Electric Circuits Flashcards

Which of the following corresponds to a specific quantity?

Answer: Length

A 'specific quantity' refers to a measurable physical property that has a definite unit. Length is a fundamental physical quantity, measured in units like meters, and is a direct, specific measurement. Money is an economic concept, and polarity is a characteristic (e.g., positive/negative) rather than a scalar quantity with magnitude and unit in the same way as length or pressure. While pressure is also a specific quantity, length is a more fundamental and universally understood example.

The fundamental measure of light intensity is

Answer: Candela

Candela (cd) is the SI base unit of luminous intensity. It quantifies the power emitted by a light source in a particular direction, per unit solid angle, weighted by the luminosity function. This makes it the fundamental measure for how bright a light source appears to the human eye.

Which of the following relationships is correct?

Answer: Tera>Giga>Mega

These are standard SI prefixes used to denote multiples of units. Tera (T) represents 10^12, Giga (G) represents 10^9, and Mega (M) represents 10^6. Therefore, Tera is larger than Giga, and Giga is larger than Mega, establishing the correct descending order of magnitude.

The charge is

Answer: Bipolar

Electric charge exists in two fundamental forms: positive and negative. Objects can either have an excess of positive charge (protons) or negative charge (electrons). This dual nature, having two distinct poles or types, is why charge is described as bipolar.

The symbol used to indicate Unbiased sources

Answer: Circle

In circuit diagrams, independent (unbiased) voltage and current sources are typically represented by a circle. A circle with a plus and minus sign indicates an independent voltage source, while a circle with an arrow indicates an independent current source. This convention distinguishes them from dependent sources, which are usually represented by diamonds.

Positive power is defined as:

Answer: Power is being delivered to circuit

In circuit analysis, a common convention for positive power is that it signifies power being absorbed by or delivered *to* a component or circuit. Conversely, negative power often indicates that power is being supplied *by* the component (e.g., a source). This convention helps in consistently tracking energy flow within a system.

The element of an inductor is .

Answer: Passive

An inductor is a passive circuit element because it can only absorb or store energy, not generate it. Passive elements like resistors, capacitors, and inductors do not require an external power source to operate and cannot amplify signals. Active elements, in contrast, can generate power or amplify signals.

The ability of materials to obstruct the current flow is

Answer: Resistance

Resistance is the electrical property of a material that opposes the flow of electric current. It quantifies how much a material impedes the movement of charge carriers. Materials with high resistance are insulators, while those with low resistance are conductors.

Dependent sources have been ____________ types.

Answer: 4

Dependent sources are classified into four types based on what controls them and what type of source they are. These are: voltage-controlled voltage source (VCVS), current-controlled voltage source (CCVS), voltage-controlled current source (VCCS), and current-controlled current source (CCCS). Each type represents a unique dependency relationship.

When dealing with a dependent voltage/current source, its value is determined by .

Answer: Voltage/current source present somewhere in the circuit

Dependent sources, also known as controlled sources, have their output voltage or current determined by a voltage or current elsewhere within the *same* circuit. Unlike independent sources whose values are constant, a dependent source's value is a function of another circuit variable. This characteristic is crucial for modeling active devices like transistors.

They are depending on some other source, as indicated by the name dependent. The amount of a voltage/current source present someplace in the circuit itself determines the value of a dependent voltage/current source. Which source in an ICVS is controlled and which one is dependent?

Answer: V-dependent, I-controller

An ICVS typically refers to a Current-Controlled Voltage Source (CCVS). In this type of dependent source, the output voltage (V) is dependent on, or controlled by, a current (I) elsewhere in the circuit. Therefore, the voltage is the dependent quantity, and the current is the controller.

What is dependent sources' alternate name?

Answer: Controlled sources

Dependent sources are also widely known as controlled sources because their output (voltage or current) is controlled by another voltage or current elsewhere in the circuit. This terminology highlights their functional dependency on other circuit variables, distinguishing them from independent sources.

The Superposition concept is upheld by .

Answer: Linear networks

The Superposition Theorem is a fundamental principle applicable only to linear circuits. It states that in a linear circuit with multiple independent sources, the total response (voltage or current) at any point is the sum of the responses caused by each independent source acting alone. This theorem relies on the properties of linearity, such as homogeneity and additivity.

Where the voltage division issue appears

Answer: Series connected resistors

Voltage division occurs when resistors are connected in series. In a series circuit, the total voltage across the combination is divided among the individual resistors in proportion to their resistance values. The current, however, remains the same through all series components.

What causes the current divide issue

Answer: Parallel connected resistors

Current division occurs when resistors are connected in parallel. In a parallel circuit, the total current entering the junction divides among the parallel branches. The current through each branch is inversely proportional to its resistance, while the voltage across all parallel components remains the same.

What justifies the current division?

Answer: In parallel current differs

Current division is a direct consequence of Kirchhoff's Current Law (KCL) applied to parallel branches. When components are in parallel, they share the same voltage, but the total current splits among them. The amount of current flowing through each branch depends on its individual resistance, leading to different currents in different parallel paths.