37. in a single phase supply, half wave rectifier requires: (a) 1 diode (b) 2 diodes (c) 4 diodes (d) 16 diodes 38. r.m.s. value of no load output d.e. voltage

37. In a single phase supply, half wave rectifier requires: (A) 1 diode (B) 2 diodes (C) 4 diodes (D) 16 diodes 38. R.M.S. value of no load output d.e. voltage of half wave rectifier is: (A) peak2 (B) Vpeak /3 (C) Vpeak/4 (D) Vpeak:/8 39. Maxwell-Boltzmann's law is for the.. (A) Distinguishable particles (B) Indistinguishable particles (C) Particles with half integral spin (D) Particles with integral spin 40. The average kinetic energy associated with each degree of freedom is . (A) KT 3) 2 kT (C)KT/2 (D) KT/4 41. The ratio of r.m.s. velocity to most probable velocity is. (A) 3: V2 (B) 2: 3 (C) 3:2 (D) 2:3 42 Electron emission from a metal source by heating the metal is knownas (A) Photoclectric emission (B) Secondary emission (C) Thermionic emission (D) Field emission