JEE Main201912 Apr 2019Morning ShiftPhysicsCurrent ElectricityActual
To verify Ohm’s law, a student connects the voltmeter across the battery as shown in the figure. The measured voltage is plotted as a function of the current, and the following graph is obtained: If V o is almost zero, identify the correct statement:
Options
- AThe emf of the battery is 1.5 V and its internal resistance is 1.5 Ω
- BThe value of the resistance R is 1.5 Ω
- CThe potential difference across the battery is 1.5 V when it sends a current of 1000 m A
- DThe emf of the battery is 1.5 V and the value of R is 1.5 Ω
Correct answer
A. The emf of the battery is 1.5 V and its internal resistance is 1.5 Ω
Step-by-step solution
V = E - I r when V = V 0 = 0 ⇒ 0 = E - I r ∴   E = I r when I = 0 ,   V = E = 1 . 5   V ∴   r = 1 . 5   Ω .