Is the word perguntei the same in Brazilian and European Portuguese?

No

While the meaning, spelling, and grammatical conjugation of "perguntei" (the first-person singular of the past tense verb perguntar) are identical in both Brazilian and Continental Portuguese, there are differences in pronunciation and typical usage (syntax).

In terms of pronunciation, Brazilian Portuguese tends to have more open, resonant vowels, whereas Continental Portuguese features significant vowel reduction, meaning unstressed vowels (like the 'e' in per-) are often "swallowed" or pronounced very softly.

Regarding usage, the primary difference is how the word interacts with the rest of the sentence. In Brazil, it is very common and natural to use the preposition "para" when indicating the person being asked (e.g., perguntei para ele). In Portugal, the preposition "a" is the standard usage (e.g., perguntei-lhe or perguntei ao ele), and the use of clitic pronouns (placing the pronoun after the verb with a hyphen) is much more frequent and natural.

Brazilian Portuguese Examples

1. Eu perguntei para ela se ela ia à festa. (I asked her if she was going to the party.)
2. Perguntei para o meu chefe sobre o aumento. (I asked my boss about the raise.)
3. Eu perguntei o caminho para o shopping. (I asked for the way to the mall.)
4. Perguntei para o rapaz o número do telefone. (I asked the young man for the phone number.)
5. Eu perguntei para todo mundo o que aconteceu. (I asked everyone what happened.)

Continental Portuguese Examples

1. Perguntei-lhe se ia à festa. (I asked him/her if he/she was going to the party.)
2. Perguntei ao meu chefe sobre o aumento. (I asked my boss about the raise.)
3. Perguntei o caminho para o centro. (I asked for the way to the center.)
4. Perguntei ao rapaz o número de telefone. (I asked the young man for the phone number.)
5. Perguntei a todos o que tinha acontecido. (I asked everyone what had happened.)