By the term, torque is meant the turning or twisting moment of a force about an axis. It is measured by the product of the force and the radius at which this force acts. Consider a pulley of radius r meter acted upon by a circumferential force of F Newton which causes it to rotate at N r.p.m. The angular speed of the pulley is ω = 2πN/60 rad/sec Work is done by this force in one revolution = Force × distance = F × 2πR Joule The power developed = Work Done/Time = (F × 2πR)/60/N = (F × R) × (2πN)/60 The power developed = T × ω watt or P = T ω Watt pmech = (ωT)
According to the Norton theorem, to find the Norton current, first remove the load resistance RL from the network terminals AB. Short circuit the terminals AB as shown in Figure calculate the current ISc or IN through the short circuit. Now resistance of 150Ω will not show any effect in the circuit. So only resistance of 30Ω will be effective. Norton current IN = 360/30 IN = 12 A
Given Inductance L = 2 H Rate of change of current di/dt = 5 A/sec Self induced EMF = − (Rate of change of current × Inductance) = −L(di/dt) = −(5 × 2) = −10V
Galvanized steel conductors do not corrode, and possess high resistance. Hence such Wires are used in telecommunications circuits, earth wires, guard wire, stray wire, etc.
EXAMIANS
