Quantrex Quantrex AcademyJEE · NEET · NDA PYQs with solutions Open app
JEE Main2012PhysicsCurrent ElectricityActual

In an experiment of potentiometer for measuring the internal resistance of primary cell a balancing length is obtained on the potentiometer wire when the cell is open circuit. Now the cell is short circuited by a resistance R . If R is to be equal to the internal resistance of the cell the balancing length on the potentiometer wire will be

Options

  1. A2
  2. B/ 2
  3. C/ 4

Correct answer

C. / 4

Step-by-step solution

Balancing length l will give emf of cell E=K l Here K is potential gradient. If the cell is short circuited by resistance 'R' Let balancing length obtained be l^ then aligned & V=k l^ & r= ( E-V V ) R & V=E-V & 2 V=E or, & 2 K l^ =K l & l^ = l 2 aligned

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