Which of the following statement is correct_______________?
(A) A semi-conductor is a material whose conductivity is same as between that of a conductor and an insulator
(B) A semi-conductor is a material which has conductivity having average value of conductivity of metal and insulator
(C) A semi-conductor is one which con¬ducts only half of the applied voltage
(D) A semi-conductor is a material made of alternate layers of conducting material and insulator
The condition for the validity under Ohm’s law is that_______________?
(A) resistance must be uniform
(B) current should be proportional to the size of the resistance
(C) resistance must be wire wound type
(D) temperature at positive end should be more than the temperature at negative end
Which of the following does not change in a transformer ?
(A) Current
(B) Voltage
(C) Frequency
(D) All of the above
One newton meter is same as_____________?
(A) one watt
(B) one joule
(C) five joules
(D) one joule second
Conductance : mho :: ____________?
(A) resistance : ohm
(B) capacitance : henry
(C) inductance : farad
(D) lumen : steradian
Which of the following can have negative temperature coefficient _____________?
(A) Compounds of silver
(B) Liquid metals
(C) Metallic alloys
(D) Electrolytes
When a voltage of one volt is applied, a circuit allows one micro ampere current to flow through it. The conductance of the circuit is___________?
(A) 1 n-mho
(B) 106 mho
(C) 1 milli-mho
(D) none of the above
Nichrome wire is an alloy of_____________?
(A) lead and zinc
(B) chromium and vanadium
(C) nickel and chromium
(D) copper and silver
If/, R and t are the current, resistance and time respectively, then according to Joule’s law heat produced will be proportional to_______________?
(A) I2Rt
(B) I2Rf
(C) I2R2t
(D) I2R2t*