The Virginia Senate passed and sent to the House yesterday a bill that would allow a one-percentage point increase in the sales tax in Northern Virginia to raise money to finance Metro subway operating costs and other mass transportation needs.

The increase would be tacked on to the current 4 percent sales tax and would raise between $34 million and $35 million in the year starting in the year starting July 1. Two-thirds of the revenue would go toward Metrorail expenses and the other third to such transprtation needs as special highway lanes for buses, and car pools, and parking lots.

If the bill is passed by the House, which some Northern Virginians said is unlikely, it also would have to be signed, it also would have to be signed by Gov. John N. Dalton before going into effect. "He said he'd keep an open mind" on the issue, said Sen. Omer Hirst (D-Fairfax), the measure's chief sponsor.

Meanwhile, Dalton announced that he would officially release today $10 million for "Metro subway construction that was appropriated by the General Assembly in the current two (See VIRGINIA, A4, Col.1) (VIRGINIA, From A1) year budget. At the insistence of former governor Mills E. Godwin, the appropriation was tied to the governor's approval of a financial plan for further future Metro construction.

Dalton has consulted several times with Metro and Northern Virginia officials and apparently feels the interim financing agreement that would pay for completion of 60 miles of the proposed 100-mile system is adequate.

The problem of finding money to finance the ever-increasing cost of Metrorail has been a recurring theme of the legislatrue in recent years. Two years ago a measure was passed that would have permitted five Northern Virginia jurisdictions to impose a 4 percent tax on gasoline sales that would have raised $22 million toward Metro costs. However, that tax was tied to approval by all five localities and Fairfax City refused to go along. On Saturday, the House of Delegates approved an extension of that tax, but with the same restriction.

The tax approved by the Senate yesterday does not have that requirement; rather, elected representatives of 90 percent of the estimated 850,000 people in the Northern Virginia transportation district must approve the tax. This means that even if Fairfax City and Falls Church disapprove, the tax can be assessed in those two jurisdictions anyway, as well as in Fairfax and Arlington counties and Alexandria.

"The purpose is to regionalize both the levy and the benefits," Hirst said." . . . Part of the bill requires us to come with a regional transportation plan".

"This will eliminate a substantial burden on the property tax and distribute the burden to Metro costs over a broader segment of the population," said Sen. Wiley F. Mitchell (R. Alexandria), another sponsor of the bill. "And it will eliminate the constant bickering over how future deficits might have an impact on different jurisdicions."

The state is generally reluctant to yield any sales tax authority to localities, where the major sources of revenue are property and license taxes. This reluctance is expected to figure in the House Finance Comittee's consideration of the bill, where it is sure to encounter heavy opposition. "The chairman has already told me it won't fly," said Del. Richard R.G. Hobson (D-Alexandria).

The measure approved by the Senate imposes a five-year "sunset" clause requiring that the tax be re-evaluated after that time. Currently, three-fourths of the revenues from the statewide 4 percent sales tax go to the remainder to local governments.

"This is a workable approach to a practical problem," Hirst said of the tax-increase proposal before it was approved, 33 to 5.

Some legislators opposed to the measure said it was unfair to allow one part of the state (Northern Virginia) a power that other regions do not have.

In other action, the Senate passed a bill that would revise the state's sexual assault laws. Two controversial provisions - one that would eliminate marriage as a defense for rape and another that would make rape more serious if it was committed by a person in a "position of authority to the victim - had already been deleted from the original bill in order to make it more acceptabel to opponents.

The bill approved on a 32-to-6 vote, would shift the emphasis of the law from viewing it as a violent one. It would make sexual assault sex-neutral, so that raping a male would be a serious a crime as raping a female. The penalty for sodomy now is less than for rape.

It would classify, depending on the nature of the assault and on the type and amount of force involved. It would be more difficult to introduce testimony on the victim's prior sex life if the bill becomes law and justification for doing so would have to be presented first in a closed hearing rather than in open court.

The measure also would make it the policy of the state that all victims "shall be treated with dignity and respect at all times."

Most of the objections to the bill stemmed from the restrictions on use of a person's sexual history as evidence. The measure now goes to the House.

In another crime-related measure, the Senate passed for the third time a bill that would give judges, instead of juries, the right to sentence criminals, except murder cases involving the possible use of the death penalty.

The legislaion, introduced by Sen. Herbert H. Bateman (R-Newport News), was approved on a 20-to-19 vote and now goes to the House, which has killed similar measures.

Bateman said juries often do not know about a defendant's past criminal record or other background information that a judge could use in determing the proper sentence. Opponents contended there is no better way of sentencing than to let ordinary citizens decide the penalty for specific crime.

Virginia juries now set sentences after determing that a perosn is guilty of a crime, although judges can reduce sentences but not raise them.

As the Senate and House neared their self-imposed deadline yesterday for consideration of bills orginating in their respective chambers, there was the usual last-minute confusion brought on by the crush of legislation.

To the amazement of its supporters one controversial bill was temporarily approved by a Senate committee. The bills which would allow localities to decide whether to bargain collectively with public employes, was sent to the full Senate on an 8-to-7 vote in theCommerce and Labor Committee. That action brought shouts of jubilation from teacher and public employe representatives seated in the committee room.

But their victory was to be short-lived. Sen. Nathan Miller (R-Rockingham), whose unexpected affirmative vote had propelled the bill onto the Senate floor, rose to say he had made a mistake in voting for the bill and asked that it be sent to the committee.

"We have never killed a bill on the last day like this," Senate Leader Adelard L. Brault (D-Fairfax), said in the motion to opposing send the bill back for sure death in committee. But the motion passed, 25 to 14.

The Senate also voted 24 to 8 to ask President Carter, Congress and Health, Education and Welfare attacking the tabacco industry." This resolution refers to Califano's recently instituted $23 million antismoking campaign, to which Virginia tabacco growers take exception.

During its heavy calendar the House:

Passed and sent to the Senate a bill that would permit optometrists who completed a training program to use eyedrops when they examine their patients. Opthalmalogists - who unlike optometrists are medical doctors, had opposed earlier versions of the bill.

Approved and sent to the Senate a bill from $18,000 to $22,000 the salaries that members of some boards of supervisors acbe paid. The bill was offered by Del. Richard L. Seslaw (D.Fairfax). Fairfax County's supervisors are paid $15,000. The Seslaw bill does not affect the present $25,000 ceiling for chairman of the board.

Passed and forwarded to the Senate a bill that would permit Falls Church and Fairfax City voters to participate in any Fairfax County referendum on whether the proposed new courthouse should be built outside Fairfax City. The county is considering moving its entire governmental complex, now located in Fairfax City, to a less-congested part of the county.

Approved, on on 84-to-10 vote, a measure that would require starting with the class of 1981, that students pass a test before they could graduate from high school. But the bill does not require that students pass any test before being advanced from one grade to another.