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Question
Consider the sacle of voltmeter shown in the diagram and answer the following questions :
(a) What is the least count of the voltmeter?
(b) What is the reading shown by the voltmeter ?
(c) If the voltmeter is connected across a resistor of 20 `Omega` how much current is flowing through the resistor?
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Solution
(a) Least count = `3/20 = 0.15V`
(b) `(1.5 + 0.15 + 0.15)V = 1.8 V`
(c) R = 20 `Omega`
`V = 1.8 V`
`therefore I = ?`
By ohm’s law
`V = IR`
`1.8/20 = I therefore I = 0.09 A`
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