BERLIN – Brahms, beer, and Beethoven are German, but can a Muslim head scarf be German too?

Muslim communities throughout this country are beginning to wonder. What it means to be German is an excruciating riddle, not something casually broached in a cafe. But efforts to sharpen national identity through new citizenship tests have caused a furor over accusations that Muslims are being unfairly targeted for exclusion by questions concerning head scarves, arranged marriages, homosexuality, and Israel’s right to exist.

The tests are the latest point of contention in a cultural battle over the integration of millions of Muslims on a continent wary of terrorist attacks, such as the ones in London and Madrid, Spain. They are another indication that Europe is struggling with how to temper nationalism and anxiety while defining citizenship for an immigrant Muslim population restless over what it views as generations of discrimination.

The tests are idiosyncratically German, demanding a breadth of arcane knowledge that might prove difficult for even the most patriotic Bavarian soul. Questions include details on German mountain ranges, a 19th century seaside painting, and the discovery by a German scientist who, outside advanced physics classes, has long since lost his cachet. One can almost hear the collective riffle of encyclopedia pages in living rooms and study halls across the country.

But it is the questions layered between the inquiries on German geography, history and music that have agitated Muslims. A test in the state of Baden-Wuerttemberg and a proposed exam in the state of Hesse gauge Muslim sensitivities in an attempt to filter out religious conservatives and potential extremists.

Baden-Wuerttemberg requires an education course and a 30-question oral test to determine whether an immigrant supports issues such as women’s rights and religious diversity. The test is graded at the discretion of the interviewer. Some state officials suggest that the exam may be illegal because a provision allows citizenship to be revoked if it is found that an applicant masked his religious or fundamentalist tendencies.

Question 27 is typical of the test’s tone: “Some people consider the Jews responsible for all the evil in the world and even claim they are behind the September 11 attack in New York. What do you think about such suggestions?”

The Hesse exam – expected to be approved this year – lists 100 questions, most of them on German history and culture. About 10 queries are aimed at Muslims, including whether a woman should be allowed in public unaccompanied by a male relative. Islamic organizations have cautioned immigrants not to give answers on their religious and personal beliefs. One satirical German Web site quipped that Muslims failing the test would be interrogated and flown out of the country on a CIA plane.

“These tests are presupposing, negative, and anti-Islamic,” said Eren Unsal, a sociologist and member of a German-Turkish lobbying and educational organization based in Berlin, the Turkish Union.” What we’re seeing is a more restrictive immigration policy whose face is anti-Muslim.

“This is rooted in September 11 and the attacks in Europe,” Ms. Unsal added. “I think these citizenship tests are the destructive result of a wider cultural debate. They’re looking for scapegoats.”

Citizenship is granted to immigrants by the German states in which they live. The governments in Hesse and Baden-Wuerttemberg are controlled by conservatives; other right leaning states are also considering tougher citizenship requirements. Momentum is growing for a uniform national citizenship law – a prospect that would ignite partisan debate between the coalition government of left-leaning Social Democrats and Chancellor Merkel’s conservative Christian Democrats.

Mrs. Merkel favors more scrutiny of foreigners. “Citizenship can’t be granted in passing,” the chancellor said recently. In 2005, Germany toughened its immigration law by requiring new arrivals to attend 630 hours of language, history, and cultural courses.

The European Union is contemplating adopting an “integration contract” for immigrants. The Interior ministers of Germany, Poland, France, Spain, Britain and Italy support the idea. Germany’s interior minister, Wolfgang Schaeuble, said the continent must lay out “the rights and obligations” for new arrivals.

“A true Muslim believer can answer these questions and not feel singled out,” a Christian Democratic member of Parliament, Eckart von Klaeden, who favors more rigorous citizenship questionnaires, said.

“These tests are designed to keep the extremists out, not just Islamic extremists but right- and left-wing extremists too,” Mr. Von Klaeden added. “Being a citizen means to take part and live under our laws and share our principal values.”

Most of Germany’s 3 million Muslims are Turks whose parents and grandparents arrived as guest workers beginning in the 1960s. Failed integration policies and an insular Turkish population have turned many cities into multicultural yet demarcated societies, with unspoken borders between ethnic Turks and Germans.

These lines were being drawn when sociologist Ms. Unsal’s mother left the Anatolian plains of Turkey decades ago to work in a German lightbulb factory. Ms. Unsal was a child when she and her father, a tailor, followed.

“I was 5 years old when I got here. I didn’t feel like a migrant back then,” a German citizen fluent in the language of her adopted country, Ms. Unsal, said. “But although I’ve fulfilled all of what this country has asked of me to integrate, I still don’t feel part of society. Germans don’t see me as part of their society. I get these kinds of signals 20 times a day.”

The situation has intensified since Ms. Unsal’s childhood. The surge of radical Islam coincided with German fears over high unemployment and the shrinking of the traditional welfare state. Germany’s birthrate is the country’s lowest since World War II, and it has one of the fastest-growing aging populations in the world. The country knows it will eventually need new blood to fill jobs and support social programs, but it is increasingly suspicious of foreigners.