The rate of working of an engine is given by
`R = 15v + (6000)/(v), " where " 0 lt v lt 30`
and v is the speed of the engine. Show that R is the least when v = 20

The ptich of the whistle of an engine appears to rise to 1,2 times the original value when it approaches a stationary observer. Calculate the speed of the engine if the speed of sound in air is 330 m/s. v'=((V)/(V-V_(S)))v

The ptich of the whistle of an engine appears to rise to 1,2 times the original value when it approaches a stationary observer. Calculate the speed of the engine if the speed of sound in air is 330 m/s. v'=((V)/(V-V_(S)))v

A source of sound emits sound waves at frequency f_(0) . It is moving towards an observer with fixed speed v_(s)(v_(s) lt v where v is the speed in air). If the observer were to move towards the source with speed v_(0) one of the following two graphs (A and B) will give the correct variation of the frequency f heard by the observer as v_(0) is changed, The variation of f with v_(0) is given correctly by :-

A source of sound emits sound waves at frequency f_(0) . It is moving towards an observer with fixed speed v_(s)(v_(s) lt v where v is the speed in air). If the observer were to move towards the source with speed v_(0) one of the following two graphs (A and B) will give the correct variation of the frequency f heard by the observer as v_(0) is changed, The variation of f with v_(0) is given correctly by :-

A source of sound emits sound waves at frequency f_(0) . It is moving towards an observer with fixed speed v_(s)(v_(s) lt v where v is the speed in air). If the observer were to move towards the source with speed v_(0) one of the following two graphs (A and B) will give the correct variation of the frequency f heard by the observer as v_(0) is changed, The variation of f with v_(0) is given correctly by :-

The resistance R=(V)/(I) where V=(200+-5)V and I=(20+-0.2)A ,the percentage error in the measurement of "R" is :

The resistance R= (V)/(I) , where V= (100+-5.0) V and I=(10+-0.2)A . Find the percentage error in R .

The resistance R= (V)/(I) , where V= (100+-5.0) V and I=(10+-0.2)A . Find the percentage error in R .