Quantrex Quantrex AcademyJEE · NEET · NDA PYQs with solutions Open app
JEE MainPhysicsCurrent Electricity

A circuit segment consists of a resistor R₁ = 2 k connected in series with a parallel combination of a resistor R₂ = 6 k and an unknown resistor R . This combination is further connected in series with another resistor R₃ = 2 k . The total potential difference across the entire segment is 54 V . If the current flowing through R₂ is 3 mA , the value of the unknown resistor R is

Options

  1. A3 k
  2. B2 k
  3. C6 k
  4. D9 k

Correct answer

A. 3 k

Step-by-step solution

The voltage drop across the parallel combination is given by Ohm's law applied to R₂ : V_p = I_ R₂ R₂ = 3 mA 6 k = 18 V The remaining voltage drops across the series resistors R₁ and R₃ . The sum of their resistances is R₁ + R₃ = 2 k + 2 k = 4 k . The voltage across the series resistors is: V_ series = V_ total - V_p = 54 V - 18 V = 36 V The total current flowing through the main circuit is: I_ total = V_ series R₁ + R₃ = 36 V 4 k = 9 mA By Kirchhoff's Current Law, the total current splits between R₂ and R . The cu

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