Final answer:
The device known as a thermocouple uses dissimilar metals to control electron flow, while resistors dissipate power as heat and capacitors temporarily store charge. Inductors provide self-inductance to a circuit, and ohmic devices like resistors have a linear voltage-current relationship.
Step-by-step explanation:
A device that uses dissimilar metals to control electron flow is known as a thermocouple (option c). The other options listed - resistor, capacitor, and inductor, have different functions in electrical circuits:
- Resistor - A component that resists the flow of current and dissipates power in the form of heat (option d from 'Check your Understanding').
- Capacitor - A device used to store charge temporarily and does not dissipate power.
- Inductor - A circuit element used to provide self-inductance, usually represented by a symbol resembling a coil of wire.
An ohmic device, such as a resistor, exhibits a linear relationship between the voltage and the current. In contrast, a nonohmic device like a diode does not have this linear relationship and allows current to flow only in one direction. Finally, electrochemical cells such as galvanic cells are devices that facilitate redox reactions and electron transfer through an external circuit.