The answer is D, cuz if you equate mw^2r to Bqv, according to the question, q=e and m=m obv, Using v=wr we can cancel v on both sides. So, mw=Be then using w=2pi/t we get 2pim/T = Be rearrange that to make T the subject and there you go!
The answer is D, cuz if you equate mw^2r to Bqv, according to the question, q=e and m=m obv, Using v=wr we can cancel v on both sides. So, mw=Be then using w=2pi/t we get 2pim/T = Be rearrange that to make T the subject and there you go!
that's what i did and i got D but my mark scheme says the answer is B...
that's what i did and i got D but my mark scheme says the answer is B...
I've got that question in a booklet made by my college, and the answer in their mark scheme is D. I agree with handsome7654's working, so it must just be a mistake in the mark scheme.
I've got that question in a booklet made by my college, and the answer in their mark scheme is D. I agree with handsome7654's working, so it must just be a mistake in the mark scheme.
The diagram shows two charges, +4 μC and –16 μC, 120 mm apart. What is the distance from the +4 μC charge to the point between the two charges, where the resultant electric potential is zero? A) 24mm B) 40mm C) 80mm D) 96mm
The diagram shows two charges, +4 μC and –16 μC, 120 mm apart. What is the distance from the +4 μC charge to the point between the two charges, where the resultant electric potential is zero? A) 24mm B) 40mm C) 80mm D) 96mm
Thanks
you use the electric potential formula
V=Q/4piepsilon0 x r but the 4piepsilon0 cancels for both so jus ignore it
so for the 4uC you do V=4uC/120 and for the -16uC you do V=-16uC/120-x
Thanks. When i equate them, I get 480u-4ux= -1920u -4ux=-2400u x=600
where am i messing up?
Do it like this; Cuz the sum of the potentials at a distance x away from 4uC is 0, you get +4u/4piepsilon0(x) - 6u/4piepsilon0(20-x) = 0, then add 6u/4piepsilon0(12-x) to both sides, 4u/x = 6u/120-x (the 4piepsilon0 bit cancels), then multiply by (120-x) 480u - 4ux = 16ux so x = 480u/20u = 24mm!
I have just spent all day printing off every multi choice question from the past 10 years. Highligting the right answer and cutting them out. Then placing them in 7 piles (pile for each topic). After removing recent questions and questions that have already been repeated once I think I can guess a few of out questions, well the ones they will be re-using anyway.
I have just spent all day printing off every multi choice question from the past 10 years. Highligting the right answer and cutting them out. Then placing them in 7 piles (pile for each topic). After removing recent questions and questions that have already been repeated once I think I can guess a few of out questions, well the ones they will be re-using anyway.
I have just spent all day printing off every multi choice question from the past 10 years. Highligting the right answer and cutting them out. Then placing them in 7 piles (pile for each topic). After removing recent questions and questions that have already been repeated once I think I can guess a few of out questions, well the ones they will be re-using anyway.
Can I ask how you got access to all those past papers? If there is a website for them, can u give me the link plzz?? Really need some practice cuz iv only been getting C/Ds on my practice papers!!