Transistors

The voltage gain in a common emitter transistor can be related to the current gain through the following relation: \bigskip Step 1: The voltage gain is given as 160, and the change in the base current is . The change in the output current is therefore: Thus, the correct answer is . \bigskip

Step 1: Understanding Orbital Energy Comparisons
- The energy levels of hydrogen-like atoms depend on the principal quantum number and nuclear charge.
- For hydrogen ( ), energy levels follow:
- For helium ( ), the energy levels are modified by the nuclear charge : Step 2: Evaluating the Given Statements
- (I) : This is trivially true.
- (II) : Incorrect, as energy levels differ for different atomic numbers.
- (III) : Incorrect, as higher nuclear charge in causes lower energy.
- (IV) : True, since helium has a stronger nuclear charge, lowering energy levels. Thus, the correct answer is I, IV only.

Step 1: The power gain is related to the current gain and the resistances and by the formula: Substituting the given values: Thus, the current gain is 80.

In a common emitter amplifier, the voltage gain ( ) is given by: Where: - Current gain = 45
- (collector resistance)
- (base resistance)
Now, substituting the values: Thus, the voltage gain of the amplifier is 225.