Which of the following factors will increase the strength of the magnetic field at the center of a current-ca… - RRB Nsg. Superintendent-2026 (Shift -1st)

RRB Nsg. Superintendent-2026 (Shift -1st)

General Knowledge

Easy

Appeared in: RRB Nsg. Superintendent-2026 (Shift -1st)

Explanation

The strength of the magnetic field at the center of a current-carrying circular loop is directly proportional to the number of turns in the loop.
This relationship is described by the formula: B = (μ₀ × N × I) / (2 × R), where B is the magnetic field, N is the number of turns, I is the current, and R is the radius.
Increasing the number of turns (N) effectively sums the magnetic fields from each individual loop, resulting in a stronger overall magnetic field at the center.

Option A: Changing the orientation of the loop from horizontal to vertical only changes the direction of the magnetic field vector, not its magnitude or strength.
Option B: The magnetic field strength is directly proportional to the current (I). Therefore, decreasing the current will weaken the magnetic field, not strengthen it.
Option D: The magnetic field strength is inversely proportional to the radius (R) of the loop. Increasing the radius spreads the field out, causing its strength at the center to decrease.

Visual 1: Diagram - A diagram showing a current-carrying circular loop with magnetic field lines. Arrows should indicate the direction of current (I) and the resulting magnetic field (B) at the center, illustrating the right-hand thumb rule.
Visual 2: Infographic - An infographic displaying the formula B = (μ₀ × N × I) / (2 × R) and explaining what each variable represents and its relationship to B.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Factors affecting the magnetic field of a current-carrying circular loop as background academic context rather than a clinical decision trigger.
While this is a physics concept, understanding electromagnetism is fundamental to the technology behind Magnetic Resonance Imaging (MRI).
MRI machines use powerful electromagnets, which are essentially large coils with many turns of wire, to generate a very strong and stable magnetic field required for imaging (SRC_2).
The strength of this magnetic field is critical for aligning hydrogen atoms in the body. A stronger magnet yields a better signal, leading to higher quality images (SRC_1).

How to Approach the Question

This is a factual recall question based on physics principles.
First, identify the core concept: the relationship between a current-carrying circular loop and the magnetic field it produces.
Recall the formula for the magnetic field at the center of a circular loop: B = (μ₀ × N × I) / (2 × R).
Analyze how each variable in the formula affects the magnetic field strength (B). Note that B is directly proportional to N (number of turns) and I (current), and inversely proportional to R (radius).
Evaluate each option against the formula: Increasing N increases B. Decreasing I decreases B. Increasing R decreases B. Changing the plane affects direction, not strength.
Conclude that increasing the number of turns is the only option that increases the magnetic field strength.

Concept Tested & Keywords

Concept Tested: Factors affecting the magnetic field of a current-carrying circular loop
Stem keywords: magnetic field, strength, current-carrying circular loop, increase
Lead-in keywords: Which of the following
Negative lead-in flag: false

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