Electricity, Magnetism & Light — Chapter quiz · Science 6: Matter, Energy & Earth Systems, Grade 6
How do fields, circuit paths, and light models explain observable changes? Which modeled circuit keeps lamp B available when lamp A is switched off, and what does the evidence not show?
Problem 1
- Rubbing creates electric charge from nothing.
- net charge: The imbalance between positive and negative charge in the chosen system.
- Attraction always proves two objects have opposite net charges.
- Every classroom model reproduces reality exactly.
Answer and explanation
net charge: The imbalance between positive and negative charge in the chosen system.
The imbalance between positive and negative charge in the chosen system. A has ten positive and eight negative units, a net positive two. B has ten positive and twelve negative, a net negative two. The combined twenty positive and twenty negative units remain; charge is transferred, not created. These are model units, not measured coulombs or a rule for every rubbed material.
Problem 2
Answer and explanation
No. Polarization can shift the interaction without requiring an opposite total net charge. Explain the modeled distribution rather than infer net charge from attraction alone.
Compare the scientific meaning and reasoning after an independent attempt. A different accurate supported response can be correct; human review is required.
Problem 3
- A picture of a closed circuit proves a real device is safe and functioning.
- The lamp consumes the charge, leaving none in the return path.
- circuit: A connected path supporting charge flow and energy transfer under stated conditions.
- Every classroom model reproduces reality exactly.
Answer and explanation
circuit: A connected path supporting charge flow and energy transfer under stated conditions.
A connected path supporting charge flow and energy transfer under stated conditions. The parallel branch design provides the modeled independent control: opening A does not interrupt B’s complete path. The common switch can still stop both. The records do not establish equal brightness, battery lifetime, or a safe real construction; those require a rated design and further evidence.
Problem 4
Answer and explanation
Inspect an approved kit’s contacts and source condition under adult guidance, or evaluate those possibilities in the supplied record. A complete drawing does not establish that every actual component functions.
Compare the scientific meaning and reasoning after an independent attempt. A different accurate supported response can be correct; human review is required.
Problem 5
- Every classroom model reproduces reality exactly.
- Every metal must be strongly attracted by a magnet.
- Dividing a bar magnet creates an ordinary magnet with only one pole.
- magnetic field: A representation of magnetic interaction around magnets or electric currents.
Answer and explanation
magnetic field: A representation of magnetic interaction around magnets or electric currents.
A representation of magnetic interaction around magnets or electric currents. The recorded holding count decreases as gap increases under this method. At 2 cm the mean is 5 clips and the range 4–6. Clip count is a practical proxy, not force in newtons, and these three distances do not establish an exact mathematical law or prove the field stops beyond 3 cm.
Problem 6
Answer and explanation
No. Metals differ in magnetic response, and the method has limits. Attraction is not a universal test for all metal identity.
Compare the scientific meaning and reasoning after an independent attempt. A different accurate supported response can be correct; human review is required.
Problem 7
- normal: A line perpendicular to a surface at the point being considered.
- Reflection angles are defined from the surface rather than the normal.
- A visible object must generate its own light.
- Every classroom model reproduces reality exactly.
Answer and explanation
normal: A line perpendicular to a surface at the point being considered.
A line perpendicular to a surface at the point being considered. The correct reflected angle is 40° from the normal and 50° from the surface. Drawing 40° from the surface makes it 50° from the normal, so the mismatch comes from the reference line. These are ideal ray-model angles, not a record of an actual mirror trial.
Problem 8
Answer and explanation
No. Source–object–screen distances and source size affect shadow geometry. Check those conditions before claiming a change in the object.
Compare the scientific meaning and reasoning after an independent attempt. A different accurate supported response can be correct; human review is required.
Problem 9
- Every ray must bend sideways at every transparent boundary.
- refraction: A change in light propagation speed at a medium boundary, commonly with oblique bending.
- An object appears the same color under every possible light source.
- Every classroom model reproduces reality exactly.
Answer and explanation
refraction: A change in light propagation speed at a medium boundary, commonly with oblique bending.
A change in light propagation speed at a medium boundary, commonly with oblique bending. The ray bends toward the normal because 22° is less than 35° in this air-to-water model. The card appears dark because the red-only source supplies no blue for it to reflect. These diagrams omit detailed wavelength response, intensity, and actual material variation; they are not universal measurements of every card or liquid.
Problem 10
Answer and explanation
A ray traveling directly along the normal can change speed without changing direction. Refraction’s speed change and oblique bending must be distinguished.
Compare the scientific meaning and reasoning after an independent attempt. A different accurate supported response can be correct; human review is required.