Using the definition of the volt from electromagnetic induction, the time required for one weber (1 Wb) of magnetic flux to cut a conductor and induce one volt (1 V) is equal to what duration?

Introduction / Context:
The SI definition of the volt ties electrical potential to the rate of change of magnetic flux linkage. One volt equals one weber per second when induced by electromagnetic induction. This question checks recognition of that fundamental unit relationship.

Given Data / Assumptions:

• Flux linkage is changing uniformly.
• Induced emf due to cutting or linking flux (Faraday’s law).
• Single-turn equivalence for simplicity.

Concept / Approach:
Faraday’s law (magnitude): emf = dΦ/dt for a single turn. If emf = 1 V and the total change in flux is 1 Wb, then the time required is t such that 1 V = 1 Wb / t, giving t = 1 s. Rotational “revolutions” do not directly define voltage unless related to flux change per unit time.

Step-by-Step Solution:
Set emf = 1 V.Let ΔΦ = 1 Wb over interval t.Then 1 = 1 / t → t = 1 s.Therefore, the required time is one second.

Verification / Alternative check:
In rotating machines, increasing speed reduces the time for a given flux change, increasing induced voltage proportionally—consistent with 1 V = 1 Wb/s as the base relationship.

Why Other Options Are Wrong:

• Revolutions are mechanical counts, not time units; voltage depends on flux change rate, not merely turns.
• One millisecond or one minute contradicts the 1 Wb per 1 V requirement unless emf differs from 1 V.

Common Pitfalls:

• Confusing webers (flux) with tesla (flux density) and seconds (time).
• Forgetting the turn count N scales emf; here we reference 1 turn equivalence for clarity.

Final Answer:
one second