คำถามทบทวนความรู้

เพิ่มเป็นสี่เท่า

• Define the system and useful output before calculating efficiency. Doubling speed quadruples kinetic energy at constant mass. Power describes transfer per time, not total energy.

60 %

• Appropriate relation; consistent substitution; correct result; meaningful unit and interpretation.

พลังงานเปลี่ยนการจัดเรียงของอนุภาค

• Temperature relates to particle motion in a model; internal energy includes kinetic and potential contributions. During a change of state, energy can change particle arrangements rather than temperature.

3000 J

• Appropriate relation; consistent substitution; correct result; meaningful unit and interpretation.

เชื่อมต่อขนานกับตัวต้านทาน

• Current is the same through components in series. Potential differences add around the series path. In parallel, branches share the same potential difference, while branch currents sum at a junction.

30 Ω

• Appropriate relation; consistent substitution; correct result; meaningful unit and interpretation.

เพิ่มเป็นสองเท่า

• State which quantities stay fixed. A pressure-volume relation requires consistent units and a fixed temperature. The kelvin-based temperature ratio is an extension only where the course explicitly specifies it.

200 kPa

• Appropriate relation; consistent substitution; correct result; meaningful unit and interpretation.

ค่านับที่วัดได้ลบด้วยค่าพื้นหลังในช่วงเวลาเท่ากัน

• Subtract background counts measured over the same time interval. Distinguish irradiation from contamination. Shielding, distance and reduced exposure time can reduce risk under a school-controlled procedure.

20 ครั้ง/นาที

• Appropriate relation; consistent substitution; correct result; meaningful unit and interpretation.

เวลาหยุดนานขึ้น

• Impulse equals momentum change. Increasing stopping time for the same momentum change reduces average force. Identify external forces before applying momentum conservation.

6 กก.·ม./วินาที

• Appropriate relation; consistent substitution; correct result; meaningful unit and interpretation.

การแทนที่

• The gradient of a displacement-time graph is velocity. The area under a velocity-time graph gives displacement. A constant-acceleration formula is valid only when its assumption is justified.

2 m/s²

• Appropriate relation; consistent substitution; correct result; meaningful unit and interpretation.

ความถี่

• At a boundary, frequency stays fixed by the source. A change of speed changes wavelength. Refraction follows from speed differences; angles are measured from the normal.

2 m/s

• Appropriate relation; consistent substitution; correct result; meaningful unit and interpretation.

การเชื่อมโยงฟลักส์ที่เปลี่ยนแปลง

• Changing field strength, coil area, orientation or relative motion can change flux linkage. Lenz law describes an induced effect opposing the change producing it, consistent with energy conservation.

5 V

• Appropriate relation; consistent substitution; correct result; meaningful unit and interpretation.

ลดลงเหลือหนึ่งในสี่

• For isotropic emission without absorption, flux follows an inverse-square relationship with distance. Observed brightness alone therefore cannot establish luminosity.

2

• Appropriate relation; consistent substitution; correct result; meaningful unit and interpretation.