PhysicsRankPREVIEWTry a problem

THE PRACTICE STUDIO

Go slowly. Ask why. Make it yours.

PRACTICE · MEMBERSAdvanced · Single correct

PRACTICE / Velocity selector

Selection followed by curvature

Positive ions pass undeflected through a selector with E=6.0×10⁴ V/m and B_s=0.20 T. They then enter a separate magnetic-only region normally to B_a=0.50 T and follow radius 0.012 m. Each ion has charge +1.60×10⁻¹⁹ C.

What mass follows from these observations?

Organize the givens & assumptions
  • Selector: E=60000 V/m, B_s=0.20 T
  • Analyser: B_a=0.50 T, r=0.012 m
  • Charge: +1.60×10⁻¹⁹ C

No speed change between regions; nonrelativistic ions; uniform fields; analyser entry perpendicular to its field.

  1. A1.28×10−27 kg1.28\times10^{-27}\ \mathrm{kg}
  2. B3.20×10−27 kg3.20\times10^{-27}\ \mathrm{kg}
  3. C6.40×10−27 kg6.40\times10^{-27}\ \mathrm{kg}
  4. D2.88×10−16 kg2.88\times10^{-16}\ \mathrm{kg}

Try it on paper first. Free sample problems in every collection include the complete reasoning: find one in this collection →