Why Does a Toaster Use a Resistor to Transfer Energy?

[Masafi]

I have attached the question as a word file, along with the answers.

I didnt understand 2 parts:

1. The bit about which part of the circuit will transfer energy to surroundings. What is Ss, there is only S1 and S2. Also, why is that the answer?

2. When approximating a value for R
Time constant = 200 is taken. Why is this? Time constant is the time it takes for something to decay to 37% of its original value, or increase to 63% if it is an increasing curve.

Over here, 200s is the time taken for the TOTAL. Not the time constant??

 

[jbsteele]

To answer your first question, Ss is the switch in the circuit - it is the part of the circuit that will transfer energy to the surroundings. The reason it is the answer is because when the switch is closed, the current through the resistor will increase, thus transferring energy to the surroundings. As for your second question, the time constant of 200s is taken because it is the total time taken for the current to reach 63% of its maximum value. This can be calculated by taking the time taken for the current to go from 0 to 63% (which is 200s).

 

[kerimek]

1. The circuit in question is most likely a simple series circuit with a resistor (R), a switch (S1), and a timer (S2). In this case, S1 and S2 are the same switch, just labeled differently for clarity. The answer to which part of the circuit will transfer energy to the surroundings is R, the resistor. This is because the resistor is responsible for converting electrical energy into heat, which is then transferred to the surroundings. The switch (S1/S2) only controls the flow of electricity through the circuit, it does not actually transfer energy.

2. The time constant in this case is not referring to the decay or increase of a specific value, but rather the overall time it takes for the toaster to heat up and toast the bread. It is an approximation to give a general idea of how long it will take for the toaster to complete its task. The value of 200s is likely chosen based on the specific toaster being used and the desired level of toasting. This is not a precise value, but rather an estimation.