Electromagnetic Induction And Alternating Current Additional Practice

12th Standard Physics — Electromagnetic Induction And Alternating Current: Additional Online Practice Test

Pick how many questions you want and set a time limit, then start. You'll get your score at the end with the correct answer and an explanation for every question. Free, in Tamil and English — 15 questions available.

Set up your test

Number of questions

Time limit

Time remaining00:00

A rectangular loop of area A is placed in a uniform magnetic field B. If the angle between the magnetic field direction and the plane of the loop is 30 degrees, what is the magnetic flux linked with the loop?

A.BA B.BA / 2 C.(sqrt(3) * BA) / 2 D.Zero

According to Lenz's law, the induced current in a circuit always flows in a direction such that its own magnetic field opposes:

A.the existing magnetic flux B.the external magnetic field C.the change in magnetic flux D.the electromotive force

To minimize power loss due to eddy currents in the core of a transformer, the core is typically:

A.made of a single solid block of soft iron B.constructed from thin, insulated laminations C.cooled to cryogenic temperatures D.made of a non-magnetic material

The self-inductance of a long solenoid of length l, area A, and total number of turns N in vacuum is given by:

A.(mu_0 * N^2 * A) / l B.mu_0 * N * A * l C.(mu_0 * N * A) / l D.mu_0 * N^2 * A * l

Two neighboring coils have a mutual inductance of 2 H. If the current in the first coil changes at a constant rate of 5 A/s, the magnitude of the induced emf in the second coil is:

A.2.5 V B.5 V C.10 V D.20 V

A metal rod of length L moves with a constant velocity v perpendicular to a uniform magnetic field B. The induced motional emf across its ends is:

A.BLv B.0.5 * BLv C.BLv^2 D.B^2Lv

In a single-phase AC generator, the induced emf is at its maximum value when the plane of the rotating coil is:

A.perpendicular to the magnetic field lines B.parallel to the magnetic field lines C.inclined at 45 degrees to the field lines D.stationary within the field

In an ideal step-up transformer, which of the following is true when comparing the secondary to the primary?

A.The secondary voltage is higher and current is higher B.The secondary voltage is lower and current is lower C.The secondary voltage is higher and current is lower D.The secondary voltage is lower and current is higher

The root mean square (RMS) value of a sinusoidal alternating current with a peak value Im is:

A.Im / 2 B.Im / sqrt(2) C.sqrt(2) * Im D.2 * Im

Q10

In an AC circuit consisting of a pure inductor, the current:

A.leads the voltage by 90 degrees B.lags the voltage by 90 degrees C.is in phase with the voltage D.leads the voltage by 180 degrees

Q11

If the frequency of the AC source in a purely capacitive circuit is tripled, the capacitive reactance Xc becomes:

A.three times its original value B.nine times its original value C.one-third of its original value D.unchanged

Q12

In a series RLC circuit, electrical resonance occurs when the frequency of the source is such that:

A.The resistance is zero B.Inductive reactance is equal to capacitive reactance C.The impedance is at its maximum value D.The current is at its minimum value

Q13

The power factor of an AC circuit is defined as the cosine of the phase angle between voltage and current. In a series RLC circuit, it is equal to the ratio of:

A.Resistance to Impedance (R/Z) B.Reactance to Resistance (X/R) C.Voltage to Current (V/I) D.Inductance to Capacitance (L/C)

Q14

What is the expression for the natural angular frequency of free oscillations in an LC circuit?

A.sqrt(L * C) B.L * C C.1 / sqrt(L * C) D.1 / (L * C)

Q15

A 'wattless current' occurs in an AC circuit when the phase difference between voltage and current is:

A.0 degrees B.45 degrees C.90 degrees D.180 degrees

More for this chapter

About this Electromagnetic Induction And Alternating Current test

This free online practice test covers Electromagnetic Induction And Alternating Current from the 12th Standard Physics (Samacheer Kalvi) syllabus. Choose the number of questions and an optional time limit, then answer and submit — everything is checked in your browser, with the correct answers and a worked explanation shown at the end. For the full solutions to every question in this set, see the solved MCQs page.

More chapters in Physics

View all