Test your knowledge of electric current, series-parallel circuits, power, and energy with these interactive puzzles!
Puzzle 1: Define electric current.
Hint: Current is related to the flow of charge through a conductor.
Answer: Electric current is the rate of flow of electric charge through a conductor.
Puzzle 2: What is the SI unit of electric current?
Hint: It's named after a famous scientist.
Answer: The SI unit of electric current is the ampere (A).
Puzzle 3: Calculate electric energy consumed when a heater of 1kW used for 1 hour?
Hint: E( in kWh) = P(in kW) x Time ( in hour).
Answer: 1 kWh.
Puzzle 4: How many electrons together constitute one coloumb of charge ?
Hint: charge on 1 electron is - 1.6 x 10-¹⁹ C.
Answer: 625 x 10¹⁸ electrons.
Puzzle 5: What is the relationship between kilowatt-hours (kWh) and joules?
Hint: 1 kWh is the energy consumed by a 1 kW device running for 1 hour.
Answer:1kWh= 3.6 x 10⁶J.
Puzzle 6: What is the formula for electrical power?
Hint: Power is the rate at which work is done or energy is transferred.
Answer: The formula for electrical power is P = VI, where P is power, V is voltage, and I is current.
Puzzle 7: How is electrical power related to voltage and current?
Hint: Use the formula P = VI.
Answer: Electrical power is directly proportional to both voltage and current. The higher the voltage or current, the higher the power.
Puzzle 8: What is the effect of long-distance transmission on power loss?
Hint: Power loss increases with resistance and current.
Answer: Power loss during transmission increases with the distance and is proportional to the square of the current (P = I² R).
Puzzle 9: What is the advantage of using high-voltage transmission over long distances?
Hint: Higher voltage means lower current for the same power.
Answer: High-voltage transmission reduces power loss because it allows for lower current, and since power loss is proportional to I², this reduces losses.
Puzzle 10: If a device uses 2 kWh of energy in one hour, how much energy is used in joules?
Hint: 1 kWh= 3.6 x 10⁶J
Answer: The energy used is 2kWh= 2x3.6x 10⁶J= 7.2 x10⁶J.
