Quantrex Quantrex AcademyJEE · NEET · NDA PYQs with solutions Open app
NEETPhysicsCurrent Electricity

Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R). Assertion (A): To increase the current measuring range of an ammeter, a smaller shunt resistance must be connected in parallel to the galvanometer. Reason (R): The effective resistance of an ammeter is always less than the resistance of the galvanometer used to construct it. In the light of the above statements,

Options

  1. ABoth Assertion (A) and Reason (R) are correct and Reason (R) is the correct explanation of Assertion (A)
  2. BBoth Assertion (A) and Reason (R) are correct but Reason (R) is not the correct explanation of Assertion (A)
  3. CAssertion (A) is correct but Reason (R) is incorrect
  4. DAssertion (A) is incorrect but Reason (R) is correct

Correct answer

B. Both Assertion (A) and Reason (R) are correct but Reason (R) is not the correct explanation of Assertion (A)

Step-by-step solution

Assertion (A) is correct: The shunt resistance S required to convert a galvanometer of resistance G and full-scale current I_g into an ammeter of range I is given by S = I_g G I - I_g . As the required range I increases, the denominator (I - I_g) increases, which means a smaller shunt resistance S is needed. Reason (R) is correct: An ammeter is formed by connecting a shunt resistance in parallel with a galvanometer. In a parallel combination, the equivalent resistance is always less than the smallest individual res

Practice Current Electricity on Quantrex Academy →

More from Current Electricity

A potentiometer wire of 400 cm length has a resistance of 20 . It is connected in series with a resistance of 15 and a accumulator of EMF 6 V (negligible internal resistance). The 2026In the following figure current I equal to 2026The range of voltmeter is 10 V and its resistance is 50 . To convert it to a voltmeter of range 15 V , how much resistance is to be added? 2026When a galvanometer is shunted with a 2 resistance, the deflection is reduced to one-fourth. If the galvanometer is further shunted with a 1 resistance, the further reduction in de 2026A galvanometer can be converted into a voltmeter of certain range by connecting a resistance of 990 in series with it. When the resistance of 480 is connected in series, the range 2026A resistance is to be measured using a meter bridge; the student chooses the standard resistance R to be 100 . The student finds the null point at l₁=16 cm. To get the null point n 2026Which of the following statements is FALSE? A. In a balanced Wheatstone bridge, if the cell and the galvanometer are exchanged, the null point is disturbed. B. A rheostat can be us 2026A potentiometer wire has length 4 m and resistance 8 . The resistance that must be connected in series with the wire and the driving battery of e.m.f. 2 V, so as to get a potential 2026 Full Current Electricity list All NEET PYQs