Quantrex Quantrex AcademyJEE · NEET · NDA PYQs with solutions Open app
NTA Abhyas JEE Main2020PhysicsCurrent ElectricityPractice

In the circuit shown in the figure (A), R 3 is a variable resistance. As the value R 3 is changed, the current I through the cell varies as shown in the figure (B). As R 3 → ∞ , the current I → 6 A . What is the value of the sum of the resistances R 1 and R 2 in ohms?

Correct answer

4

Step-by-step solution

For R 3 = 0 , I = 9 A (from the graph).In this situation, the circuit can be drawn as shown in figure A . [current through R 2 will be zero because we have a short circuit R 3 = 0 across R 2 ] Here I = 36 R 1 + R 2 = 9 A R 1 + R 2 = 4 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 NTA Abhyas JEE Main PYQs