Failed to connect to MySQL: Access denied for user 'examnext_online'@'localhost' (using password: YES)
32 cells, each of emf 3V, are connected in series and kept in a box. Externally the combination shows an emf of 84 V. The number of cells reversed in the combination is:
A. |
zero |
B. |
2 |
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C. |
4 |
D. |
8 |