Question

Torque and armature current characteristics are known as ________ characteristics. (Electrical Mechanical)

Hint:

To quickly classify characteristics: if the horizontal axis represents an electrical value like current ($I_a$), the curve is an electrical characteristic. If both axes plot mechanical parameters (like speed $N$ and torque $T$), the curve is a mechanical characteristic.

Answer 1

Step 1: Classifying Motor Characteristic Curves:
Engineers study three fundamental characteristic curves to analyze DC motor performance:

• Torque vs. Armature Current ($T$ vs. $I_a$)
• Speed vs. Armature Current ($N$ vs. $I_a$)
• Speed vs. Torque ($N$ vs. $T$)

Step 2: Defining Electrical vs. Mechanical Characteristics:

• Electrical Characteristics: Curves that relate mechanical output parameters (such as torque $T$ or speed $N$) directly to electrical input variables (such as the armature current $I_a$). Thus, the $T$ vs. $I_a$ curve is classified as an Electrical Characteristic.
• Mechanical Characteristics: Curves that relate mechanical variables to each other (specifically speed $N$ vs. torque $T$) without involving electrical variables.

Step 3: Conclusion:
The torque and armature current ($T\text{--}I_a$) relationship is classified as an Electrical characteristic.