By GLORIA MARINA

A Miami federal grand jury Friday questioned Cuban exiles about the sinking of a Cuban freighter last April and the attempt on the life of the Cuban consul in Merida, Mexico last July.

The jury also asked about Cuban Action - purportedly directed by Dr. Orlando Bosch, now charged in Venezuela with the October bombing of a Cuban airliner in which all 73 persons aboard died.

Among the five Cubans appearing before the grand jury was the wife of Gaspar Jimenez, the man accused by Mexican authorities of trying to kill Daniel Ferrer y Ferrer, the Cuban consul in Merida, and of the slaying of his chief of investigations, Artanan Diaz Diaz.

"They asked me whether I knew my husband had belonged to Cuban Action for the past two years," said Maria del Carmen Jimenez. "and I answered them that Gaspar was a very reserved man and never talked about his affairs."

Jurors also wanted to know whether Mrs. Jimenez had known previously about her husband's planned trip to Mexico. She said he had told her only the eight before. "I even packed his best clothes, his new Christian Dior shirts and socks he hadn't even worn yet."

She said her husband, a railway employee who had just undergone an ulcer operation, had charged the trip to American Express.

The jury also asked how she paid for their house on a teacher's aide salary and still make several trips to Mexico. "I told them we Cubans held together and that people I had never met before have come to my house and given me $5 and $10. Also I told them I have family here helping me ... " she said.

She said she was asked repeatedly about Armando Lopez-Estrada, military commander of Brigade 2506.

Lopez-Estrada, the last Cuban to appear before the federal grand jury, was accompanied by his lawyer, Charles Lidsky.

Three other Cuban exiles appeared before the grand jury before the noon lunch recess. They were:

Jorge Capote, 42-year-old owner of Capote Painting. He said had it was the first time he had been subpenaed before a federal grand jury.

Willy Salgado, a young man dressed in a red leisure suit. He also said it was his first appearance before a federal grand jury.

Manolo Perez, 36-year-old owner of an mechanical repair shop was the last one to appear before the jury recessed, still wearing his mechanic uniform.