Current Electricity, Charging & Discharging Of Capacitors / वर्तमान बिजली, चार्ज और कैपेसिटर का निर
JEE Main & Advanced
Physics
Current Electricity, Charging & Discharging Of Capacitors / वर्तमान बिजली, चार्ज और कैपेसिटर का निर
Question Bank
Electric Conduction, Ohm's and Resistance
question_answer
The resistance of a wire is R. If the length of the wire is doubled by stretching, then the new resistance will be [Roorkee 1992; AFMC 1995; KCET 1993; AMU (Med.) 1999; CBSE PMT 1999; MP PET 2001; UPSEAT 2001]
A) 2R
B) 4R
C) R
D) \[\frac{R}{4}\]
Correct Answer:
B
Solution :
\[R\propto {{l}^{2}}\] Þ If l doubled then R becomes 4 times.