A DC voltmeter is capable of measuring a maximum of300 volts. If it is used to measure the voltage across a device operating at 220-volt AC supply, the reading of the voltmeter will be

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Q: 54 (CDS-I/2002)
A DC voltmeter is capable of measuring a maximum of300 volts. If it is used to measure the voltage across a device operating at 220-volt AC supply, the reading of the voltmeter will be

question_subject: 

Science

question_exam: 

CDS-I

stats: 

0,12,17,4,10,3,12

keywords: 

{'dc voltmeter': [0, 0, 1, 0], 'voltmeter': [0, 0, 2, 0], 'maximum of300 volts': [0, 0, 1, 0], 'volts': [0, 0, 2, 0], 'volt ac supply': [0, 0, 1, 0], 'voltage': [0, 0, 0, 1]}

The correct answer is option 4: 0 volts.

Since the voltmeter is a DC (direct current) voltmeter, it is designed to measure the voltage of a direct current source. In this case, the device is operating on a 220-volt AC (alternating current) supply, which means it is not a direct current.

AC voltage alternates in polarity, meaning that the voltage constantly changes in direction and magnitude over time. On the other hand, a DC voltage is constant in both direction and magnitude.

As the voltmeter is specifically designed for DC voltage measurements, it will not be able to accurately measure the AC voltage across the device. Therefore, the reading on the voltmeter will be 0 volts, indicating that it cannot measure the AC voltage. It is essential to use an AC voltmeter for accurate measurements of AC voltage.