i know how to work it out but i dont know what it is ?
Root mean square value (rms) is the value of the current or voltage that gives the same heating affect ( power output) for a d.c circuit that an a.c does through the same resistor.
So for I rms
P =I^2 R .....direct current ... but for a.c we choose half the peak value ... as it is not at the maximum all of the time. ... for A.c P = 0.5 x I^2 x R
Making these two equal
I^ 2 rms x R = 0.5 x I^2 x R .... we can cancel the R's
Root mean square value (rms) is the value of the current or voltage that gives the same heating affect ( power output) for a d.c circuit that an a.c does through the same resistor.
So for I rms
P =I^2 R .....direct current ... but for a.c we choose half the peak value ... as it is not at the maximum all of the time. ... for A.c P = 0.5 x I^2 x R
Making these two equal
I^ 2 rms x R = 0.5 x I^2 x R .... we can cancel the R's
I think the 6 mark question will be either on finding an I-V characteristic or something to do with oscilloscopes. Maybe something on the photoelectric effect or line emission spectra. Unlikely to be on particles as this came up last year
What can they ask about line emission spectra and oscilloscopes that will be 6 marks?
What can they ask about line emission spectra and oscilloscopes that will be 6 marks?
June 12 had a 6 mark question regarding verifying the accuracy of a power source's rms using an oscilloscope. I've only seen a couple questions (excluding calculations) that involve oscilloscopes.
June 11's 6 marker was on how line spectra support the theory of atoms having discrete energy levels.
Potential dividers are retty much where you have two or more resistors in series ( If you read back quite a few pages in this thread you will see that I have explained the types of circuits associated with them.
But in all honesty you just need to be familiar with your VI graphs and the components such as LDR'S and themristors and the relationship they have with resistance and light or temperature respectively.
June 12 had a 6 mark question regarding verifying the accuracy of a power source's rms using an oscilloscope. I've only seen a couple questions (excluding calculations) that involve oscilloscopes.
June 11's 6 marker was on how line spectra support the theory of atoms having discrete energy levels.
June 12 had a 6 mark question regarding verifying the accuracy of a power source's rms using an oscilloscope. I've only seen a couple questions (excluding calculations) that involve oscilloscopes.
June 11's 6 marker was on how line spectra support the theory of atoms having discrete energy levels.
Can you link the mark schemes to these questions please so I can have a look please