# Niamh Cullen tech y8 Electronics

 The flashcards below were created by user Anonymous on FreezingBlue Flashcards. Electronics - Circuits: What does it mean if two lights are "in series"? How does the current going through them compare to the current being supplied by the battery? It means that they are one after each other in a straight line. The current going through both is the same as the current being supplied by the battery. Electronics - Circuits: What does it mean if two lights are "in parallel" in a circuit? If there were three lights in parallel, how would the current going through each compare to the current being supplied by the battery? In parallel means that they appear in a parallel in a circuit. If three lights were in parallel, the current going though them would be 1/3rd of the current being supplied by the battery. Electronics - Circuits: Are the lights in series or in parallel? In series (current is the same throughout). Electronics - Circuits: Are the lights in series or in parallel? In parallel. Here, the current from the battery gets split into three. Each of the lights gets the same current through it, but this current is only 1/3rd of the current a bulb in a series circuit would get. Electronics - Switches: Draw the symbol for a "push to make" switch and describe what it does. It MAKES the circuit when pressed down. Electronics - Switches: Draw the symbol for a "push to break" switch and describe what it does. when pushed it BREAKS the circuit Electronics - Switches: Draw the symbol for a "reed" switch and describe what it does. when a magnet comes near, the reed wires are forced together to make the circuit. Electronics - Switches: Draw the symbol for a "On/off" switch and give another name for it. another name is : SPST switch(single pole, single throw) Electronics - Switches: Draw the symbol for a "2 way" switch and give another name for it. another name is SPDT switch.(single pole, double throw) Electronics - LEDs: What does LED stand for? Light Emitting Diode Electronics - LEDs: When including an LED in any circuit, what must you remember to include, and why? To put a resistor in front of it in the circuit. This is because LEDs only need a tiny amount of current (max 30mA) and the resistor will dramatically reduce the current going into the LED so it doesn't burn out. LEDs typically operate between 10-20mA of current. Electronics - LEDs: What are the two legs of an LED called and which one is postive / negative? Anode - negative (think of anti)Cathode - positive (this leg is longer than the anode) Electronics - LEDs: What is the safe operating voltage of an LED? 1.5 volts up to 5 volts Electronics - LEDs: What way should a LED be connected to a battery (postive / negative)? The negative ANODE should be connected to the POSTIVE BATTERY terminal. The positive CATHODE should be connected to the NEGATIVE BATTERY terminal. Electronic - Circuit Calculations: What is the formula relating voltage, current and resistance? What are the units of each? V = I . RV is voltage and is in VOLTSI is current and is in AMPSR is resistance and is in OHMS Electronic - Circuit Calculation: If a circuit has a 9V battery and the resistor is 200ohms, will the LED work ok (show why)? No the LED will burn out, because the current going though it will be too high. Using V = I.RI (current) would be 9/200 = 0.045A = 45mA. Most LEDs will burn out at above 30mA. AuthorAnonymous ID58765 Card SetNiamh Cullen tech y8 Electronics Descriptionniamh y8 tech electronics Updated2011-01-09T14:44:00Z Show Answers