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MODEL PAPER 5 — Physics STD 12 Science — Question

Bihar BoardEnglish MediumSTD 12 SciencePhysicsMODEL PAPER 52 Marks
Question
a. It is not advisable to use a galvanometer as such to measure current directly. Why?
b. Why should the value of resistance connected in parallel to a galvanometer be low?
c. Is the reading shown by an ammeter in a circuit less than or more than the actual value of current flowing in the circuit? Why?
✓

Answer

a. It will not measure accurate value of current because its high resistance will affect the current in the circuit.
b. To reduce the galvanometer resistance a small resistance is connected in parallel.
c. It is less than the actual value of current because it has some resistance which consume some energy and hence the reading shown by an ammeter in a circuit less than the actual value of current flowing in the circuit.

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