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level: Circuit components

Questions and Answers List

level questions: Circuit components

QuestionAnswer
A resistor with a constant resistance value that does not change with variations in current or potential difference.Fixed Resistor
How does the resistance of a fixed resistor behave with changes in current?The resistance of a fixed resistor remains constant and does not change with variations in current.
A relationship between two quantities, where one quantity is directly proportional to the other, meaning they increase or decrease together by a constant factor.Direct Proportionality
How is current related to potential difference in a fixed resistor?The current through a fixed resistor is directly proportional to the potential difference across it.
The impact of temperature on the resistance of a component; for fixed resistors, resistance remains constant if the temperature is constant.Temperature and Resistance
What condition is crucial for the direct proportionality of current and potential difference in a fixed resistor?The temperature must remain constant for the current to be directly proportional to the potential difference in a fixed resistor.
Components whose resistance changes with variations in current or potential difference.Variable Resistance Components
Give examples of components whose resistance changes with current.Filament lamps and diodes are examples of components whose resistance changes with current.
A type of light bulb that contains a wire filament, and its resistance increases as it heats up when current flows through it.Filament Lamp
How does the resistance of a filament lamp change with an increase in potential difference?The resistance of a filament lamp increases with an increase in potential difference, as the temperature of the filament rises.
The store of energy associated with the random motion of particles in a substance.Thermal Energy Store
What happens to the energy when a current flows through a filament lamp?Some of the energy is transferred into the thermal energy store of the filament, causing it to heat up.
A semiconductor device that allows current to flow in one direction only, having a very high resistance in the reverse direction.Diode
Why does a diode have a very high resistance in the reverse direction?A diode's resistance is high in the reverse direction to prevent current flow in that direction.
A resistor that changes its resistance with variations in temperature, increasing at low temperatures and decreasing at high temperatures.Thermistor
How can thermistors be used in circuits?Thermistors can be used in circuits as temperature sensors or thermostats due to their resistance changes with temperature.
A resistor whose resistance depends on the intensity of light, having high resistance in low light and low resistance in bright light.Light Dependent Resistor (LDR)
What is the resistance of an LDR in low levels of light?In low levels of light (low light intensity), the resistance of an LDR is high.
The amount or brightness of light in a particular area.Light Intensity
How can LDRs be used in circuits?LDRs can be used in circuits that automatically control lights based on the surrounding light intensity.
A device that maintains a set temperature in a system by controlling the heating or cooling mechanisms.Thermostat
How can thermistors be utilized in thermostat applications?Thermistors can be used as temperature sensors in thermostats to regulate heating or cooling systems based on temperature changes.
A circuit used to test how resistance varies in different devices.Resistance Testing Circuit
What components are essential in a resistance testing circuit?An ammeter (in series to measure current) and a voltmeter (in parallel to measure potential difference) are essential components.
A device used to measure electric current in a circuit, typically connected in series.Ammeter
How is an ammeter connected in the circuit for resistance testing?An ammeter is connected in series with the device being tested to measure the current.
A device used to measure the potential difference (voltage) across a component in a circuit, typically connected in parallel.Voltmeter
How is a voltmeter connected in the circuit for resistance testing?A voltmeter is connected in parallel with the device being tested to measure the potential difference.
A resistor with an adjustable resistance, used to change the current in the circuit.Variable Resistor
When testing a filament light bulb or diode, what is the purpose of the variable resistor?The variable resistor is used to change the current in the circuit, especially when testing filament light bulbs or diodes.
A visual representation of the relationship between two variables, such as current and potential difference, resistance and temperature, or resistance and light intensity.Graph
Why would you draw a graph of current against potential difference in some resistance tests?Drawing a graph of current against potential difference helps visualize and analyze the behavior of components like filament light bulbs or diodes.
A resistor that changes its resistance with variations in temperature, commonly used as a temperature sensor.Thermistor
What type of graph would you draw when testing a thermistor?A graph of resistance against temperature is drawn when testing a thermistor.
A resistor whose resistance depends on the intensity of light.Light Dependent Resistor (LDR)
What type of graph would you draw when testing an LDR?A graph of resistance against light intensity is drawn when testing an LDR.