Picat General Science 5 โ Questions and Answers
Question 1: What is the SI unit of electrical resistance?
- Ampere
- Volt
- Ohm (Correct answer)
- Watt
Correct answer: Ohm
The ohm (ฮฉ) measures electrical resistance and is named after physicist Georg Simon Ohm.
Question 2: Which type of energy is stored in a compressed spring?
- Kinetic energy
- Thermal energy
- Chemical energy
- Elastic potential energy (Correct answer)
Correct answer: Elastic potential energy
A compressed or stretched spring stores elastic potential energy, which is released when the spring returns to its natural length.
Question 3: Newton's Third Law of Motion states that for every action there is:
- A proportional reaction in the same direction
- An equal and opposite reaction (Correct answer)
- A greater reaction in the opposite direction
- No reaction in a vacuum
Correct answer: An equal and opposite reaction
Newton's Third Law states that forces always come in equal and opposite pairs โ if A pushes B, B pushes back on A with the same magnitude.
Question 4: What is the correct formula for calculating speed?
- Speed = Force ร Time
- Speed = Mass ร Acceleration
- Speed = Distance รท Time (Correct answer)
- Speed = Work รท Force
Correct answer: Speed = Distance รท Time
Speed is defined as the distance traveled divided by the time taken to travel that distance.
Question 5: Which type of wave does sound travel as through air?
- Transverse wave
- Electromagnetic wave
- Longitudinal wave (Correct answer)
- Surface wave
Correct answer: Longitudinal wave
Sound travels as a longitudinal wave, where particle displacement is parallel to the direction of wave propagation.
Question 6: What is the approximate speed of light in a vacuum?
- 300,000 km/s (Correct answer)
- 30,000 km/s
- 3,000,000 km/s
- 186 km/s
Correct answer: 300,000 km/s
Light travels at approximately 300,000 kilometers per second (about 186,000 miles per second) in a vacuum.
Question 7: Which of the following is an example of a chemical change rather than a physical change?
- Ice melting into water
- A piece of paper being torn
- Iron rusting on a fence (Correct answer)
- Glass breaking into pieces
Correct answer: Iron rusting on a fence
Rusting is a chemical change because iron reacts with oxygen and water to form iron oxide, a new substance with different properties.
Picat General Science 5
What is the SI unit of electrical resistance?