RC Source-Free DC Response

Resistance ohms
Capacitance farads
Coefficient
A1

The resistance is ohms.
The capacitance is farads.
The time constant (tau) is seconds.

The voltage function is . The capacitor is acting as a temporary voltage source.

Question: The total power dissipation in an RL series circuit is due to which component?


Answer:

The total power dissipation is due to the resistance.

Maximum Power Transfer in DC Circuits

Question: When is the maximum power delivered from a practical source to a load?


Answer:

Maximum power is delivered to the load when its resistance is equal to the source's internal resistance.

Ideal current source resistance

Question: How much internal resistance does an ideal current source have?


Answer:

An ideal current source has infinite resistance.

Ideal voltage source resistance

Question: How much internal resistance does an ideal voltage source have?


Answer:

An ideal voltage source has zero resistance.

Why a voltmeter is a high resistance instrument

Question: Why is it necessary that a voltmeter be a high resistance instrument?

Answer:

Since a voltmeter is connected in parallel to a circuit element, it should have a high resistance to prevent current passing through the circuit element from passing through it instead. This ensures an accurate voltmeter reading.

Why an ammeter has low resistance

Question: Why is it necessary that an ammeter be a low resistance instrument?

Answer:

Since an ammeter is connected in series to a circuit element, it should have a low resistance to avoid adding to the resistance of the circuit element. This prevents deviations in the value of the current being measured and ensures an accurate meter reading.

Use of a Series Resistor

Question: What device is used to extend the range of a DC voltmeter and how is it connected to the basic meter?


Answer:

A resistor connected in series to the voltmeter can be used to extend the voltmeter's range.