Energy: Forms and Transfer — Answer Key
Part A: Multiple Choice
Circle the best answer for each question.
1. A solar-powered lamp captures sunlight during the day and lights a room at night. What is the FIRST energy form in this system?
A) Light energy from the sun
B) Electrical energy in wires
C) Heat in the panel
D) Sound from the bulb
Grade 4 students learn that solar systems start with light energy from the sun. The panel captures sunlight before any other transfer happens in the chain.
2. After the solar panel captures sunlight, what is the NEXT step in the system?
A) Light becomes sound
B) Light is stored as electrical energy in a battery
C) Light becomes potential energy
D) Light disappears completely
Grade 4 science teaches that solar panels transform light into electrical energy. Batteries then store that electrical energy until it is needed at night.
3. When the lamp turns on at night, what energy transformations happen at the bulb?
A) Sound becomes light
B) Electrical energy becomes light and heat
C) Heat becomes electrical
D) Potential becomes kinetic
Grade 4 students learn that bulbs transform electrical energy into light energy and heat. Both outputs come from the same input of electricity.
4. Which best describes the full energy path in this system?
A) Sound to electrical to light
B) Light to electrical to light and heat
C) Heat to motion to sound
D) Potential to kinetic to potential
Grade 4 science traces the chain: sunlight (light) becomes electrical energy in the panel and battery, then transforms to light and heat at the bulb.
Part B: Fill in the Blank
Write the correct answer on each line.
1. In a solar lamp system, the original source of energy is the sun.
Grade 4 students learn that the sun is the starting point of solar systems. All other energy in this chain originally came from sunlight.
2. The solar panel transforms light energy into electrical energy.
Grade 4 science describes how solar cells convert light into electrical current. This is the first transformation step in the system.
3. Electrical energy is stored in a battery for use later when the sun is not shining.
Grade 4 lessons teach that batteries store electrical energy. This lets the system save daytime sunlight for nighttime use.
4. When the bulb glows, electrical energy transforms into both light and heat energy.
Grade 4 students learn that bulbs always produce both light and heat. The heat is wasted energy that escapes into the surrounding air.
5. Energy in this system is never destroyed; it only changes from one form to another.
Grade 4 science introduces conservation of energy. In every step of a system, energy changes form but is never lost or destroyed.