Month: February 2019

Q. 1Arrange following alloys in decreasing order of their resistivity.     A. Constantan- German silver- monel metal     B. German silver- constantan- monel metal     C. German silver- monel metal- constantan     D. constantan- monel metal- German silver Ans.: A Read More …

Q.1 The thermionic emission is due to which of the following?     A. high temperature     B. electromagnetic field     C. electrostatic field     D. all of the above Ans.: A Q. 2 The electric breakdown strength is affected by Read More …

Q. 1 Dielectric constant for vacuum is___.     A. 100     B. 1     C. zero     D. infinite Ans.: B Q. 2 Which of the following insulating material used in spark plugs?     A. Mica     B. Polysterene     Read More …

Q. 1Which type of copper has good conductivity?     A. Hard drawn copper     B. pure annealed copper     C. copper containing traces of silicon     D. Induction hardened copper Ans.: B Q. 2 ___ is known as aluminium ore. Read More …

Q. 1 Hard ferrites used in     A. Generators, Relays, Motors     B. Electronics applications     C. Holding devices such as seals, latches     D. All of the above Ans.: D Q. 2 Supper-paramagnetic materials, made from powdered iron or Read More …

Q. 1 The properties of soft ferromagnetic materials may be greatly enhanced through _________so as to achieve a high degree of crystal purity.     A. Careful manufacturing     B. by heating     C. slow annealing     D. all of the Read More …

Q. 1 The ___ which repelled by a magnet.     A. ferrites     B. diamagnetic     C. ferromagnetic     D. paramagnetic Ans.: B Q. 2 _______ are an examples of a diamagnetic material.     A. zinc, mercury     B. lead, Read More …