A circuit you’re building needs an ammeter that goes from 0 mA to a full-scale reading of 50.0 mA. Unfortunately, the only ammeter in the storeroom goes from 0 μ A to a full-scale reading of only 500 μ A . Fortunately, you can make this ammeter work by putting it in a measuring circuit, as shown in Figure P23.66. This lets a certain fraction of the current pass through the meter; knowing this value, you can deduce the total current. Assume that the ammeter is ideal. a. What value of R must you use so that the meter will go to full scale when the current I is 50.0 mA? Hint: When I = 50.0 mA, the ammeter should be reading its maximum value. b. What is the equivalent resistance of your measuring circuit? Figure P23.66
A circuit you’re building needs an ammeter that goes from 0 mA to a full-scale reading of 50.0 mA. Unfortunately, the only ammeter in the storeroom goes from 0 μ A to a full-scale reading of only 500 μ A . Fortunately, you can make this ammeter work by putting it in a measuring circuit, as shown in Figure P23.66. This lets a certain fraction of the current pass through the meter; knowing this value, you can deduce the total current. Assume that the ammeter is ideal. a. What value of R must you use so that the meter will go to full scale when the current I is 50.0 mA? Hint: When I = 50.0 mA, the ammeter should be reading its maximum value. b. What is the equivalent resistance of your measuring circuit? Figure P23.66
A circuit you’re building needs an ammeter that goes from 0 mA to a full-scale reading of 50.0 mA. Unfortunately, the only ammeter in the storeroom goes from 0 μA to a full-scale reading of only 500 μA. Fortunately, you can make this ammeter work by putting it in a measuring circuit, as shown in Figure P23.66. This lets a certain fraction of the current pass through the meter; knowing this value, you can deduce the total current. Assume that the ammeter is ideal.
a. What value of R must you use so that the meter will go to full scale when the current I is 50.0 mA?
Hint: When I = 50.0 mA, the ammeter should be reading its maximum value.
b. What is the equivalent resistance of your measuring circuit?
Consider the circuit shown in Figure P18.9. (R = 28.0 2.)
10.0 2
25.0 V
W
10.0 2
E.00 a
5.00 2
ER
Figure P18.9
(a) Find the current in the 28.0 2 resistor.
A
(b) Find the potential difference between points a and b.
27
You have an aluminum bar of dimensions 2.0 cm × 5.0 cm × 10 cm. You want to insert it into an electric circuit so that it will have the smallest possible resistance.
Which pair of opposite faces should you connect to the circuit?
The two figure panels show two ways to connect a real (non-ideal) voltmeter and a real ammeter in a circuit to calculate the resistance R. The internal resistance of the voltmeter is Rv and the internal resistance of the ammeter is Ra. The current flows from left to right in both panels, and the potential difference Vac between points a and c in both panels is the same.
In panel (a) the voltmeter reads Vac = 12.1 V and the ammeter reads I1 = 0.098 A.
In panel (b) the voltmeter reads Vab = 12.0 V and the ammeter reads I2 = 0.100 A.
I need help with Part E.
Chapter 23 Solutions
College Physics: A Strategic Approach (3rd Edition)
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DC Series circuits explained - The basics working principle; Author: The Engineering Mindset;https://www.youtube.com/watch?v=VV6tZ3Aqfuc;License: Standard YouTube License, CC-BY