Does the v_type need to be in a separate table, yes or no please explain which normalization rule does is applied ? I want this table normalize upto 3NF.
Vechile
v_id (pk) | V_name | V_type
----------------------------------
v1 Ferrai car
v2 merto train
v3 City_bus bus
v4 Lamborgini car
v5 grey hound bus
As far as stands here, this table is normalized. It's legal to use strings like "car" or "metro" as primary key for a V_type table, or just as attributes of your vehicle table. Normalization would only be violated if you put additional attributes of V_type entity into the Vehicle table, e.g. an attribute public that determines whether it's public or private transport.
Even if you don't have such additional attributes, there might be a reason for separating the vehicles types into a table of their own. That way you can control which vehicle types may exist. In your current design, if someone enters a record like
v18 Mercedes cra
that would be accepted. If, however, you have a vehicle type table that contains entries only for valid vehicle types like car, metro, bus, and train, you can ensure by a foreign key constraint that the vehicle table will only reference those types.