Recall Test

What is resistance and what factors affect a conductor's resistance?

Answer explanation

Resistance is the opposition to the flow of electric current in a conductor. Factors affecting it include the material's resistivity, length, cross-sectional area, and temperature.

Fill in the blank: The unit of electric current is __________.

Answer explanation

The unit of electric current is called the Ampere, often abbreviated as 'A'. It is a fundamental unit in the International System of Units (SI) used to measure the flow of electric charge.

What is Ohm’s Law and its mathematical form?

Answer explanation

Ohm's Law states that the current (I) through a conductor between two points is directly proportional to the voltage (V) across the two points and inversely proportional to the resistance (R). Its mathematical form is V = I × R.

A 10V battery is connected to a resistor. If the current is 2A, find the resistance.

Answer explanation

Using Ohm's Law (V = IR), where V is voltage, I is current, and R is resistance, we can rearrange the formula to find R: R = V/I. Substituting the values, R = 10V / 2A = 5Ω. Thus, the resistance is 5 ohms.

Define node and Branch,

Answer explanation

A node is a fundamental part of a data structure, representing a single element, while a branch is a connection between nodes, indicating a relationship or path in structures like trees or graphs.

State Kirchhoff’s Current Law (KCL) in your own words.

Answer explanation

Kirchhoff’s Current Law states that the total electric current entering a junction must equal the total current leaving that junction, ensuring conservation of charge in electrical circuits.

If 4A current enters a junction and two branches carry 1.5A and 2A away, what is the current in the third branch?

Answer explanation

According to Kirchhoff's current law, the total current entering a junction equals the total current leaving. Here, 4A enters, and 1.5A + 2A leaves, totaling 3.5A. Thus, the current in the third branch is 4A - 3.5A = 0.5A.

What happens to current in a circuit if voltage is constant but resistance increases?

Answer explanation

According to Ohm's Law (V = I * R), if voltage (V) is constant and resistance (R) increases, the current (I) must decrease. Therefore, as resistance increases, the current in the circuit will decrease.

Define Mesh and loop in an electrical circuit.

Answer explanation

A mesh in an electrical circuit is a loop that does not enclose any other loops, while a loop is any closed path in the circuit. Both concepts are essential for applying mesh and loop analysis in circuit theory.

A circuit loop has a 12V battery and three resistors (2Ω, 1Ω, 3Ω) in series. Use KVL to find the total current in the loop.

Answer explanation

Using KVL, the total resistance is 2Ω + 1Ω + 3Ω = 6Ω. Applying Ohm's law, I = V/R = 12V/6Ω = 2A. The total current in the loop is 2A.