Concepts Of Physics MCQ Edition [Volume 2]
- Exam
- Concepts Of Physics MCQ Edition [Volume 2]
- Subject
- Physics
- Chapter
- Electric Current in Conductors
Concepts Of Physics MCQ Edition [Volume 2] · Physics · Electric Current in Conductors
Two nonideal batteries are wired in parallel. Evaluate the...
Two nonideal batteries are wired in parallel. Evaluate the following statements:
(A) The equivalent emf is smaller than either of the individual emfs.
(B) The equivalent internal resistance is smaller than either of the individual internal resistances.
(A) The equivalent emf is smaller than either of the individual emfs.
(B) The equivalent internal resistance is smaller than either of the individual internal resistances.
Options
- AA is correct but B is incorrect
- BB is correct but A is incorrect
- CBoth A and B are correct
- DBoth A and B are incorrect
Correct answer
B. B is correct but A is incorrect
Step-by-step solution
For two batteries connected in parallel with emfs and and internal resistances and , the equivalent emf is given by .
This expression shows that is a weighted average of and . Thus, always lies between and and cannot be smaller than both individual emfs. Hence, statement A is incorrect.
The equivalent internal resistance is given by the parallel combination of the individual internal resistances, .
In a parallel combination of resistors, the equivalent resistance is always strictly less than the smallest individual resistance. Hence, statement B is correct.
This expression shows that is a weighted average of and . Thus, always lies between and and cannot be smaller than both individual emfs. Hence, statement A is incorrect.
The equivalent internal resistance is given by the parallel combination of the individual internal resistances, .
In a parallel combination of resistors, the equivalent resistance is always strictly less than the smallest individual resistance. Hence, statement B is correct.