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Electromagnetic Induction and Alternating Currents

Each subtopic includes About section, revision page link, 10 preview questions, and practice CTAs.

Faraday's Laws and Lenz's Law

Subtopic

Faraday's Laws and Lenz's Law under Electromagnetic Induction and Alternating Currents for Grade 12 ICSE.

About Topic & Revision

Preview questions (no answers)

  1. 1.

    A bar magnet is moved toward a stationary metallic loop with its North Pole facing the loop. What is the direction of the induced current when viewed from the side of the magnet?

    A.

    Anticlockwise

    B.

    Clockwise

    C.

    No current is induced

    D.

    Alternating between clockwise and anticlockwise

  2. 2.

    According to Faraday's Second Law of Electromagnetic Induction, the magnitude of the induced EMF in a conductor is:

    A.

    Inversely proportional to the magnetic flux linked with it

    B.

    Directly proportional to the magnetic flux linked with it

    C.

    Inversely proportional to the rate of change of magnetic flux

    D.

    Directly proportional to the rate of change of magnetic flux

  3. 3.

    Lenz's Law is a direct consequence of the Law of Conservation of:

    A.

    Mass

    B.

    Energy

    C.

    Charge

    D.

    Linear Momentum

Download the worksheet for Electromagnetic Induction and Alternating Currents - Faraday's Laws and Lenz's Law to practice offline. It includes additional chapter-level practice questions.

Self and Mutual Induction

Subtopic

Self and Mutual Induction under Electromagnetic Induction and Alternating Currents for Grade 12 ICSE.

About Topic & Revision

Preview questions (no answers)

  1. 1.

    The diagram below represents the process where a changing current in one coil induces an electromotive force (EMF) in a neighboring coil. What is this phenomenon called?

    A.

    Self-induction

    B.

    Eddy currents

    C.

    Mutual induction

    D.

    Hysteresis

  2. 2.

    The magnetic flux Φ\Phi linked with a coil is proportional to the current II flowing through it. What is the constant of proportionality LL called?

    A.

    Mutual Inductance

    B.

    Self-Inductance

    C.

    Capacitance

    D.

    Resistance

  3. 3.

    The induced emf ee in a coil of self-inductance LL when the current II changes with time tt is given by which formula?

    A.

    e=−LdIdte = -L \frac{dI}{dt}

    B.

    e=−LIe = -L I

    C.

    e=−1LdIdte = -\frac{1}{L} \frac{dI}{dt}

    D.

    e=−L2dIdte = -L^2 \frac{dI}{dt}

Download the worksheet for Electromagnetic Induction and Alternating Currents - Self and Mutual Induction to practice offline. It includes additional chapter-level practice questions.

Alternating Current (LCR Circuits, Resonance)

Subtopic

Alternating Current (LCR Circuits, Resonance) under Electromagnetic Induction and Alternating Currents for Grade 12 ICSE.

About Topic & Revision

Preview questions (no answers)

  1. 1.

    The average power dissipated in a purely capacitive AC circuit over one complete cycle is:

    A.

    12CV2\frac{1}{2}CV^2

    B.

    VIVI

    C.

    V2/XCV^2/X_C

    D.

    Zero

  2. 2.

    In a series LCRLCR circuit, electrical resonance occurs when which of the following conditions is satisfied?

    A.

    Inductive reactance is equal to capacitive reactance

    B.

    Resistance is equal to inductive reactance

    C.

    Inductive reactance is zero

    D.

    Capacitive reactance is zero

  3. 3.

    What is the phase difference between the voltage and the current in a circuit containing only a pure inductor?

    A.

    Current leads voltage by π/2\pi/2

    B.

    Voltage and current are in phase

    C.

    Voltage leads current by π/2\pi/2

    D.

    Voltage leads current by π\pi

Download the worksheet for Electromagnetic Induction and Alternating Currents - Alternating Current (LCR Circuits, Resonance) to practice offline. It includes additional chapter-level practice questions.

Transformers and AC Generators

Subtopic

Transformers and AC Generators under Electromagnetic Induction and Alternating Currents for Grade 12 ICSE.

About Topic & Revision

Preview questions (no answers)

  1. 1.

    The core of a transformer is laminated to reduce the effect of:

    A.

    Copper losses

    B.

    Hysteresis loss

    C.

    Eddy currents

    D.

    Flux leakage

  2. 2.

    What is the primary function of the slip rings in an AC generator?

    A.

    To convert AC into DC

    B.

    To reduce the resistance of the armature

    C.

    To provide a continuous connection between the rotating coil and the external circuit

    D.

    To increase the strength of the magnetic field

  3. 3.

    In a step-down transformer, the number of turns in the primary coil (NpN_p) and secondary coil (NsN_s) are related as:

    A.

    Np>NsN_p > N_s

    B.

    Np<NsN_p < N_s

    C.

    Np=NsN_p = N_s

    D.

    Np×Ns=1N_p \times N_s = 1

Download the worksheet for Electromagnetic Induction and Alternating Currents - Transformers and AC Generators to practice offline. It includes additional chapter-level practice questions.

Electromagnetic Induction and Alternating Currents - Class 12 Physics (ICSE) | Krit.club