How rapid Norwegian mobilization could have disrupted Operation Weseruebung

Could Norway realistically have mobilized and resisted the German invasion in April 1940?

Yes; an immediate alert after the invasion of Denmark could have mobilized the country before Germany executed its threatened air attack or secured its landings.

Norway possessed radio, telegram, telephone, postal, and local networks capable of spreading a mobilization order within hours. The government's fear that Oslo could immediately be destroyed from the air was largely self-generated, because Germany first needed Danish airfields to mount the threatened heavy raid. Alert coastal defences could have denied landings and forced German ships to withdraw toward the Royal Navy.