Free Circuit Analysis MCQs with Answers

• A. A branch formed by the parallel connection of any resistor R and open circuit has the characteristic of an open circuit.
• B. A branch formed by the parallel connection of any resistor R and a short circuit has the characteristic of a short circuit.
• C. A branch formed by the series connection of any resistor R and an open circuit has the characteristic of an open circuit.
• D. A branch formed by the series connection of any resistor R and a short circuit has the characteristic of resistor R.

Explanation: A resistor in parallel with an open circuit remains equivalent to the resistor, not an open circuit.

• A. Constant current source
• B. Constant voltage source
• C. Capacitance
• D. None of the above

Explanation: A capacitor has the same voltage-current relationship regardless of the direction of excitation, so it is bilateral.

• A. non-linear constraints
• B. linear constraints
• C. no constraints
• D. none of the above

Explanation: KVL states that the algebraic sum of voltages around a closed loop is zero, producing linear equations in the branch voltages.

• A. linear, non-linear and time variant responses
• B. linear and non-linear resistors only
• C. linear responses only
• D. none of the above

Explanation: Superposition depends on linearity, because individual source responses can be added only in a linear circuit or system.

• A. series with each other
• B. parallel with each other
• C. series with the voltage source
• D. parallel with the voltage source

Explanation: Elements in the same current path carry the same current, which is the defining condition for series connection.

• A. equal to the load resistance
• B. less than the load resistance
• C. more than the load resistance
• D. none of the above

Explanation: For high efficiency, the source resistance must be much smaller than the load resistance, so only a small fraction of power is lost…

• A. lumped parameters
• B. passive elements
• C. distributed parameters
• D. non-linear resistances

Explanation: The usual Kirchhoff laws assume lumped parameters, where voltage and current can be assigned to discrete elements.

• A. large value of e.m.f.
• B. small value of e.m.f.
• C. zero source resistance
• D. infinite source resistance

Explanation: An ideal voltage source maintains its specified terminal voltage regardless of load current, which requires zero internal or source…

• A. net current flow at the junction is positive
• B. Hebraic sum of the currents meeting at the junction is zero
• C. no current can leave the junction without some current entering it.
• D. total sum of currents meeting at the junction is zero

Explanation: KCL requires the algebraic sum of currents at a junction to be zero, taking entering and leaving currents with opposite signs.

• A. current controlled resistor
• B. voltage controlled resistor
• C. both current controlled and voltage controlled resistor
• D. none of the above

Explanation: For a finite nonzero resistance, V = IR and I = V/R are both valid, so the resistor can be described as both voltage-controlled and…

• A. equivalent current source and impedance in parallel
• B. equivalent current source and impedance in series
• C. equivalent impedance
• D. equivalent current source

Explanation: Norton's equivalent replaces a linear two-terminal network with an equivalent current source in parallel with an equivalent impedance.

• A. a voltage source
• B. a current source
• C. both of above
• D. none of the above

Explanation: Because the source resistance is much smaller than the 100-ohm load, nearly the full source voltage appears across the load and the source…

• A. flux density
• B. reluctance
• C. ampere-turns
• D. resistance

Explanation: Permeance measures how easily magnetic flux is established, just as conductance measures electrical current flow.

• A. Circulating current method
• B. Thevenin's theorem
• C. Superposition of currents
• D. Direct application of Kirehhoffs laws
• E. All of the above

Explanation: Interconnected networks can be solved by loop or circulating-current methods, network theorems such as Thevenin and superposition, or…

• A. one watt
• B. one joule
• C. five joules
• D. one joule second

Explanation: Work or energy equals force multiplied by distance, so one newton metre equals one joule.

• A. resistance : ohm
• B. capacitance : henry
• C. inductance : farad
• D. lumen : steradian

Explanation: Conductance is the reciprocal of resistance and is measured in mho, now commonly called siemens; resistance is measured in ohms.

• A. I2Rt
• B. I2Rf
• C. I2R2t
• D. I2R2t*

Explanation: Joule’s law gives heat energy H = I²Rt, where current is squared and resistance and time are first powers.

• A. 10 W
• B. 20 W
• C. 40 W
• D. 60 W

Explanation: In a parallel circuit, the source supplies the sum of the power absorbed by all branches. Thus, 20 W + 20 W + 20 W = 60 W.

• A. current through supply line flows at slower speed
• B. supply wiring is covered with insulation layer
• C. resistance of heater coil is more than the supply wires
• D. supply wires are made of superior material

Explanation: The same current flows through the heater and its supply wires, but heating power is proportional to I²R.

• A. ohms/°C
• B. mhos/ohm°C
• C. ohms/ohm°C
• D. mhos/°C

Explanation: Temperature coefficient is defined as the change in resistance per ohm of original resistance per degree temperature change, α = ΔR/(RΔT).