EEE weekly test

What is Ohm's Law?

• V=I²RV

• V=IR

Answer explanation

Ohm's Law states that the voltage (V) across a conductor is directly proportional to the current (I) flowing through it, with the resistance (R) being the constant of proportionality. Thus, the correct formula is V=IR.

Kirchhoff’s Current Law (KCL) states that:

• The algebraic sum of currents at a junction is zero

• The algebraic sum of voltages in a closed loop is zero

• The total current entering a node equals the total current leaving the node

• Both A and C

Answer explanation

Kirchhoff’s Current Law (KCL) states that the total current entering a node equals the total current leaving the node, which implies that the algebraic sum of currents at a junction is zero. Thus, both A and C are correct.

In Kirchhoff’s Voltage Law (KVL), the sum of all potential differences in a closed loop is:

• 1. Infinity

• Zero

• 1. Equal to current

• Maximum

Answer explanation

According to Kirchhoff’s Voltage Law (KVL), the sum of all potential differences in a closed loop is always zero. This means that the energy supplied in the loop equals the energy consumed, confirming the correct answer is zero.

• In star to delta conversion, the value of each delta resistance is equal to:

• • Sum of star resistances

• • Product of star resistances divided by the opposite star resistance

• • Reciprocal of star resistances

• • None of the above

Answer explanation

In star to delta conversion, each delta resistance (R_delta) is calculated using the formula R_delta = (R1 * R2) / R3, where R1, R2, and R3 are the star resistances. Thus, the correct choice is the product of star resistances divided by the opposite star resistance.

Which configuration is better suited for high voltage applications?

• Delta

• Star

• Both are equally suited

• None of the above

Answer explanation

The Star configuration is better suited for high voltage applications because it allows for higher voltage levels between phases and provides better insulation, reducing the risk of electrical faults compared to the Delta configuration.

Thevenin’s theorem is used to:

• Find the equivalent resistance of a network

• Simplify a network to a single voltage source and resistance

• Analyze AC circuits only

• None of the above

Answer explanation

Thevenin’s theorem simplifies a complex network into a single equivalent voltage source and resistance, making circuit analysis easier. Thus, the correct choice is to simplify a network to a single voltage source and resistance.

Superposition theorem is valid only for:

• Nonlinear circuits

• Bilateral circuits

• Linear circuits

• None of the above

Answer explanation

The superposition theorem applies only to linear circuits, where the principle of superposition holds true. In nonlinear circuits, the response is not directly proportional to the input, making the theorem invalid.

Norton’s equivalent consists of:

• A voltage source in series with resistance

• A current source in parallel with resistance

• Only a current source

• Only a resistance

Answer explanation

Norton’s theorem states that any linear circuit can be replaced by a current source in parallel with a resistance. Thus, the correct answer is a current source in parallel with resistance.

The SI unit of electrical power is:

• Joule

• Volt

• Watt

• Ampere

Answer explanation

The SI unit of electrical power is the Watt. It is defined as one Joule per second and measures the rate of energy transfer. Other options like Joule, Volt, and Ampere represent energy, voltage, and current, respectively.

In an electrical circuit, energy is measured in:

• Volts

• Joules

• Amperes

• Watts

Answer explanation

In an electrical circuit, energy is measured in Joules. Volts measure electric potential, Amperes measure current, and Watts measure power, which is the rate of energy transfer. Thus, Joules is the correct answer.