The correct Answer is Rheostat
Explanation
The question pertains to components used in electrical circuits for specific functions, particularly current regulation without affecting source voltage. Understanding the function of each component is crucial.
Statement-wise Analysis
Rectifier
- Incorrect. A rectifier is an electrical device that converts alternating current (AC) to direct current (DC) by allowing current to flow in only one direction. It does not primarily regulate current without altering the source voltage in the manner described.
Rheostat
- Correct. A rheostat is a variable resistor used to control current by varying the resistance in an electrical circuit. By changing the resistance, the current flowing through the circuit can be increased or decreased according to Ohm's Law (I = V/R), without directly altering the source voltage.
Inductor
- Incorrect. An inductor is a passive two-terminal electrical component that stores energy in a magnetic field when electric current flows through it. It opposes changes in current, but its primary function is not to regulate current without altering the source voltage in a steady-state DC circuit or as a primary current regulator in the sense of a rheostat.
Transformer
- Incorrect. A transformer is an electrical device that transfers electrical energy between two or more circuits through electromagnetic induction. It is primarily used to step up or step down AC voltages and currents, but it does not regulate current without altering the source voltage in the manner described for a rheostat.
Key Takeaway: A rheostat is a variable resistor specifically designed to regulate current in a circuit by changing its resistance, thereby controlling current flow without directly modifying the source voltage.