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Finding the Direction of Induced emf Using Conservation of Energy

  • 1.

    Determine the direction of induced emf in a coil placed in an increasing magnetic field if the magnetic field is directed out of the page and passes through the coil.

    Answers:

    • The direction of induced emf in the coil will be in an anti-clockwise direction.

    • The direction of induced emf in the coil will be in a clockwise direction.

    • The direction of induced emf cannot be determined.

    • No emf will be induced in the coil as the field is increasing.

  • 2.

    A coil moves toward an increasing magnetic field that is directed upward, calculate, in which direction emf will be induced in the coil.

    Answers:

    • The direction of induced emf cannot be determined.

    • Emf will be induced in a counter-clockwise direction.

    • No emf will be induced in the coil.

    • Emf will be induced in a clockwise direction.

  • 3.

    What will be the direction of induced emf if an increasing magnetic field is directed into the plane and passes over a coil?

    Answers:

    • A counter-clockwise emf will be induced in the coil.

    • A clockwise emf will be induced in the coil.

    • Both clockwise and counter-clockwise emf will be induced.

    • The direction of induced emf cannot be determined.

  • 4.

    A magnetic field increases from {eq}8\ \rm mT {/eq} to {eq}10\ \rm mT {/eq} out of the plane. If this magnetic field is projected on a coil then find the direction of the emf induced in the coil.

    Answers:

    • The coil will have a counter-clockwise induced emf.

    • The coil will have both clockwise and counter-clockwise induced emf.

    • The coil will have a clockwise induced emf.

    • The direction cannot be determined.

  • 5.

    The north pole of a magnet having a decreasing magnetic field is directed into the page passing through a horizontally placed coil. What will be the direction of the emf induced in the coil due to this motion?

    Answers:

    • An anti-clockwise induced emf will be produced in the coil.

    • No emf will be produced.

    • A clockwise induced emf will be produced in the coil.

    • The direction of the induced emf cannot be determined.

  • 6.

    A decreasing magnetic field is directed into the page that passes over a conducting loop. Determine the direction of emf induced in the conducting loop.

    Answers:

    • The direction of emf induced in the conducting loop will be in a clockwise direction.

    • Both clockwise and anticlockwise emf will be induced in the conduction loop.

    • No emf will be induced in the conducting loop.

    • The direction of emf induced in the conducting loop will be in an anti-clockwise direction.

  • 7.

    A magnetic field decrease from {eq}10\ \rm \mu T {/eq} to {eq}6\ \rm \mu T {/eq} towards the plane and passes over a coil. The emf induced in the coil will be equal to which of the following?

    Answers:

    • First, a counter-clockwise emf will be induced, and then a clockwise emf.

    • No emf will be induced in the coil.

    • A counter-clockwise emf will be induced.

    • A clockwise emf will be induced.

  • 8.

    A coil is placed horizontally on a plane. An increasing magnetic field is directed towards the coil in such a way that it appears to be coming out of the plane. Can you predict the direction of the emf induced in the coil?

    Answers:

    • A clockwise emf will be induced in the coil.

    • A counter-clockwise emf will be induced in the coil.

    • A decreasing emf will be induced in the coil.

    • No emf will be induced in the coil.

  • 9.

    Calculate the direction of emf induced in a coil placed in an increasing magnetic field. If the magnetic field is directed into the page and the coil lies horizontally on the plane.

    Answers:

    • Emf will be induced in both clockwise and counter-clockwise directions.

    • A counter-clockwise emf will be induced in the coil.

    • No emf will be induced in the coil.

    • A clockwise emf will be induced in the coil.

  • 10.

    What will be the direction of the emf induced in a coil placed vertically in a decreasing magnetic field if the magnetic field is directed out of the page?

    Answers:

    • The direction of induced emf cannot be determined.

    • The direction of induced emf in the coil will be in a counter-clockwise direction.

    • The direction of induced emf in the coil will have both clockwise and counter-clockwise directions.

    • The direction of induced emf in the coil will be in a clockwise direction.

  • 11.

    A student moves the north pole of a magnet that has an increasing magnetic field toward a hanging coil. If there is a change in the magnetic field due to the movement of the magnet toward the coil, determine in which direction an emf will be induced in the coil.

    Answers:

    • Only a clockwise emf will be induced.

    • Both clockwise and counter-clockwise emf will be induced.

    • No emf will be induced.

    • Only a counter-clockwise emf will be induced.

  • 12.

    In what direction will an emf be induced in a coil placed in an increasing magnetic field and directed out of the page?

    Answers:

    • Both clockwise and counter-clockwise emf will get induced.

    • A clockwise emf will be induced.

    • No emf will get induced.

    • A counter-clockwise emf will be induced.

  • 13.

    In a physics demonstration, a teacher asked a student to determine the direction of induced emf in a coil placed in a changing magnetic field. If the magnetic field increases from {eq}5.5\ \rm \mu T {/eq} to {eq}8.2\ \rm \mu T {/eq} towards the south, then which of the given statements will correctly state the student's answer?

    Answers:

    • The coil will have a counter-clockwise induced emf.

    • The coil will have a clockwise induced emf.

    • The coil will have both clockwise and counter-clockwise induced emf.

    • The direction of induced emf cannot be predicted.

  • 14.

    If a conducting coil is placed in a decreasing magnetic field and directed into the plane, predict the direction of the emf induced in the coil.

    Answers:

    • Both clockwise and counter-clockwise emf are induced in the coil.

    • A clockwise emf is induced in the coil.

    • A counter-clockwise emf is induced in the coil.

    • No emf is induced in the coil.

  • 15.

    A magnetic field is projected over a coil placed on a stand to observe the direction of induced emf. If the magnetic field decreases from {eq}9\ \rm mT {/eq} to {eq}4\ \rm mT {/eq} and the field lines move into the plane then calculate the direction of the induced emf in the coil.

    Answers:

    • No emf is induced in the coil.

    • Clockwise emf is induced in the coil.

    • Counter-clockwise emf is induced in the coil.

    • EMf is induced in the coil but the direction cannot be predicted.

  • 16.

    A magnet with a decreasing magnetic field moves toward a coil at a certain speed. If the south pole of the magnet is oriented toward the coil, in which direction will an emf be induced in the coil?

    Answers:

    • In a clockwise direction.

    • Cannot be determined.

    • Emf will not get induced in the coil.

    • In a counter-clockwise direction.

  • 17.

    If the north pole of a magnet with a decreasing magnetic field moves away from a coil upward, determine which of the following statements correctly relates to the direction of the induced emf in the coil.

    Answers:

    • Emf will get induced, but only in a counter-clockwise direction.

    • Emf will get induced in both clockwise as well as counter-clockwise directions.

    • Emf will not get induced in the coil.

    • Emf will get induced, but only in a clockwise direction.

  • 18.

    A decreasing magnetic field moves toward a coil placed outward from the page, determine which of the following statements correctly refers to the direction of the induced emf in the coil.

    Answers:

    • Emf will never get induced in the coil.

    • Emf will get induced in the coil but we cannot predict the direction.

    • Only clockwise emf will get induced in the coil.

    • Only counter-clockwise emf will get induced in the coil.

  • 19.

    A decreasing magnetic field directed inward in the plane passes over a coil. Predict the direction in which emf will be induced in the coil.

    Answers:

    • Only clockwise emf will get induced in the coil.

    • Only counter-clockwise emf will get induced in the coil.

    • As the magnet is stationary, emf will not get induced in the coil.

    • The induced emf's direction cannot be predicted.

  • 20.

    Daisy places a circular conductor in an increasing magnetic field. If the field is directed into the plane then which of the given statements is correct regarding Daisy's observation of induced emf.

    Answers:

    • No emf will get induced in the circular conductor as the field is increasing.

    • A clockwise emf will get induced in the circular conductor.

    • Both clockwise and counter-clockwise emf will get induced in the circular conductor.

    • A counter-clockwise emf will get induced in the circular conductor.

  • 21.

    Find the direction of induced emf in a coil placed in a decreasing magnetic field. If the magnetic field is directed out of the page and passes through the coil lying horizontally.

    Answers:

    • The coil will have an anti-clockwise induced emf.

    • The direction of induced emf cannot be predicted.

    • The coil will have a clockwise induced emf.

    • The coil won't have any induced emf.

  • 22.

    If a coil is moved toward the south pole of a magnet with an increasing magnetic field, in which direction will emf be induced in the coil?

    Answers:

    • Predicting the direction of induced emf is not possible.

    • Anti-clockwise emf will be induced in the coil.

    • No emf will be induced in the coil.

    • Clockwise emf will be induced in the coil.

  • 23.

    Predict the direction of induced emf, if an increasing magnetic field is directed into the plane and passes over a coil?

    Answers:

    • Both clockwise and counter-clockwise emf will be induced in the coil.

    • A counter-clockwise induced emf will be generated in the coil.

    • The direction of induced emf cannot be predicted.

    • A clockwise induced emf will be generated in the coil.

  • 24.

    A changing magnetic field increases from {eq}2\ \rm mT {/eq} to {eq}5\ \rm mT {/eq} into the page. Determine the direction of induced emf if this magnetic field is projected on a coil placed vertically.

    Answers:

    • The coil will have no induced emf.

    • Predicting the direction of induced emf is not possible.

    • A clockwise emf will be induced in the coil,

    • A counter-clockwise emf will be induced in the coil.

  • 25.

    The north pole of a magnet with an increasing magnetic field moves toward a horizontally placed coil. Predict the direction of the induced emf produced in the coil due to this motion.

    Answers:

    • Clockwise emf will be induced in the coil.

    • There will be no induced emf in the coil.

    • Predicting the direction of induced emf is not possible.

    • Counter-clockwise emf will be induced in the coil.

  • 26.

    An increasing magnetic field is projected out of the page that passes over a conducting loop. Determine the direction of emf induced in the conducting loop.

    Answers:

    • Both clockwise and counter-clockwise emf will get induced in the conducting loop.

    • A counter-clockwise emf will get induced in the conducting loop.

    • A clockwise emf will get induced in the conducting loop.

    • No emf will be induced in the conducting loop.

  • 27.

    A magnetic field increases from {eq}3\ \rm \mu T {/eq} to {eq}6\ \rm \mu T {/eq} upward and passes over a conductor in the form of a coil. The direction of emf induced in the coil will be equal to which of the following?

    Answers:

    • The direction of emf induced in the coil will be in a counter-clockwise direction.

    • The direction of emf cannot be determined.

    • The direction of emf induced in the coil will be in a clockwise direction.

    • No emf will be induced in the coil.

  • 28.

    A coil is placed horizontally on a table and a magnetic field is directed towards the coil in such a way that it appears to be coming out of the plane. Can you predict the direction of the emf induced in the coil if the magnetic field is a decreasing one?

    Answers:

    • Both clockwise and counter-clockwise induced emf.

    • A clockwise induced emf.

    • Cannot predict the direction of induced emf.

    • A counter-clockwise induced emf.

  • 29.

    Determine the direction of emf induced in a coil placed in a decreasing magnetic field. If the magnetic field is directed into the page and the coil lies horizontally on the plane.

    Answers:

    • The direction of induced emf cannot be predicted.

    • Emf will be induced in both clockwise and counter-clockwise directions.

    • Emf will be induced in a clockwise direction.

    • Emf will be induced in a counter-clockwise direction.

  • 30.

    What will be the direction of the induced emf in a coil placed vertically in the north direction, if an increasing magnetic field moves toward the coil?

    Answers:

    • A clockwise emf will get induced.

    • The direction of induced emf cannot be determined.

    • A counter-clockwise emf will be induced.

    • Emf will not get induced in the coil.

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