Science (English Medium) Class 12 - CBSE Question Bank Solutions

Obtain if the circuit is connected to a high-frequency supply (240 V, 10 kHz). Hence, explain the statement that at very high frequency, an inductor in a circuit nearly amounts to an open circuit. How does an inductor behave in a dc circuit after the steady state?

A 100 µF capacitor in series with a 40 Ω resistance is connected to a 110 V, 60 Hz supply.

(a) What is the maximum current in the circuit?

(b) What is the time lag between the current maximum and the voltage maximum?

Obtain if the circuit is connected to a 110 V, 12 kHz supply? Hence, explain the statement that a capacitor is a conductor at very high frequencies. Compare this behaviour with that of a capacitor in a dc circuit after the steady state.

An applied voltage signal consists of a superposition of a dc voltage and an ac voltage of high frequency. The circuit consists of an inductor and a capacitor in series. Show that the dc signal will appear across C and the ac signal across L.

Magnetic intensity is given by ______.

If `vec"H"` = magnetic intensity, `chi` = susceptibility, magnetic moment per unit volume `vec"M"` equals ______.

Alternating current is so called because _______.

In a circuit containing resistance only, voltage and current are ______.

Average power supplied to an inductor over one complete cycle is ______.

If circuit containing inductance only, the current ______.

Photoelectric effect is ______.

The difference in mass of a nucleus and its constituents is called ______.

In a pure or intrinsic semiconductor, valence band holes and conduction-band electrons are always ______.

Magnetic lines of force due to a bar magnet do not intersect because ______.

A magnetic needle of magnetic moment 6.7 × 10^–2 Am² and moment of inertia 7.5 × 10^–6 kg m² is performing simple harmonic oscillations in a magnetic field of 0.01 T. Time taken for 10 complete oscillations is ______.

One can define ...A... of a place as the vertical plane which passes through the imaginary line joining the magnetic North and the South–poles. Here, A refers to ______.