Consider an amplifier circuit using a transistor.The output power is several times greater than the input power.Where does the extra power come from?

Power Gain of CE amplifier circuit is given by

A load resistor of 2 k Omega is connected in the collector branch of an amplifier circuit using a transistor in common-emitter mode.The current gain beta-50 .The input resistance of the transistor is 0.50 k Omega . If the input current is changed by 50 mu A ,(a)by what amount soes the output voltage change by ,(b)by what amount does the input voltage change and (c) what is the power gain ?

The output power in step-up transformer used in practice is

In a common emitter amplifier circuit using an n-p-n transistor, the phase difference between the input and the output voltages will be:-

Consider four circuits shown in the figure below. In which circuit power dissipated is greatest (Neglect the internal resistance of the power supply)?

In the given electric circuit find (a) current (b) power output (c) relation between r and R so that the electric power output (that means power to R) is maximum. (d) value of maximum power output (e) plot graph between power and resistance of load (f) from graph we see that for a given power output there exixts two values of external resistance, prove that the product of these resistances equal to r^2 . (g) what is the efficiency of the cell when it is used to supply maximum power.

The resolving power of electron microscope is____times greater than that of a light microscope.

In a common emitter amplifier , the load resistance of the output circuit is 500 times the resistance of the input circuit. If alpha = 0.98 , then find the voltage gain and power gain .

For an ideal transformer ratio of output ot the input power is always