During the positive half cycle of the supply, diodes D1 and D2 conduct are forward biased and conduct current while diodes D3 and D4 are reverse biased and they act as an open circuit, the current flows through the load.
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)