Derive an expression for complex fourier series coefficients, sk, for a square pulse train with a frequency of 30.72mhz and an amplitude of a. what are the frequencies and amplitude values of the dc term and the first three harmonics ?

The y form of iron is known as: a) ferrite b) cementite c) perlite d) austenite

Apiston-cylinder with a volume of 0.25 m3 holds 1 kg of air (r 0.287 k/kgk) at a temperature of 100 c. heat transfer to the cylinder causes an isothermal expansion of the piston until the volume triples. how much heat is added to the piston-cylinder?

The higher the astm grain-size number, the coarser the grain is. a)-true b)-false