Final answer:
The correct answer is a. Work is positive and the electrode is negative, known as straight polarity or direct current electrode negative (DCEN) in welding. This polarity affects various aspects of the welding process, similar to how electric fields and charges behave in other contexts within Physics.
Step-by-step explanation:
Straight polarity in welding refers to the polarity of the electrical current used during the welding process. The correct answer to your question is: a. Work is positive and the electrode is negative. This means that the workpiece is connected to the positive terminal of the power source and the electrode is connected to the negative terminal, which is also known as direct current electrode negative (DCEN). The polarity has significant effects on the welding process, including penetration, deposition rate, and bead shape. For example, the direction of the electric field of a negative charge is inward. This is similar to how negative charges, like electrons, are attracted to a positive terminal in a battery or positive plate in a capacitor. The concept is applied in different scenarios, such as the flow of electrons in a circuit or the charging and discharging of plates in a capacitor where a battery does the work to separate positive and negative charges.