A conducting wire is drawn to double its length . Final resistivity of material will be : - A ) increased , B ) decreased , C ) no change , D ) None of these ,

1 ) A conducting wire is drawn to double its length .  Final resistivity of material will be : -

A ) increased ,                                                                      B ) decreased ,

C ) no change ,                                                                     D ) None of these ,

Correct Answer : -   C ) no change ,

So resistivity will remain Same .  It is property of wire does not depend on its length , mass or cross - sectional area .

 

2 ) The resistance of an incandescent lamp . . . . . . . . . . . when switched on .

A ) increases ,                                                                       B ) decreases ,

C ) no change ,                                                                     D ) None of these ,

Correct Answer : -   A ) increases ,

 

3 ) . . . . . . . . . . are usually made of metal oxides with temperature coefficient of resistivity .

A ) Thermistors ,                                                                   B ) Amplifiers ,

C ) Diodes ,                                                               D ) None of these ,

Correct Answer : -   A ) Thermistors  ,

 

4 ) Current provided by a battery is maximum , when internal resistance is . . . . . . . . . . external resistance .

A ) greater than ,                                                                  B ) lesser than ,       

C ) equal to ,                                                             D ) None of these ,

Correct Answer : -   C ) equal to ,

 

5 )  . . . . . . . . . is an arrangement of  two different metals to convert heat energy into electrical energy .

A ) Thermistor ,                                                                     B ) Thermocouple ,

C ) Capacitor ,                                                                      D ) None of these ,

Correct Answer : -  B ) Thermocouple ,

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