HSC Science (Electronics) 12th Standard Board Exam - Maharashtra State Board Question Bank Solutions

In a series LCR circuit at resonance, the applied emf and current are - ______ 

A series LCR resonant circuit is used as ______

A parallel LC resonant circuit is used as ______ 

In the LCR series circuit, what is the condition for current resonance? 

State any one characteristic of a parallel LC AC resonance circuit.

State any two characteristics of a series LCR AC resonance circuit.

In the LCR series circuit, what are the (a) impedance and (b) reactance at current resonance? 

A coil of resistance 10 Ω and inductance 100mH and a capacitor of variable capacitance are connected across a 20V, 50Hz A.C. supply. At what capacitance will resonance occur?

Obtain the expression for the resonant frequency of the LCR series circuit and explain electrical resonance in an LCR series circuit.

Calculate the current flowing through two long parallel wires carrying equal currents and separated by a distance of 1.35 cm experiencing a force per unit length of 4.76 × 10^-2 N/m.

An electric lamp connected in series with a capacitor and an AC source glows with a certain brightness. (a) How does the average power change on increasing the capacitance? (b) How does the brightness of the lamp change on increasing the capacitance?

An air-cored solenoid, 40 cm long and of cross-sectional area 5 cm², is tightly wound with 400 turns of copper wire and carries a steady current of 10 A. (a) Calculate the self-inductance of the solenoid. (b) Find the emf induced if the current in the solenoid decreases to zero in 0.2 s.

State the factors on which the magnetic coupling coefficient of two coils depends.

With a neat diagram briefly describe the function of an open tube manometer.

What is an acceptor circuit?

State the use of the acceptor circuit.

A coil of resistance 5 Ω and self inductance 0.2 H is connected in series with variable capacitor across a 30 V_(rms), 50 Hz supply. (i) At what capacitance resonance occur? (ii) Find the corresponding current.

Obtain an expression for the self inductance of a solenoid.

State the expression for the force per unit length between two infinitely long parallel conductors carrying current and hence define the SI unit of current.

Electrostatic energy of 4 x 10⁻⁴ J is stored in a charged 25 pF capacitor. Find the charge on the capacitor.