A force of $$400$$ $$N$$ is applied to the brake drum of $$0.5$$ $$m$$ diameter in a band-brake system as shown in the figure, where the wrapping angle is $${180^ \circ }$$ . If the coefficient of friction between the drum and the band is $$0.25,$$ the braking torque applied, in $$N.m$$ is

A fillet welded joint is subjected to transverse loading F as shown in the figure. Both legs of the fillets are of $$10$$ $$mm$$ size and the weld length is $$30$$ $$mm.$$ If the allowable shear stress of the weld is $$94$$ $$MPa,$$ considering the minimum throat area of the weld, the maximum allowable transverse load in $$kN$$ is

A solid cylinder of diameter $$100$$ $$mm$$ and height $$50$$ $$mm$$ is forged between two frictionless flat dies to a height of $$25$$ $$mm.$$ The percentage change in diameter is

In a $$DC$$ $$arc$$ welding operating, the length characteristic was obtained as $${V_{arc}} = 20 + 5l$$ where the $$arc$$ length $$l$$ was varied between $$5mm$$ and $$7mm.$$ Here $${V_{arc}}$$ denotes the arc voltage in volts. The $$arc$$ current was varied from $$400A$$ to $$500A.$$ Assuming linear power source characteristic, the open circuit voltage and the short circuit current for the welding operation are