C. Zero D. Unity Top of Form A B C D Bottom of Form 102) The resistance temperature coefficient of copper is A. 3.93×10 – 5 ohm/ohmoC B. 3.93×10 – 4 ohm/ohmoC C. 3.93×10 – 3 ohm/ohmoC D. 3.93×10 – 6 ohm/ohmoC Top of Form A B C D Bottom of Form 103) The absolute permeability of free space is A. 4π B. 0 C. ∝ D. 1 Top of Form A B C D Bottom of Form 104) The value of absolute permeability of free space in mks system is -
C. 10 − 4 D. 10 − 6 Top of Form A B C D Bottom of Form 148) Pure generally have A. high and low B. high and large C. low and [UPSC IES Elec Engg - I 1992]
Bottom of Form Top of Form A B C D 241) Which of the following is the ferroelectric material ? A. Rochelle salt B. Potassium dihydrogen phosphate C. Barium titanate D. All of the above Top of Form Error! Not a valid embedded object. A Not a valid embedded object. B Error! Not a valid embedded object. C Error! Not a valid embedded object. D Error! Not a valid embedded object. Error! Not a valid embedded object. Not a valid embedded object. Error! Not a valid embedded object. Bottom of Form 242) The dielectric strength of ferroelectric materials depends to a large extent on A. area of hysteresis loop for the material B. presence of magnetic materials in the vicinity C. intensity of electric field D. frequency of applied voltage
Top of Form Error! Not a valid embedded object. A Error! Not a valid embedded object. B Not a valid embedded object. C Error! Not a valid embedded object. D Not a valid embedded object. Error! Not a valid embedded object. Error! Not a valid embedded object. Error! Not a valid embedded object. Bottom of Form 243) The temperature beyond which substances lose their ferroelectric properties, is known as A. Curie temperature B. Critical temperature C. Inversion temperature D. Conversion temperature Top of Form Error! Not a valid embedded object. A Not a valid embedded object. B Error! Not a valid embedded object. C Error! Not a valid embedded object. D Error! Not a valid embedded object. Error! Not a valid embedded object. Error! Not a valid embedded object. Error! Not a valid embedded object. Bottom of Form 244) Materials having a high dielectric constant, which is non-linear, are known as A. elastomers B. ferroelectric materials C. super-die-electrics D. hard die-electrics
Top of Form Error! Not a valid embedded object. A Error! Not a valid embedded object. B Error! Not a valid embedded object. C Error! Not a valid embedded object. D Error! Not a valid embedded object. Error! Not a valid embedded object. Error! Not a valid embedded object. Error! Not a valid embedded object. Bottom of Form 245) of the following materials can be used for temperature upto A. Empire B. Mica C. Paper-oiled D. Polythene Top of Form Error! Not a valid embedded object. A Error! Not a valid embedded object. B Error! Not a valid embedded object. C Error! Not a valid embedded object. D Not a valid embedded object. Error! Not a valid embedded object. Error! Not a valid embedded object. Error! Not a valid embedded object. Bottom of Form 246) Which material can be used at temperatures above 100°C ? A. Paraffin wax. B. Rubber C. Teflon D. Polythene Top of Form
Error! Not a valid embedded object. A Error! Not a valid embedded object. B Error! Not a valid embedded object. C Error! Not a valid embedded object. D Error! Not a valid embedded object. Error! Not a valid embedded object. Not a valid embedded object. Not a valid embedded object. Bottom of Form 247) The electric breakdown strength of a material depends on its A. composition B. thickness C. moisture current D. all of the above Top of Form Error! Not a valid embedded object. A Error! Not a valid embedded object. B Error! Not a valid embedded object. C Error! Not a valid embedded object. D Not a valid embedded object. Error! Not a valid embedded object. Error! Not a valid embedded object. Error! Not a valid embedded object. Bottom of Form 248) Dielectric strength of which of the following material is the highest ? A. Polystyrene B. Soft-rubber C. Porcelain D. Glass Top of Form
Error! Not a valid embedded object. A Not a valid embedded object. B Not a valid embedded object. C Error! Not a valid embedded object. D Error! Not a valid embedded object. Error! Not a valid embedded object. Error! Not a valid embedded object. Error! Not a valid embedded object. Bottom of Form Top of Form Not a valid embedded object. A Not a valid embedded object. B Not a valid embedded object. C Error! Not a valid embedded object. D Error! Not a valid embedded object. Error! Not a valid embedded object. Error! Not a valid embedded object. Error! Not a valid embedded object. Bottom of Form Top of Form Error! Not a valid embedded object. A Not a valid embedded object. B Error! Not a valid embedded object. C Error! Not a valid embedded object. D Not a valid embedded object. Not a valid embedded object. Not a valid embedded object. Error! Not a valid embedded object. Bottom of Form
Error! Not a valid embedded object. A Error! Not a valid embedded object. B Error! Not a valid embedded object. C Error! Not a valid embedded object. D Error! Not a valid embedded object. Error! Not a valid embedded object. Error! Not a valid embedded object. Error! Not a valid embedded object. Bottom of Form Top of Form Error! Not a valid embedded object. A Error! Not a valid embedded object. B Error! Not a valid embedded object. C Error! Not a valid embedded object. D Error! Not a valid embedded object. Error! Not a valid embedded object. Error! Not a valid embedded object. Error! Not a valid embedded object. Bottom of Form Top of Form Error! Not a valid embedded object. A Error! Not a valid embedded object. B Error! Not a valid embedded object. C Error! Not a valid embedded object. D Error! Not a valid embedded object. Error! Not a valid embedded object. Error! Not a valid embedded object. 257) The curie point for Rohelle salt is about A. 500°C B. 1000°C
C. 250°C D. 240°C Top of Form Error! Not a valid embedded object. A Error! Not a valid embedded object. B Error! Not a valid embedded object. C Error! Not a valid embedded object. D Error! Not a valid embedded object. Error! Not a valid embedded object. Error! Not a valid embedded object. Error! Not a valid embedded object. Bottom of Form 258) Piezoelectric materials serve as a source of A. microwaves B. musical waves C. ultrasonic waves D. resonant waves Top of Form Error! Not a valid embedded object. A Error! Not a valid embedded object. B Error! Not a valid embedded object. C Error! Not a valid embedded object. D Error! Not a valid embedded object. Error! Not a valid embedded object. Not a valid embedded object. Error! Not a valid embedded object. Bottom of Form 259) Materials which lack permanent magnetic dipoles are called A. diamagnetic B. ferromagnectic
C. semi-magnetic D. none of the above Top of Form Error! Not a valid embedded object. A Error! Not a valid embedded object. B Error! Not a valid embedded object. C Error! Not a valid embedded object. D Error! Not a valid embedded object. Not a valid embedded object. Error! Not a valid embedded object. Error! Not a valid embedded object. Bottom of Form 260) Germanium has A. ionic bond B. covalent bond C. molecular bond D. metallic bond Top of Form Error! Not a valid embedded object. A Not a valid embedded object. B Error! Not a valid embedded object. C Not a valid embedded object. D Error! Not a valid embedded object. Error! Not a valid embedded object. Error! Not a valid embedded object. Error! Not a valid embedded object. Bottom of Form 261) In ferromagnetic materials A. the atomic magnetic moments are antiparallel and unequal B. the atomic magnetic moments are parallel
C. boro silicate glass D. soda lime glass Top of Form Not a valid embedded object. A Error! Not a valid embedded object. B Not a valid embedded object. C Error! Not a valid embedded object. D Error! Not a valid embedded object. Not a valid embedded object. Error! Not a valid embedded object. Error! Not a valid embedded object. Bottom of Form 264) An alloy containing 71% copper, 28% Zinc and 1% tin is known as A. Admirality brass B. Cartridge brass C. Alpha brass D. Muntz metal Top of Form Error! Not a valid embedded object. A Error! Not a valid embedded object. B Error! Not a valid embedded object. C Error! Not a valid embedded object. D Error! Not a valid embedded object. Error! Not a valid embedded object. Error! Not a valid embedded object. Error! Not a valid embedded object. Bottom of Form
Top of Form Not a valid embedded object. A Error! Not a valid embedded object. B Error! Not a valid embedded object. C Error! Not a valid embedded object. D Not a valid embedded object. Error! Not a valid embedded object. Error! Not a valid embedded object. Error! Not a valid embedded object. Bottom of Form Top of Form Not a valid embedded object. A Error! Not a valid embedded object. B Error! Not a valid embedded object. C Error! Not a valid embedded object. D Error! Not a valid embedded object. Error! Not a valid embedded object. Error! Not a valid embedded object. Error! Not a valid embedded object. Bottom of Form Top of Form Error! Not a valid embedded object. A Error! Not a valid embedded object. B Error! Not a valid embedded object. C Not a valid embedded object. D Not a valid embedded object. Error! Not a valid embedded object. Not a valid embedded object. Error! Not a valid embedded object. Bottom of Form Top of Form
Error! Not a valid embedded object. A Error! Not a valid embedded object. B Error! Not a valid embedded object. C Error! Not a valid embedded object. D Not a valid embedded object. Error! Not a valid embedded object. Error! Not a valid embedded object. Error! Not a valid embedded object. Bottom of Form Top of Form Error! Not a valid embedded object. A Error! Not a valid embedded object. B Error! Not a valid embedded object. C Error! Not a valid embedded object. D Error! Not a valid embedded object. Error! Not a valid embedded object. Not a valid embedded object. Error! Not a valid embedded object. Bottom of Form Top of Form Error! Not a valid embedded object. A Error! Not a valid embedded object. B Error! Not a valid embedded object. C Error! Not a valid embedded object. D Error! Not a valid embedded object. Not a valid embedded object. Error! Not a valid embedded object. Error! Not a valid embedded object. Bottom of Form Top of Form
Error! Not a valid embedded object. A Error! Not a valid embedded object. B Error! Not a valid embedded object. C Error! Not a valid embedded object. D Not a valid embedded object. Error! Not a valid embedded object. Error! Not a valid embedded object. Error! Not a valid embedded object. Bottom of Form Top of Form Error! Not a valid object. A Error! Not a valid object. B lid embedded object. C Error! Not a valid object. D Error! Not a valid object. Error! Not a valid object. 273) When ac supply is given to transformer flux will depends on A. current B. voltage C. frequency D. both voltage and frequency Top of Form