The Department of Energy cannot force its employees to disclose all of the organizations in which they or members of their families are officials, U.S. District Judge Gerhard A. Gesell ruled yesterday.

The new department had made the "sweeping and somewhat undefined demand," as Gesell called it, in a questionnaire its employes were required to fill out in an attempt to identify possible conflict of interests.

The form had two major parts - one in which the employees disclosed relationships with organizations they knew were energy-related, and the second for all other organizations. The latter part was desired, the government argued, so it could determine if the organizations should have been listed by employees under the first part.

Gesell said: "In this immediately post-Watergate period, the view exists that conflicts of interests can be expunged by forcing intimate disclosures from those dealing with or acting for the government . . .

"We must beware lest excessive zeal in this direction destroy more precious fundamental values. People, even people working for the government, have within reason the right to be left alone."

He said the Energy Department questionnaire amounted to "too much." It exceeds proper bounds and is unreasonable and repressive. Government employees do not waive call their constitutional rights when they enter public service."

Gesell found that the portion of the questionnaire at issue in the suit filed by the American Federation of Government Employees violated the First Amendment. He said employees who have already filled out the form can have the information returned to them and taken out of the department's files.

The form, Gesell said, required employees and their children and spouses to disclose whether they were officials or advisers of churches, fraternities, schools, unions, environmental groups, abortion groups, or virtually any other group.