Explanation

To find the value of 4x + 2y, we can multiply the given equation 2x + y = 5 by 2.

Multiplying both sides by 2 gives:

4x + 2y = 2(5)

4x + 2y = 10

So, the correct answer is: 10

Explanation

A capacitor consists of two conductors separated by a non-conductive region.

It stores electrical energy in an electric field between the conductors.

Explanation

The quantity known as the equivalent resistance indicates the total resistance of the circuit.

It combines the effects of all resistors in the circuit into a single, overall resistance value.

Explanation

Commutators and brushes are recommended for high DC voltage generators because they produce sparks.

This happens due to the intermittent contact, which helps in maintaining unidirectional current flow but requires careful management to avoid excessive sparking and wear.

Explanation

In a gasoline vehicle, a capacitor/spark plug tends to prevent an arc at the contacts.

The capacitor is often part of the ignition system.

It helps suppress electrical noise and ensures smoother operation of the ignition system by minimizing arcing.

Explanation

We need to choose a 4-student committee from a panel of 12 students. This is a combination problem, as the order of selection doesn't matter. We can use the combination formula:

C(n, k) = n! / (k!(n-k)!)

where n is the total number of students (12), k is the number of students to be chosen (4), and ! denotes the factorial function.

C(12, 4) = 12! / (4!(12-4)!)

= 12! / (4!8!)

= (12 × 11 × 10 × 9) / (4 × 3 × 2 × 1)

= 495

So, there are 495 different ways to choose a 4-student committee from a panel of 12 students.

Explanation

Sum of the 5 number = -10 * 5 = -50

Sum of the 3 numbers = 16

Sum of other 2 numbers = -50 - 16 = -66

Average of the 2 numbers = -66/2 = -33.

Explanation

If the frequency of electricity is doubled, the efficiency of the load decreases.

This is because electrical devices and systems are designed to operate optimally at a specific frequency, and doubling it can disrupt their performance.

Explanation

KVA (Kilovolt-Ampere) is used to express the apparent power capacity of an electrical generator or transformer.

It representing the total power without considering the power factor.

It combines both real power (in KW) and reactive power (in KVAR).

Explanation

Porcelain is an insulating material with high resistance to electrical current.

This making it suitable for use in insulators for electrical wiring and components.

In contrast, Aluminum, Copper, and Silver are conductors that allow electrical current to flow easily.