant the value of resistance is 10capital omega. The current in the circuit will be now

    The resistance in the following circuit is increased at a particular instant. At this instant the value of resistance is 10capital omega. The current in the circuit will be now

    Physics-General
    General
    Physics-

    A conducting rod PQ of length L = 1.0 m is moving with a uniform speed v = 2 m/s in a uniform magnetic field B equals 4.0 T directed into the paper. A capacitor of capacity C = 10 muF is connected as shown in figure. Then

    A conducting rod PQ of length L = 1.0 m is moving with a uniform speed v = 2 m/s in a uniform magnetic field B equals 4.0 T directed into the paper. A capacitor of capacity C = 10 muF is connected as shown in figure. Then

    Physics-General
    General
    Physics-

    A conductor ABOCD moves along its bisector with a velocity of 1 m/s through a perpendicular magnetic field of 1 wb/m2, as shown in fig. If all the four sides are of 1m length each, then the induced emf between points A and D is

    A conductor ABOCD moves along its bisector with a velocity of 1 m/s through a perpendicular magnetic field of 1 wb/m2, as shown in fig. If all the four sides are of 1m length each, then the induced emf between points A and D is

    Physics-General
    parallel
    General
    Physics-

    A square metallic wire loop of side 0.1 m and resistance of 1capital omega is moved with a constant velocity in a magnetic field of 2 wb/m2 as shown in figure. The magnetic field is perpendicular to the plane of the loop, loop is connected to a network of resistances. What should be the velocity of loop so as to have a steady current of 1mA in loop

    A square metallic wire loop of side 0.1 m and resistance of 1capital omega is moved with a constant velocity in a magnetic field of 2 wb/m2 as shown in figure. The magnetic field is perpendicular to the plane of the loop, loop is connected to a network of resistances. What should be the velocity of loop so as to have a steady current of 1mA in loop

    Physics-General
    General
    Physics-

    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 current 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 current in wires AB and CD are

    Physics-General
    General
    Physics-

    A current carrying solenoid is approaching a conducting loop as shown in the figure. The direction of induced current as observed by an observer on the other side of the loop will be

    A current carrying solenoid is approaching a conducting loop as shown in the figure. The direction of induced current as observed by an observer on the other side of the loop will be

    Physics-General
    parallel
    General
    Physics-

    In the following figure, the magnet is moved towards the coil with a speed v and induced emf is e. If magnet and coil recede away from one another each moving with speed v, the induced emf in the coil will be

    In the following figure, the magnet is moved towards the coil with a speed v and induced emf is e. If magnet and coil recede away from one another each moving with speed v, the induced emf in the coil will be

    Physics-General
    General
    Physics-

    As shown in the figure a metal rod makes contact and complete the circuit. The circuit is perpendicular to the magnetic field with B=0.15tesla. If the resistance is 3 capital omega, force needed to move the rod as indicated with a constant speed of 2 m divided by s e c is

    As shown in the figure a metal rod makes contact and complete the circuit. The circuit is perpendicular to the magnetic field with B=0.15tesla. If the resistance is 3 capital omega, force needed to move the rod as indicated with a constant speed of 2 m divided by s e c is

    Physics-General
    General
    Physics-

    A short-circuited coil is placed in a time-varying magnetic field. Electrical power is dissipated due to the current induced in the coil. If the number of turns were to be quadrupled and the wire radius halved, the electrical power dissipated would be

    A short-circuited coil is placed in a time-varying magnetic field. Electrical power is dissipated due to the current induced in the coil. If the number of turns were to be quadrupled and the wire radius halved, the electrical power dissipated would be

    Physics-General
    parallel

    card img

    With Turito Academy.

    card img

    With Turito Foundation.

    card img

    Get an Expert Advice From Turito.

    Turito Academy

    card img

    With Turito Academy.

    Test Prep

    card img

    With Turito Foundation.