How does the sign of the phase angle `phi`, by which the supply voltage leads the current in an LCR series circuit, change as the supply frequency is gradually increased from very low to very high values?

How do the energy gaps between successive electron energy levels in an atom very from low to high n values ?

A coil of inductance 0.50 H and resistance 100 ohm is connected to a high frequency supply (240 V, 10 kHz). (a) Obtain the maximum current in the coil. (b) what is the time lag between voltage maximum and the current maximum. 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 low voltage supply from which one needs high currents must have very low internal resistance. Why?

Read the given passage and answers following questions : A catalytic process in which the catalyst and the reactants are present in different phases is known as a heterogeneous catalysis. This heterogeneous catalytic action can be explained in terms of the adsorption theory. The mechanism of catalysis involves the following steps: (i) Adsorption of reactant molecules on the catalyst surface. (ii) Occurrence of a chemical reaction through the formation of an intermediate. (iii) De-sorption of products from the catalyst surface (iv) Diffusion of products away from the catalyst surface. In this process, the reactants are usually present in the gaseous state and the catalyst is present in the solid state. Gaseous molecules are then adsorbed on the surface of the catalyst. As the concentration of reactants on the surface of the catalyst increases, the rate of reaction also increases. In such reactions, the products have very less affinity for the catalyst and are quickly desorbed, thereby making the surface free for other reactants. How many steps involved in mechanism of catalysis ?

When an inductor L and resistor R in series are connected across a 12 volts 50 Hertz supply a current of 0.5 ampere flows in thecircuit the circuit current differs in phase from applied voltage by pi/3 Calculate the value R.

A 100 micro F capacitor in series with a 40 ohm resistance is connected to a 110 V, 12 kHz supply? (a) What is the maximum current in the circuit? (b) What is time lag between the current maximum and voltage maximum? 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.

When a series combination of inductance and resistance are conneted with a 10 V, 50 Hz a.c. source, a current of 1 A flows in the circuit. The voltage leads the current by a phase angle of pi//3 radian. Calculate the values of resistance and inductance.

A series LCR circuit is connected to a source having voltage v=v_(m) sin omegat .Derive the expression for the instantaneous current I and its phase relationship to the applied voltage. Obtain the condition for resonance to occur.Define 'power factor'.State the conditions under which it is maximum