• We need your support!

    We are currently struggling to cover the operational costs of Xtremepapers, as a result we might have to shut this website down. Please donate if we have helped you and help make a difference in other students' lives!
    Click here to Donate Now (View Announcement)

Physics: Post your doubts here!

Messages
237
Reaction score
41
Points
38
the current flows from the right vertical bar carrying three resistors in a row as switch is only connected to the left bar with two resistors ...track the path of the current ...when v = + ...and ull understand tht it will pass through the red LED..i didnt mean to say tht it is generated frm the ground .. i was talking abput the pathway
The current flows from Vout. The resistors now are not considered. Switch open> Vout positive > then the Red diode should be forward, in order to light up.
I am at least 95% sure
 
Messages
237
Reaction score
41
Points
38
send a snap of MS
might b deltaN/N = e*-λt
In the mark scheme, it says A = dN/dT
this is a rule which I agree on
then it says lambda = dN/N
shouldnt it be A=dN/dT and A=Lambda * N so
Lambda * N = dN/dT
so lambda =dN/ (N*dT)
???
they removed the dT in the markscheme idk why
 
Messages
537
Reaction score
358
Points
73
In the mark scheme, it says A = dN/dT
this is a rule which I agree on
then it says lambda = dN/N
shouldnt it be A=dN/dT and A=Lambda * N so
Lambda * N = dN/dT
so lambda =dN/ (N*dT)
???
they removed the dT in the markscheme idk why
which year?
 
Messages
237
Reaction score
41
Points
38
λ = decay constant
means - probability of decay of a nucleus per unit time
as activity =λN
deltaN/ delta t = λN
delta N/ N = λ / delta t
delta N= decayed nuclei N = total no. of nuclei
Last part doesn't make any sense.
And about the diode btw, am I wrong about the direction or what?
 
Messages
537
Reaction score
358
Points
73
Last part doesn't make any sense.
And about the diode btw, am I wrong about the direction or what?
if maximum possible error for decay is 10%
and the uncertainity in the calibration is 2%
then the element decays by 8 %
which means 92 % of element remains
as A/Ao = e*-λt
0.92 = e* (ln2 / 5.27 *365 ) t
231 days = t
 
Messages
237
Reaction score
41
Points
38
if maximum possible error for decay is 10%
and the uncertainity in the calibration is 2%
then the element decays by 8 %
which means 92 % of element remains
as A/Ao = e*-λt
0.92 = e* (ln2 / 5.27 *365 ) t
231 days = t
Oh my god LOL
why is 9) a) ii) delta N / N INSTEAD OF delta N / (N* delta T) which I got from lambda* N = delta N/ delta T so if you make lambda subject, you get that.
2) Am I correct about the orientations of the diodes, here : The current flows from Vout. The resistors now are not considered. Switch open> Vout positive > then the Red diode should be forward, in order to light up.
I am at least 95% sure
 
Messages
537
Reaction score
358
Points
73
Oh my god LOL
why is 9) a) ii) delta N / N INSTEAD OF delta N / (N* delta T) which I got from lambda* N = delta N/ delta T so if you make lambda subject, you get that.
2) Am I correct about the orientations of the diodes, here : The current flows from Vout. The resistors now are not considered. Switch open> Vout positive > then the Red diode should be forward, in order to light up.
I am at least 95% sure
omg the que asks us for the expression of the probability of decay not...λ,....λ= probability of decay per unit time
so the probability of decay would only b delta N/N
delta N = decayed nuclei
and N= total no. of nuclei
 
Messages
537
Reaction score
358
Points
73
Oh my god LOL
why is 9) a) ii) delta N / N INSTEAD OF delta N / (N* delta T) which I got from lambda* N = delta N/ delta T so if you make lambda subject, you get that.
2) Am I correct about the orientations of the diodes, here : The current flows from Vout. The resistors now are not considered. Switch open> Vout positive > then the Red diode should be forward, in order to light up.
I am at least 95% sure
i really dont get wat concept u hav regarding diodes cn u express it through some diag
 
Messages
237
Reaction score
41
Points
38
omg the que asks us for the expression of the probability of decay not...λ,....λ= probability of decay per unit time
so the probability of decay would only b delta N/N
delta N = decayed nuclei
and N= total no. of nuclei
Ahhhhhhhhhhhhhh!!!! That makes sense now! so probability of decay and decay constant are 2 different things :D
i really dont get wat concept u hav regarding diodes cn u express it through some diag
do you have the book? Page 399 it explains it
 
Messages
537
Reaction score
358
Points
73
Ahhhhhhhhhhhhhh!!!! That makes sense now! so probability of decay and decay constant are 2 different things :D

do you have the book? Page 399 it explains it
hello? there r mny which one...pacific?...internation as / a level cambridge?/
 
Top