Question

electric & magnetic forces
solenoid a
copper wire only
current: 6 amps
solenoid b
copper wire only
current: 8 amps
solenoid c
copper wire + iron core
current: 6 amps
solenoid d
copper wire + iron core
current: 8 amps
based on the strength of the magnetic fields they produce, arrange the solenoids from strongest to weakest.
solenoid a solenoid b solenoid c solenoid d
□ > □ > □ > □

Explanation:

Step1: Recall factors affecting solenoid magnetic field strength

The strength of a solenoid's magnetic field depends on: 1) Current (higher current → stronger field), 2) Presence of a ferromagnetic core (like iron, increases strength), 3) Number of turns (more turns → stronger, but here A and B have same turns; C and D same turns).

Step2: Analyze each solenoid

• Solenoid D: Copper Wire + Iron Core, Current = 8 A.
• Solenoid C: Copper Wire + Iron Core, Current = 6 A.
• Solenoid B: Copper Wire Only, Current = 8 A.
• Solenoid A: Copper Wire Only, Current = 6 A.

Step3: Rank by strength

1. Core (iron) increases strength. Among C and D, D has higher current (8 A > 6 A) → D > C.
2. Among A and B (no core), B has higher current (8 A > 6 A) → B > A.
3. A core - equipped solenoid (C or D) is stronger than non - core (A or B) with same current. So D (core, 8 A) > C (core, 6 A) > B (no core, 8 A) > A (no core, 6 A).

Answer:

Solenoid D > Solenoid C > Solenoid B > Solenoid A