Physics Trivia Questions and Answers

25 questions on Physics, each with the answer and a short explanation. Part of the Science set in Rapid Fire Trivia, which holds 2,000 questions across 5 topics.

All 25 questions, with answers

1. 1Which color of visible light has the longest wavelength?

   AnswerRed

   Red light has a longer wavelength and lower frequency than the other visible colors.

2. 2An object has balanced forces acting on it. Which motion is possible?

   AnswerConstant velocity

   Zero net force means zero acceleration, so rest or constant straight-line motion can continue.

3. 3Static electricity often builds when materials transfer which particles?

   AnswerElectrons

   Friction can move electrons between surfaces, leaving one negatively charged and the other positively charged.

4. 4How does a kaleidoscope create repeating patterns?

   AnswerMultiple reflections between mirrors

   Angled mirrors reflect the same colored pieces repeatedly, producing symmetrical visual patterns.

5. 5Why does an electromagnet stop attracting iron after its current is switched off?

   AnswerIts magnetic field collapses

   An electromagnet depends on electric current to create and sustain its magnetic field.

6. 6Why does cooking oil usually float on water?

   AnswerOil is less dense than water

   A liquid with lower density floats above a denser immiscible liquid under gravity.

7. 7How does a mirror form an image?

   AnswerBy reflecting light

   A smooth mirror redirects incoming light in an orderly way, producing a recognizable image.

8. 8How does a plane mirror usually show an object?

   AnswerUpright and the same size

   A plane mirror forms a virtual image with unchanged height and reversed left-right appearance.

9. 9Which material is normally the best electrical insulator?

   AnswerDry ceramic

   Ceramics contain few mobile charge carriers, so electric current passes through them poorly.

10. 10What happens to water pressure as a swimmer goes deeper?

    AnswerIt increases

    Deeper water has more fluid above it, so the surrounding pressure becomes greater.

11. 11Why can a rubbed balloon attract tiny pieces of paper?

    AnswerStatic electric charge polarizes the paper

    Transferred charge on the balloon rearranges charges in nearby paper, creating a weak attractive force.

12. 12Why do airbags reduce injury during a collision?

    AnswerThey increase the time over which a passenger stops

    A longer stopping time reduces the average force needed to change the passenger’s momentum.

13. 13How does increasing the current through a simple electromagnet usually affect it?

    AnswerIt makes the magnetic field stronger

    More current produces a stronger magnetic field around the coil, within the material’s practical limits.

14. 14Which instrument shows how fast a car is moving?

    AnswerSpeedometer

    A speedometer displays instantaneous speed, while an odometer records the total distance travelled.

15. 15Which camera control sets how long light reaches the sensor?

    AnswerShutter speed

    The shutter’s open time determines the duration of the camera sensor’s exposure to light.

16. 16Why does a vacuum cleaner pull dust into its hose?

    AnswerOutside air moves toward a lower-pressure region

    A fan lowers pressure in the hose, so surrounding air carries dust inward.

17. 17Which force pulls a dropped apple toward Earth?

    AnswerGravitational force

    Earth’s gravity attracts masses toward its center and accelerates unsupported objects downward.

18. 18A guitar string produces sound after it does what?

    AnswerVibrates

    The vibrating string disturbs surrounding air, creating sound waves that reach the listener.

19. 19Why does an opaque object cast a shadow?

    AnswerIt blocks light

    Shadows form where an object prevents light from reaching a surface behind it.

20. 20When bicycle brakes slow a wheel, most of its kinetic energy becomes what?

    AnswerThermal energy

    Friction in the brake pads and disc or rim converts motion into heat.

21. 21What happens to a guitar string’s pitch when the string is tightened?

    AnswerThe pitch rises

    Greater tension makes the string vibrate faster, increasing its frequency and therefore its perceived pitch.

22. 22Why can a metal spoon become hot when left in a saucepan?

    AnswerThermal energy conducts through the metal

    Mobile electrons and vibrating atoms transfer thermal energy efficiently along the metal spoon.

23. 23How does a shadow usually change when an object moves closer to a small light source?

    AnswerIt becomes larger

    Moving nearer the source lets the object block a wider cone of diverging light rays.

24. 24A wheelbarrow is commonly classified as which type of lever?

    AnswerSecond-class lever

    Its load lies between the wheel’s fulcrum and the effort applied at the handles.

25. 25Why does a stretched rubber band return toward its original shape?

    AnswerElastic forces oppose the deformation

    Deforming the polymer chains stores elastic energy that drives the band back toward equilibrium.