click below
click below
Normal Size Small Size show me how
Current Electricity
Junior Cert Science
| Question | Answer |
|---|---|
| What causes an electric current | A flow of electrons |
| What is a conductor | A material that allows a current to flow |
| What is an insulator | A material that does not allow a current to flow |
| Give an example of a conductor | Metal |
| Give an example of an insulator | Wood or plastic |
| Where are electrons produced | At the negative terminal |
| In what direction do electrons flow in a circuit | From the positive to the negative terminal |
| What do you call the difference in pressure between the positive and the negative terminals | Potential difference |
| What is the other name for potential difference | Voltage |
| What is voltage measured in | Volts |
| What is the symbol for volts | V |
| How would you measure voltage | Voltmeter |
| What do you call the ability a substance has to resist the flow of electrons | Resistance |
| What is resistance measured in | Ohms |
| Give an example of a resistor in a circuit | light bulb filament |
| What is the term used to describe the flow of electricity | Current |
| What is current measured in | Amps (I) |
| What would you use to measure the flow electrical charge | Ammeter |
| What Law states that at constant temperature, the voltage (V) is always proportional to the current in a circuit | Ohms Law |
| What type of resistor can be used to control the voltage in a current | Variable resistor |
| How would you describe the relationship between voltage and current | Proportional - if voltage is increased then current will also increase |
| What would you call a circuit where bulbs are connected one after the other | Series circuit |
| In a series circuit, what happens the bulbs as the current passes through | They get dimmer |
| What would you call a circuit where bulbs are connected side by side | Parallel circuit |
| If a bulb is disconnected in a circuit but the others continue to light , what type of circuit would this be | Parallel circuit |
| Name three effects of an electric current | Heating, Magnetic and Chemical |
| Give an example of the heating effect of a current | Element in a kettle |
| Give an example of the magnetic effect of a current | Electromagnet |
| Give an example of the chemical effect of a current | Electrolysis -splitting of water |