What is the SI unit of electric current?

Appeared in: RRB Nsg. Superintendent-20 July 2019 (Shift-1)

Explanation

Ampere (A) is the base unit of electric current in the International System of Units (SI).
It is defined as the flow of one Coulomb of charge per second (1 A = 1 C/s).
Electric current measures the rate at which electric charge flows past a point in a circuit.

Option A: Joule (J) is the SI unit of energy or work, not electric current.
Option B: Gauss (G) is the unit of magnetic induction in the CGS system, not the SI unit of electric current. The SI unit for magnetic induction is the Tesla (T).
Option D: Henry (H) is the SI unit of electrical inductance, which relates to how a circuit stores energy in a magnetic field.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain SI unit of electric current as background academic context rather than a clinical decision trigger.
Understanding basic electrical units is fundamental in healthcare for operating and troubleshooting medical equipment like ECG machines, defibrillators, pacemakers, and infusion pumps, all of which rely on controlled electrical currents.
In procedures like electroconvulsive therapy (ECT), the stimulus is delivered and measured in terms of charge (millicoulombs) and current (Amperes), directly impacting treatment efficacy and safety.
What if the question asked for the unit of electrical charge? The answer would be the Coulomb (C), which is related to the Ampere by the formula: Charge (Coulombs) = Current (Amperes) × Time (seconds).

How to Approach the Question

This is a factual recall question from basic physics.
Identify the core concept being asked: the SI unit for 'electric current'.
Scan the options and recall the definition for each unit.
Ampere is the standard unit for electric current.
Joule is for energy, Gauss for magnetic induction (CGS), and Henry for inductance. Therefore, Ampere is the correct choice.

Concept Tested & Keywords

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Practise the full RRB Nsg. Superintendent-20 July 2019 (Shift-1)

Attempt every question from this paper in a timed mock, then review the full solution for each one.