To shunt exactly 2% of the total current through a galvanometer of internal resistance G, the required shunt resistance is ________________?
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Answer: B. G/49
Explanation
Diverting two percent through the galvanometer leaves ninety-eight percent flowing through the parallel shunt. The ratio of currents equals the inverse ratio of their respective parallel resistances. Dividing internal resistance G by forty-nine gives the exact shunt resistance required for this split. Parallel branches divide total current inversely proportional to their respective electrical resistances. If the galvanometer carries one part, the shunt must carry forty-nine parts to total fifty parts. Ohms law confirms that equal voltage across parallel paths dictates current division ratios.
Instrument design engineers use this exact current splitting math to build multi-range ammeters. Precision calibration requires exact shunt resistor selection to maintain accurate meter scale readings. Electrical testing equipment relies on stable parallel shunt networks for reliable current measurement. G over fifty would divert an incorrect percentage of current away from the galvanometer movement. Forty-nine G represents a high series resistance value rather than a proper parallel shunt. Fifty G is far too large and would force almost all current through the sensitive galvanometer.
- Subject
- Engineering
- Category
- Electrical Engineering
- Topic
- —
- Difficulty
- medium
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