U can say:你叫什么名字？ but u can't say:你叫吗？ Because 你叫吗 doesn't have the object.

You can ask 你是谁(who are you?) or你叫什么名字？(what is your name?)=你叫什么？ But 你叫吗is wrong.

no, you cant. because that sentence doesnt make sense. 叫 means call 什么means what. 吗 just a symbol of question. hope that can help you

“你叫” is an uncomplete sentence. Both "你叫什么?" and "你叫什么名字？" are correct.

If you want other's name, you can use "您贵姓？怎么称呼？”，which is polite and formal