EASY
12th ICSE
IMPORTANT
Earn 100

State whether the temperature coefficient of resistance α is positive or negative for C.

Important Questions on Electric Resistance and Ohm's Law

EASY
12th ICSE
IMPORTANT
NOOTAN ISC PHYSICS Class 12 Part-1>Chapter 5 - Electric Resistance and Ohm's Law>QUESTIONS>Q 14
Name one material whose resistivity decreases with rise in temperature. Explain briefly on the basis of free electron theory why resistivity decreases.
EASY
12th ICSE
IMPORTANT
NOOTAN ISC PHYSICS Class 12 Part-1>Chapter 5 - Electric Resistance and Ohm's Law>QUESTIONS>Q 15
Show graphically how electrical resistance of a piece of Silicon or Germanium varies when its temperature is varied.  
EASY
12th ICSE
IMPORTANT
NOOTAN ISC PHYSICS Class 12 Part-1>Chapter 5 - Electric Resistance and Ohm's Law>QUESTIONS>Q 16
Electrons are constantly in motion within metals, but there is no current until a PD is established across it, why?
EASY
12th ICSE
IMPORTANT
NOOTAN ISC PHYSICS Class 12 Part-1>Chapter 5 - Electric Resistance and Ohm's Law>QUESTIONS>Q 17
A current flowing in a copper wire is sent in another copper wire of double the radius. How will the drift velocity of free electrons be affected?
EASY
12th ICSE
IMPORTANT
NOOTAN ISC PHYSICS Class 12 Part-1>Chapter 5 - Electric Resistance and Ohm's Law>QUESTIONS>Q 17
How will the drift velocity of free electrons be affected? If sent in an iron wire of same radius, then?
EASY
12th ICSE
IMPORTANT
NOOTAN ISC PHYSICS Class 12 Part-1>Chapter 5 - Electric Resistance and Ohm's Law>QUESTIONS>Q 18
When electrons drift in a metal from lower to higher potential, does it mean that all the free electrons of the metal are moving in the same direction?
EASY
12th ICSE
IMPORTANT
NOOTAN ISC PHYSICS Class 12 Part-1>Chapter 5 - Electric Resistance and Ohm's Law>QUESTIONS>Q 19
Electrons in metals drift due to the force exerted on them by the electric field. Then, why do they acquire an unaccelerated (steady) velocity?
EASY
12th ICSE
IMPORTANT
NOOTAN ISC PHYSICS Class 12 Part-1>Chapter 5 - Electric Resistance and Ohm's Law>QUESTIONS>Q 20
Are the paths of electrons in metals straight lines between successive collisions (with the positive ions in the metal) in the absence of electric field?