An oscillator gives an a.c. output signal without requiring any _____ signal.

An artificial satellite is revolving around the earth without using any fuel. On the other hand an aeroplane requires fuel to fly. Why?

With the help of lebelled circuit diagram, discuss the working of transistor as a common emitter amplifier.Find the phase relationship between input and output signals. Also define its voltage gain.

These questions consist of two statements each,printed as Assertion and Reason.While asnwering these questions you are required to choose any one of the following four responses. Assertion:Volume of blood ejected from the ventricles in one heart beat is called cardiac output. Reason:Cardiac output increases with the increase in body size of organism.

An ac input signal of frequency 60 Hz is rectified by a half wave full wave rectifier. Draw the output waveform and write the output frequency in each case.

Answer the following questions: 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.

Two amplifiers are connected one after the other in series (cascaded).The first amplifier has a voltage gain of 10 and the second has a voltage gain of 20. If the input signal is 0.01 volt, calculate the tput ac signal.

Give reasons for the following observations.Naphthalene balls disappear with time without leaving any solid.

Give reason for the following observations: Naphthalene balls disappear with time without leaving any solid.