Electromagnetic Induction And Alternating Current Book Back Practice

12th Standard Physics — Electromagnetic Induction And Alternating Current: Book Back 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

An electron moves on a straight line path XY as shown in the figure. The coil abcd is adjacent to the path of the electron. What will be the direction of current, if any, induced in the coil?

An electron moves along a straight line XY near a rectangular conducting loop abcd.

A.The current will reverse its direction as the electron goes past the coil B.No current will be induced C.abcd D.adcb

A thin semi-circular conducting ring (PQR) of radius r is falling with its plane vertical in a horizontal magnetic field B, as shown in the figure. The potential difference developed across the ring when its speed v, is

A semicircular conducting loop PQR falls through a uniform horizontal magnetic field B.

A.Zero B.\(B \pi rv^2/2\) and P is at higher potential C.\(\pi rBv\) and R is at higher potential D.\(2rBv\) and R is at higher potential

The flux linked with a coil at any instant t is given by \(\Phi_B = 10t^2 - 50t + 250\). The induced emf at t = 3 s is

A.-190 V B.-10 V C.10 V D.190 V

When the current changes from +2A to -2A in 0.05 s, an emf of 8 V is induced in a coil. The co-efficient of self-induction of the coil is

A.0.2 H B.0.4 H C.0.8 H D.0.1 H

The current i flowing in a coil varies with time as shown in the figure. The variation of induced emf with time would be

A primary graph showing current variation with time and four optional graphs showing the resulting induced emf.

A.A

B.B

C.C

D.D

A circular coil with a cross-sectional area of 4 cm\(^2\) has 10 turns. It is placed at the centre of a long solenoid that has 15 turns/cm and a cross-sectional area of 10 cm\(^2\). The axis of the coil coincides with the axis of the solenoid. What is their mutual inductance?

A.7.54 \(\mu\)H B.8.54 \(\mu\)H C.9.54 \(\mu\)H D.10.54 \(\mu\)H

In a transformer, the number of turns in the primary and the secondary are 410 and 1230 respectively. If the current in primary is 6A, then that in the secondary coil is

A.2 A B.18 A C.12 A D.1 A

A step-down transformer reduces the supply voltage from 220 V to 11 V and increase the current from 6 A to 100 A. Then its efficiency is

A.1.2 B.0.83 C.0.12 D.0.9

In an electrical circuit, R, L, C and AC voltage source are all connected in series. When L is removed from the circuit, the phase difference between the voltage and current in the circuit is \(\pi/3\). Instead, if C is removed from the circuit, the phase difference is again \(\pi/3\). The power factor of the circuit is

A.1/2 B.\(1/\sqrt{2}\) C.1 D.\(\sqrt{3}/2\)

Q10

In a series RL circuit, the resistance and inductive reactance are the same. Then the phase difference between the voltage and current in the circuit is

A.\(\pi/4\) B.\(\pi/2\) C.\(\pi/6\) D.zero

Q11

In a series resonant RLC circuit, the voltage across 100 \(\Omega\) resistor is 40 V. The resonant frequency \(\omega\) is 250 rad/s. If the value of C is 4 \(\mu\)F, then the voltage across L is

A.600 V B.4000 V C.400 V D.1 V

Q12

An inductor 20 mH, a capacitor 50 \(\mu\)F and a resistor 40 \(\Omega\) are connected in series across a source of emf V = 10 sin 340 t. The power loss in AC circuit is

A.0.76 W B.0.89 W C.0.46 W D.0.67 W

Q13

The instantaneous values of alternating current and voltage in a circuit are \(i = \frac{1}{\sqrt{2}} \sin(100\pi t)\) A and \(v = \frac{1}{\sqrt{2}} \sin(100\pi t + \pi/3)\) V. The average power in watts consumed in the circuit is

A.1/4 B.3/4 C.1/2 D.1/8

Q14

In an oscillating LC circuit, the maximum charge on the capacitor is Q. The charge on the capacitor when the energy is stored equally between the electric and magnetic fields is

A.\(Q/2\) B.\(Q/\sqrt{3}\) C.\(Q/\sqrt{2}\) D.Q

Q15

\(\frac{20}{\pi^2}\) H inductor is connected to a capacitor of capacitance C. The value of C in order to impart maximum power at 50 Hz is

A.50 \(\mu\)F B.0.5 \(\mu\)F C.500 \(\mu\)F D.5 \(\mu\)F

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