Current Electricity Charging Discharging Of Capacitors Question 708
Question: A 12 cm wire is given a shape of a right angled triangle ABC having sides 3 cm, 4 cm and 5 cm as shown in the figure. The resistance between two ends (AB, BC, CA) of the respective sides are measured one by one a multi-meter. The resistances will be in the ratio of
Options:
A) 3 : 4 : 5
B) 9 : 16 : 25
C) 27 : 32 : 35
D) 21 : 24 : 25
Show Answer
Answer:
Correct Answer: C
Solution:
[c] Resistance is directly proportional to length $ \frac{1}{R _{AB}}=\frac{1}{3}+\frac{1}{4+5}=\frac{( 4+5 )+3}{( 3 )( 4+5 )} $
$ R _{AB}=\frac{3\times ( 4+5 )}{3+( 4+5 )}=\frac{27}{12} $ Similarly, $ R _{BC}=\frac{4\times ( 3+5 )}{4+( 3+5 )}=\frac{32}{12} $
$ R _{AC}=\frac{5\times ( 3+4 )}{5+( 3+4 )}=\frac{35}{12} $
$ \
Therefore R _{AB}:R _{BC}:R _{AC}=27:32:35 $
BETA
