What is the Boolean equation for the logic represented by the relay circuit diagram of the drilling machine?

In circuits involving relays, the logical operations typically mirror the functions of the relays themselves, often using AND and OR operations to represent how different buttons or inputs trigger the system.

When analyzing the given choices, the correct option indicates a logical expression where all inputs are combined using the AND operation. This signifies that for the relay circuit to be activated, all conditions specified must be satisfied simultaneously. In this case, the inputs PB1, PB2, and B1 are all required to be active (or 'true') to drive the output M : K1 high, which represents the condition for the relay to engage.

Using the AND operation indicates that the circuit requires all buttons (PB1 and PB2) along with the condition B1 to be engaged for the desired operation of the drilling machine. This aligns with typical functionality in relay circuits where multiple conditions must coexist for a complete signal to be transmitted.

In contrast, alternatives might suggest a combination of inputs with different logical operations (like OR). However, these would imply a lesser requirement for activation of the relay, which does not accurately reflect the circuit behavior indicated by the question. The correct answer retains the integrity of relay logic, ensuring all components must be active for the defined outcome.