Question

Henry is the unit of-
A. self-inductance or mutual inductance
B. e.m.f.
C. capacity
D. conductivity

Answer 1

Hint: One Henry is a unit of a physical quantity in a closed circuit where one Volt voltage is produced from the induced current of one Ampere. Consider a circuit in a varying magnetic field. The induced current in the circuit produces voltage. Find out the physical quantity which represents this.

Complete step by step answer:
Henry is a SI unit. It is abbreviated as H.
When a single coil experiences the effect of inductance, we have the effect of self-inductance. When the current in a coil changes, a magnetic field is induced due to change in the current. This magnetic field produces or induces a voltage in the same circuit. This voltage is called the self-induced voltage.
In case of two coils or conductors near each other, if the current changes in one of the conductors, then a magnetic field is induced. This induced magnetic field through the second conductor can produce or induce a current in the second coil. This induced current can produce a voltage in the second circuit.
This induced voltage is directly proportional to the change in current through the circuit. We can mathematically express it as,
$\begin{align}
  & {{V}_{L}}\propto \dfrac{di}{dt} \\
 & {{V}_{L}}=L\dfrac{di}{dt} \\
\end{align}$
Where L is the value of the inductance.
For a single circuit we have the self-inductance and if we have two coils then we will have the mutual inductance.
Henry is the SI unit of the self-inductance or the mutual inductance where, one henry can be defined as the inductance in a circuit where one-volt voltage induced by the flow of current of one ampere.

So, the correct answer is “Option A”.

Note: EMF or electromotive force is the voltage. The unit of emf is voltage. Capacity is the ability of a capacitor to store electric charge in it. The unit of capacity is Farad. Conductivity of a material can be defined as how easily that material lets the electric charge to flow through the material. The SI unit of conductivity is siemens per meter.