A proposal to establish a uniform per kilowatt-hour rate for all users of electricity, one of three placed on the November 2 Massachusetts ballot on Wednesday, could lead to a tuition hike for Harvard students if voters approve the measure.

The lower rates which large users of electricity presently receive would be eliminated under the proposal, increasing the University's electric bill by a "substantial" amount, Donald C. Moulton, assistant vice president for government and community affairs, said last night.

The flat rate would have an "inflationary impact" which would affect private institutions such as hospitals and private colleges, Walter P. Muther, vice president and general counsel of Associated Industries of Massachusetts, a group opposed to the referendum, said yesterday.

Commenting on the proposal's chances for approval, Muther said that the public needs to be educated, and when they "understand the situation better, I don't think it will wash."

Jim Katz, a spokesman for Massachusetts Fair Share, the group which sponsored the petition drive to put the question on the ballot, said yesterday that public opinion is probably in favor of the measure right now but that an expected industry-sponsored campaign in opposition to the flat rate might jeopardize its passage.

The graduated income tax once again will appear on the ballot, as it did in 1972, 1968 and 1962. But Katz said he feels the tax has "a better chance" of passage this time because the Massachusetts House will set the tax rate prior to the November election so that people can see exactly what they will have to pay.

A third question was placed on the ballot on Wednesday, a proposal to ban private possession of handguns, could be decided in court rather than at the polls.

In an unprecedented move, the Massachusetts legislature placed an alternative legislative amendment on the ballot calling for mandatory prison sentences for most crimes committed with a gun. Under Massachusetts law, if both proposals receive over 30 percent of the vote only the one receiving the most votes becomes law.

A spokesman for Middlesex County Sheriff John J. Buckley, president of People Vs. Handguns, a group which backs the handgun ban, said yesterday that placing the alternative measure on the ballot represents an attempt to cloud the issue and a "corruption of the petition process." He said People Vs. Handguns plans to go to court in the next few days to challenge its legitimacy.

Constitutional Prophecy

State Secretary Paul H. Guzzi said in a news conference yesterday that he could not ask the Supreme Court for a ruling on the issue, although the alternative amendment raises questions of "constitutional propriety and ultimate fairness."

State Senator Jack H. Backman, who filed the first bill to ban handguns, said yesterday that he feels the alternative is illegal because it goes beyond the scope of the original petition, since it deals with prison terms for the use of handguns, not the banning of handguns.

Backman also said that the law states that any bill relating to the powers of courts is not a proper petition. He said he feels the legislature was trying to "confuse the voter."

The spokesman for Sherrif Buckley said if the handgun ban question appears on the ballot by itself is a "better than 50 per cent chance that it will be approved," but its chances of passage are slim if the alternative also appears.