At fixed charge, mass, and speed, stronger magnetic field means smaller radius. Exact arithmetic here means exact results for the stated model inputs; measured inputs still carry uncertainty and significant-figure limits.

highlighted = computed this step

The weaker field has the wider orbit

At field 2 tesla, the checked gyro radius is 6 meters.

B=2 Tr=6 mB=2\ \text{T}\Rightarrow r=6\ \text{m}
Wider orbitThe weak-field radius is the comparison case.chargeradiusvFq=2 Cv=3 m/sB=2 Tm=8 kgr=6 mqvB=12 Nmv2/r=12 NturnRate=1/2 1/s

Doubling the field tightens the orbit

At field 4 tesla with the same charge, speed, and mass, the radius drops to 3 meters.

B=4 Tr=3 mB=4\ \text{T}\Rightarrow r=3\ \text{m}
Stronger field tightens orbitThe field change is structural in the checked ledger.chargeradiusvFq=2 Cv=3 m/sB=4 Tm=8 kgr=3 mqvB=24 Nmv2/r=24 NturnRate=1 1/s