Advertisements
Advertisements
Question
Define electric current and give its unit.
Solution
Current is the rate at which charges flow past a point on a circuit. Current (I) is represented as, I = qt
The standard SI unit for current is ampere with the symbol A.
APPEARS IN
RELATED QUESTIONS
Fill in the folloing blank with suitable words:
Current is measured in ............... using an ............... placed in ............... in a circuit.
What happens to the other bulbs in a series circuit if one bulb blows off?
Give three reasons why different electrical appliances in a domestic circuit are connected in parallel.
Christmas tree lamps are usually wired in series. What happens if one lamps breaks?
Find the potential difference required to pass a current of 0.2 A in a wire of resistance 20Ω
Distinguish between an open and a closed circuit.
The following table shows the current in Amperes and potential differences in Volts.
- Find the average resistance.
- What will be the nature of the graph between the current and potential difference? (Do not draw a graph.)
- Which law will the graph prove? Explain the law.
V (volts) | I (amp) |
4 | 9 |
5 | 11.25 |
6 | 13.5 |
A bulb marked 12 V, 24 W operates on a 12 V battery for 20 minutes. Calculate:
- The current flowing through it, and
- The energy consumed.
The flow of electric charge per unit time is called potential difference.
What is the SI unit for the current?