A voltmeter reads upto 3V. Its resistance is 200 Ohm. It is to be used to measure a potential difference which may be as large as 60V. What measure you would take to protect the voltmeter ?

A voltemeter reads up to 3 V. It resistance is 200 ohm. It is to be used to measure a potential difference, which may be as large as 60 V. What measures you would take to protect the voltmeter?

How can a voltmeter of resistance 200 ohm and measuring 10 V be used to measure a current of 5 A?

Two resistances of 400 ohm and 800 ohm are connected in series with 6 volt battery of negligible internal resistance. A voltmeter of resistance 10,000ohm is used to measure the potential difference across 400 ohm. The error in the measurement of potential difference in volt approximately .

A voltmeter of resistance R is to be used to meaure a voltage 100 times as large as it can measure without an additional resistance in seires. How alrge a resistance is to be used in series with the meter?

A battery of e.m.f 12 V supplies a current through a oil of resistance 48 ohm. The internal resistance of the battery is 1.2 ohms. A voltmeter of resistance 72 oohm is sued to measure the potential difference across the coil. What value would it show?

A voltemeter of resitance 400 Omega connected for measurement to a section of a ciruit having a resistance of 20 ohm shows a reading of 100 V. What is the error in the reading of the voltmeter, if the current in the main circit is assumed to remain constant before and after connecting the voltmeter?

A resistance R is connected across a cell of emf epsilon and internal resistance r. A potentiometer now measures the potential difference between the terminals of the cell as V. Write the expression for 'r' in terms of epsilon , V and R.