When a shaft is subjected to combined twisting moment (T) and bending moment (M), then the equivalent twisting moment is equal to

• A. <img src="/_files/images/mechanical-engineering/machine-design/578-262-1.png">
• B. <img src="/_files/images/mechanical-engineering/machine-design/578-262-2.png">
• C. <img src="/_files/images/mechanical-engineering/machine-design/578-262-3.png">
• D. <img src="/_files/images/mechanical-engineering/machine-design/578-262-4.png">