This question has statement I and statement II. Of the four choices given after the statements, choose the one that best describes the two statements.
Statement-I: Higher the range, greater is the resistance of ammeter.
Statement- II: To increase the range of ammeter, additional shunt needs to be used across it.
Statement-I: Higher the range, greater is the resistance of ammeter.
Statement- II: To increase the range of ammeter, additional shunt needs to be used across it.
- (A)Statement - I is true, Statement - II is true, Statement - II is not the correct explanation of Statement-I.
- (B)Statement - I is true, statement - II is false.
- (C)Statement - I is false, Statement - II is true✓ Correct
- (D)Statement - I is true, Statement - II is true, Statement - II is the correct explanation of statement- I .
Answer: (C)
Solution
An ammeter is a galvanometer with a small shunt across it, related to the full-scale current by . To read larger currents we must divert more of the current through the shunt, which means fitting a smaller shunt resistance and so lowering the meter's overall resistance, not raising it. The claim that a higher range needs greater ammeter resistance is therefore false, while the statement that increasing the range calls for an additional shunt across the meter is true.
JEE Main · 2013 · 07 Apr 2013 · Offline · Single correct option