Question

1. what type of voltage must be connected to a darsonval meter movement?
2. a dc voltmeter has a resistance of 20,000 \\(\omega\\) per volt. what is the resistance of the meter if the range selection switch is set on the 250-v range?

Explanation:

Identify the operating voltage for a d'Arsonval movement

A d'Arsonval meter movement operates on the electromagnetic interaction between a permanent magnet and a current-carrying coil. Because the magnetic field of the permanent magnet is fixed in direction, the current through the coil must flow in a single direction to produce a consistent, unidirectional torque. Therefore, a d'Arsonval meter movement must be connected to a direct current (DC) voltage.

Define the given parameters for the voltmeter calculation

For the second question, we are given:

• Voltmeter sensitivity (resistance per volt): \(20,000\text{ }\Omega/\text{V}\)
• Selected voltage range: \(250\text{ V}\)

Calculate the total internal resistance of the meter

The total resistance of a voltmeter on a given range is the product of its sensitivity and the full-scale voltage range:

$$R_{\text{total}} = \text{Sensitivity} \times \text{Range}$$

Compute the final numerical value

Substitute the given values into the formula:

$$R_{\text{total}} = 20,000\text{ }\Omega/\text{V} \times 250\text{ V}$$

$$R_{\text{total}} = 5,000,000\text{ }\Omega = 5\text{ M}\Omega$$

Answer:

Question 2

Direct current (DC) voltage.

Question 3

\(5,000,000\text{ }\Omega\) (or \(5\text{ M}\Omega\)).