If J is moment of Inertia, D is damping constant, C is spring constant, G is displacement constant and I is current throught the coil of DArsonval galvanometer, the equation of motion is

• A. <img src="/_files/images/electronics-and-communication-engineering/measurements-and-instrumentation/232-66-1.png">
• B. <img src="/_files/images/electronics-and-communication-engineering/measurements-and-instrumentation/232-66-2.png">
• C. <img src="/_files/images/electronics-and-communication-engineering/measurements-and-instrumentation/232-66-3.png">
• D. <img src="/_files/images/electronics-and-communication-engineering/measurements-and-instrumentation/232-66-4.png">