Correct Answer: Swing curve

Explanation:

The plot between power angle (δ) and time (t) is known as the Swing Curve.

It is used in power system stability studies to analyze how the rotor angle changes with time after a disturbance.

• Swing Curve: δ vs t → Correct

• Power Curve: Usually P vs δ

• Critical Clearing Angle: A specific value, not a plot

• None of the above: Incorrect

For economic operation, the incremental cost rates should be equal:  Solving this equation with the total load constraint  gives the optimal values.

Correct Answer: Induction heating

Explanation:

Skin effect is the tendency of alternating current (AC) to concentrate near the surface of a conductor at high frequencies.

In induction heating, high-frequency AC is used to induce eddy currents in the workpiece. These currents flow mainly on the surface due to skin effect, making the heating process efficient.

Correct Answer: Statement I is true but Statement II is false.

Explanation:

Statement I: "Two ideal current sources with currents I₁ and I₂ cannot be connected in parallel."

True

Two ideal current sources in parallel must force exactly the same current.

If I₁ ≠ I₂, they contradict each other, resulting in an undefined or infinite voltage.

Hence, parallel connection is not allowed unless currents are equal.

Statement II: "Superposition theorem cannot be applied to ideal current sources if these sources are connected in cascade."

False

• "Cascade" is not a meaningful connection term for current sources—current sources are connected in series or parallel, not cascade.

• Superposition theorem can be applied to circuits containing ideal current sources as long as the circuit is linear.

• Ideal current sources do not violate superposition.

PERT stands for Program Evaluation and Review Technique, which is a tool used in project management to analyze and represent the tasks involved in completing a given project.

Diesel plants are often used as peaking power plants due to their ability to start quickly and meet short-term electricity demands.

The manager is emphasizing the development of analytical and critical thinking skills to ensure employees can perform their tasks effectively and make informed decisions.

Correct Answer: Arc stability

Explanation:

DC welding provides:

• Better arc stability → The arc is smoother and easier to maintain.

• AC welding is generally cheaper, has lower power losses, and is preferred for cost and efficiency in many cases.

So the major advantage of DC over AC is:

A perfect set in a topological space is closed and every point is a limit point. The interval [2, 5] fits this definition.

Correct Answer: Armature winding or field winding

Explanation:

A universal motor is a series-wound motor.

The direction of rotation changes when the relative direction of the field current and armature current is reversed.

To reverse rotation, you can:

• Reverse current in armature winding, OR

• Reverse current in field winding

But not both, because doing so keeps relative direction same → rotation unchanged.