Quantrex Quantrex AcademyJEE · NEET · NDA PYQs with solutions Open app
JEE Main201912 Jan 2019Morning ShiftPhysicsCurrent ElectricityActual

The galvanometer deflection, when key K 1 is closed but K 2 is open, equals θ 0 (see figure). On closing K 2 also and adjusting R 2 to 5 Ω , the deflection in galvanometer becomes θ 0 5 . The resistance of the galvanometer is, then, given by [Neglect the internal resistance of battery]:

Options

  1. A12 Ω
  2. B22 Ω
  3. C5 Ω
  4. D25 Ω

Correct answer

B. 22 Ω

Step-by-step solution

θ​ 0 ∝ i G ⇒ θ​ 0 C = i G I-case C θ 0 = V 220 + R ......(i) II-case C θ 0 5 = V 220 + 5 R 5 + R × 5 5 + R ....(ii) From (i) and (ii) R = 22 Ω

Practice Current Electricity on Quantrex Academy →

More from Current Electricity

A metal wire of cross-sectional area 0.5 mm ^2 and length 100 m is connected across a battery of e.m.f. 2 V and internal resistance 1 . The density, atomic mass and electrical cond 2026As shown in the figure, the resistance of a galvanometer G can be found by the half-deflection method. Here the resistance R₂ is adjusted such that when the key K is closed the def 2026The stored charge in the capacitor in steady state of the following circuit is ________ C. 2026A moving coil of galvanometer when shunted with 2 , resistance gives a full scale deflection for a current of 500 mA. When a resistance of 470 , is connected in series it gives a f 2026Two cells of emfs 1 V and 2 V and internal resistance 2 , and 1 , , respectively connected in parallel, gave a current of 1 A through an external resistance. If the polarity of one 2026Refer to the circuit diagram given below. The heat generated across the 6 , resistance in 100 second is 100 J. The value of is _______. (Nearest integer) 2026In an experiment to determine the resistance of a given wire using Ohm's law, the voltmeter and ammeter readings are noted as 10 V and 5 A , respectively. The least counts of voltm 2026Under steady state condition the potential difference across the capacitor in the circuit is _______ V. 2026 Full Current Electricity list All JEE Main PYQs