Effektfaktoren er høy.

Because -en is the definite singular ending for many en-nouns in Bokmål.

• Indefinite: en effektfaktor
• Definite: effektfaktoren

So effektfaktoren means the power factor.
Norwegian usually attaches the definite article to the end of the noun instead of putting a separate word before it.

In Norwegian, the definite article is often built into the noun itself.

Compare:

• English: the power factor
• Norwegian: effektfaktoren

That final -en already contains the idea of the.

You do sometimes also see a separate determiner with adjectives:

• den høye effektfaktoren = the high power factor

But in your sentence, there is no adjective directly before the noun, so the noun just takes the definite ending by itself: effektfaktoren.

The dictionary form is effektfaktor.

Usually you would learn it with its article:

• en effektfaktor = a power factor

From that you get:

• effektfaktoren = the power factor

So if you want to look it up, search for effektfaktor, not effektfaktoren.

Yes. Norwegian very often forms compound nouns as one word, especially in technical language.

So:

• effekt
  • faktor → effektfaktor

This is very normal in Norwegian. English often uses separate words where Norwegian prefers compounds.

Because høy is the correct predicative form for a singular common-gender noun here.

The subject is effektfaktoren, and effektfaktor is an en-noun. After er, adjectives agree like this:

• common gender singular: høy
• neuter singular: høyt
• plural: høye

So:

• Effektfaktoren er høy.
• Nivået er høyt.
• Verdiene er høye.

This is a very common thing learners ask about.

Because the adjective is being used predicatively, not directly in front of the noun.

After verbs like er, blir, and virker, Norwegian uses the normal predicative agreement:

• Effektfaktoren er høy.

But when the adjective comes before a definite noun, it usually takes -e:

• den høye effektfaktoren

So:

• effektfaktoren er høy = adjective after er
• den høye effektfaktoren = adjective before the noun

That is why you see høy here, not høye.

It uses the standard Norwegian main-clause pattern:

• Subject + verb + complement

So here:

• Effektfaktoren = subject
• er = verb
• høy = complement

This is the normal order for a simple statement.

You usually invert the subject and verb:

• Er effektfaktoren høy?

So the statement:

• Effektfaktoren er høy.

becomes the question:

• Er effektfaktoren høy?

This is very similar to English Is the power factor high?

Høy contains the Norwegian vowel combination øy, which can be tricky for English speakers.

A rough guide:

• høy sounds somewhat like the vowel in French oeil or German euch
• it does not sound like English high

The h is pronounced, and the word is one syllable.

If you are approximating, aim for something like:

• hoy with a rounded starting vowel

It is best to listen to native audio, because øy does not have a perfect English equivalent.

Yes. Høy can mean both high and tall, depending on context.

For example:

• et høyt fjell = a tall/high mountain
• høy temperatur = high temperature

In Effektfaktoren er høy, the meaning is clearly high, not tall, because the context is technical.

Yes, if the noun is already understood from context.

• Effektfaktoren er høy.
• Den er høy.

Here den means it, referring back to effektfaktoren.

That is natural if you have already mentioned the noun and do not want to repeat it.

This sentence is standard Bokmål.

In Nynorsk, the adjective would often be høg instead of høy:

• Bokmål: Effektfaktoren er høy.
• Nynorsk: Effektfaktoren er høg.

A learner will most often meet høy first, because Bokmål is more widely used.