Magnetic force on a moving charge and on a wire
Grade 11 Science Worksheet - Challenge Me
Circle the best answer, or write your answer on the line.
A 20 g metal rod 0.5 m long lies across a 0.4 T field, level, at right angles. What current makes the magnetic force equal its weight, to 0.01 A, Esme?
A student says a magnetic field speeds up any charge moving through it. Which reply fits OpenStax, Luz?
- Yes; a stronger field speeds it up more
- No; the force is sideways, so the speed stays the same
- Yes; the force pushes the charge along its path
A student says an electron and a proton moving the same way through a field feel forces the same way. Which reply fits OpenStax, Milo?
- No; their forces point opposite ways
- Yes; the field pushes each one along its path
- Yes; both charges feel the same force direction
A student says a wire lying along the field lines feels the biggest force. Which reply fits F = IlB sin θ, Noah?
- No; a wire along the field feels zero force
- Yes; and that force points along the wire
- Yes; the force is biggest along the field, where the lines guide it
A proton's speed doubles in the same field. What happens to the radius of its circle, by Pia's reading (OpenStax)?
- It halves
- It doubles
- It stays the same
The field around a moving proton doubles. What happens to the radius of its circle, by Ren's reading (OpenStax)?
- It becomes 4 times smaller
- It halves
- It doubles
A proton moves at 2 × 10⁶ m/s across a 0.5 T field. About what radius is its circle, Tala? m = 1.67 × 10⁻²⁷ kg, q = 1.60 × 10⁻¹⁹ C.
- About 42 cm
- About 0.42 cm
- About 4.2 cm
A 25 cm wire carries 4 A at right angles to a 0.3 T field. What force acts on it, Zee?
- 0.3 N
- 30 N
- 0 N
The same 25 cm wire with 4 A is turned to 30° from the 0.3 T field. What force acts on it now, Ari?
- 0.26 N
- 15 N
- 0.15 N
A 40 cm wire carries 5 A at 60° to a 0.2 T field. About what force acts on it, Bo?
- About 0.35 N
- About 35 N
- About 0.2 N