State the type of voice of the following sentence: 

An essay will be written by Sahil.

Active and Passive are the two voices of a transitive verb, which is a verb with an object. The verb is considered to be in the Active Voice when the subject of the verb also carries out the action. The verb is considered to be in the passive voice when the verb's subject receives the action it refers to. The verb's voice indicates whether or not the subject of the sentence is the one carrying out the activity that the verb denotes. It is necessary to identify the (S+V+O) Subject, Verb, and Object of the sentence. The active sentence's object becomes the passive sentence's subject. In the given sentence 'essay' is the subject. 'Written' is the verb or action. 'Sahil' is the object. In a passive sentence, the subject is having something done to it; hence we can say that the given sentence is in the passive voice.