Piezoelectric materials serve as a source of ____________ ?
(A) resonant waves
(B) musical waves
(C) microwaves
(D) ultrasonic waves
Solder is an alloy of______________?
(A) copper and aluminium
(B) tin and lead
(C) nickel, copper and zinc
(D) silver, copper and lead
In thermocouples which of the following pairs is commonly used ?
(A) Copper-constantan
(B) Aluminium-tin
(C) Silver-German silver
(D) Iron-steel
Carbon electrodes are not used in_______________?
(A) GLS lamps
(B) electric arc furnace
(C) dry cells
(D) cinema projectors
___________ is most commonly used for making magnetic recording tape?
(A) Silver nitrate
(B) Ferric oxide
(C) Small particles of iron
(D) Silicon-iron
A carbon resistor contains_____________?
(A) carbon crystals
(B) solid carbon granules
(C) pulverized coal
(D) finely divided carbon black
In graphite, bonding is____________?
(A) covalent
(B) metallic
(C) Vander Waals
(D) Vander Waals and covalent
Non-linear resistors______________?
(A) produce harmonic distortion
(B) follows Ohm’s law at low temperatures only
(C) result in non-uniform heating
(D) none of the above