RRB Technician 2013 Ques 27
Question: The effective resistance between points A and B is
Options:
A) $ 60\Omega $
B) $ 40\Omega $
C) $ 20\Omega $
D) $ 10\Omega $
Show Answer
Answer:
Correct Answer: D
Solution:
- It is a balanced Wheatstone’s bridge. Condition of balanced bridge indicates that no current flows through the diagonal resistance. This diagonal branch is the usual galvanometer branch of the bridge. The upper two resistances are in series between AB.
$ \therefore $ Resultant resistance $ 10+10=20,\Omega $ . Similarly, the lower two resistances $ 10+10=20,\Omega $ . The upper and the lower branches are in parallel with each other between A and B. $ R _{AB}=\frac{20\times 20}{20+20}=10,\Omega $
BETA
