Surinder Singh Dhillon, who is confined to a wheelchair, flashed a big smile to his mother, then shook hands with friends yesterday when he emerged from a 15-minute quiz on the fine points of American history before a U.S. Immigration and Naturalization Service official.

The quiz - actually a preliminary hearing to determine whether Dhillon, 30, is eligible to apply for U.S. citizenship - was his first formal step toward becoming a naturalized American.

By next February at the latest, Dhillon will take the oath of citizenship, according to John F. Gossart Jr., an immigration service attorney, who said he is virtually certain that Dhillon will be granted full citizenship.

Dhillon was one of 13 persons interviewed by immigration officials yesterday. And except for his physical disability, he was not much different from the rest.

"The Constitution requires that before a person can be granted citizenship he must be able to read, write and understand English," said Gossart. "Mr. Dhillon does them all quite well."

While other immigrants may seek U.S. citizenship in order to achieve success, Dhillon despite his handicap has in many ways already achieved the American dream of wealth and influence.

Last year his corporation, Rehab Group Inc., located in Arlington, grossed more than $4 million. The firm, of which Dhillon is president, currently employs some 300 people, 40 per cent of whom are handicapped.

A native of Simla, India, Dhillon came to the United States in 1964 at age 18 with his mother, Sukhbans K. Dhillon, a former member of the Indian foreign service, when she was assigned to the Indian Embassy in Washington.

A year later, Dhillon was driving to Pittsburgh to visit a friend when he crashed into another car that stopped ahead of him suddenly on a rainy evening.

He emerged from the wreck with a broken left leg.But the injury aggravated his acute rheumatioid arthritis and major complications set in.

For six years after the accident, Dhillon was in and out of hospitals for treatment. Repeated surgery could not correct his arthritic condition. His left side continued to wither.

But it was during these years of treatments and rehabilitation - often while he lay in bed - that Dhillon studied solid-state electronics and computer technology, and thought about the plight of the handicapped.

When he was finally able to sit up and manipulate the control of an electric wheelchair, he vowed that he would never be dependent on anyone again.

"The main thing I think about when I think of my past," he said yesterdy as he waited to be interviewed by immigration officials, "is that a person can make it if he's determined enough. The wheel-chir is as much of a barrier as you want to make it."

Dhillon, who goes wherever he wants to in his battery-powered wheelchair, is a minority business man who is rapidly moving into big business.

When his vocational rehabilitation was completed, Dhillon earned a living for a while as a consultant on computer technology and the needs of the handicapped.

He quickly used his consultant fees and formed his own business, Rehab Transportation Inc., which used vans to transport the handicapped. Then came Rehab Computer Inc., a company designed to train disabled persons in computer technology, and Micro-matics Systems, Inc., a microfilming company.

Today Dhillon's firm, which is devoted to the employment and development of services and products for the handicapped, covers everything from vocational skills training, expertise on disability research to training for the handicapped in independent living.

Dhillon said he has encounted some problems with larger firms who feel firms like his should not be able to get lucrative government contracts.

Dhillon said recently that his firm had about wrapped up a $5 million contract to provide training for handicapped employees of the Securities Exchange Commission in making microfilm and microfiche.

A large Virginia firm challenged the agency's procedures in awarding the contract to Rehab Group Inc. In the dispute the followed, the larger firm underbid Rehab Group Inc., which lost the contract.

"It seems that the big boys have a lot of influence and if they want to they can blow you out of the water," Dhillon said.

In January, Dhillon said, a television disco dance show that he is backing financially will go into production. He said the 13 shows, which he hopes to sell to either a major net-work or nearby television stations will be produced primarily by disabled persons.

"I would like to do more things of this kind to provide a way for the talents and skills of handicapped people to be used," said Dhillon, who said the television project will cost him between $140,000 and $150,000.

When Dhillon was disabled by the auto crash, his mother said she resigned her post with the Indian Embassy "to become his arms and legs." Mrs. Dhillon, 49, said she helped her son establish himself in business, and now she is the firm's chief executive officer and chairperson of the board of directors.

She also began proceedings yesterday to become an American citizen when her son does early next year.

"My son and I have adjoining offices," she said. "He is a sharp businessman. He likes to make quick decisions. I am more conservative and I try to oversee what he does.We work well together."

"I like the free enterprise system. I like what I'm doing," said Dhillon. "It's not just a question of making money, but the idea that Ican have an impact on the community on behalf of the handicapped."