Physics, Chemistry and Biology: Post your doubts here!

[EpicLol]

4 is resistance for first coil
6 is resistance for second coil

so the length of second coil is more....it is 1.5* bigger than the first coil
I think thats the answer but Im not sure....so do check with others

but why is like the diameter of the coil mentioned? I am confused....

 

[justforinformation]

4 is resistance for first coil
6 is resistance for second coil

so the length of second coil is more....it is 1.5* bigger than the first coil
I think thats the answer but Im not sure....so do check with others

Answer is 3/8 so wrong lol.

 

[EpicLol]

Answer is 3/8 so wrong lol.

yea I just checked but I dont understand why....so plz help ppl....that is a really tough question....

 

[Yousif Mukkhtar]

can anybody please tell me ,that in a transformer,v tend to decrease the resistance and current,to avoid power loses,but wont the decreasing of resistance ,increae the current??
plxxxxxxxxx

Don't confuse yourself in that thing. There is an equation for power loss and such stuff. There is no need to know the details.

 

[fatima360]

Don't confuse yourself in that thing. There is an equation for power loss and such stuff. There is no need to know the details.

thankss

 

[EpicLol]

Don't confuse yourself in that thing. There is an equation for power loss and such stuff. There is no need to know the details.

what is the equation for the power losses?

 

[Yousif Mukkhtar]

what is the equation for the power losses?

P=I2 x R

 

[Yousif Mukkhtar]

Guys, can anyone recommend me a good past paper question for Logic gates?

 

[Hamzeh S]

http://www.xtremepapers.com/papers/CIE/Cambridge IGCSE/Physics (0625)/0625_w11_qp_32.pdf
First question part B Why to use the energy at the positon in A while he clearly ask for speed at position where its vertical which means when its equal to 2 m the height why use the answer of A energy not mgh for the position he asked for then do 0.5mv2

 

[AAnsarii]

http://www.xtremepapers.com/papers/CIE/Cambridge IGCSE/Physics (0625)/0625_s10_qp_31.pdf question 11 b plOx xd.

Resistance is directly proportional 2 lenght, inversely prop,. 2 area. when u divide the diameter by 2, area increases by4. so new resistance=4(older resistance)*4= 16 ohms
now in d qn, they say dat I is 0.3, so actual resistance isn't 16, its 1.8/0.3=6 ohms
now d ratio... new resistance of actual lenght/calculated resistance of original length = 6/16 = 0.375.
, ma shaaAllahu la quwwata illa billah.

 

[xxxt]

i found that L2 is 3/8 of L1 since R=xL/A and they both have the same resistance and what changed was only the area which doubled because the diameter doubled.

 

[AAnsarii]

i found that L2 is 3/8 of L1 since R=xL/A and they both have the same resistance and what changed was only the area which doubled because the diameter doubled.

area wont double, it will b multiplied by 4!!!

 

[AAnsarii]

Guys, can anyone recommend me a good past paper question for Logic gates?

w11_32 i think

 

[Moi]

ALRIGHT THEN!
*bang head against desk*
TIME BASE
The time base effects the frequency of the shown wave!
If the time base is 1 second, then it will show the number of waves in 1 second!
If time base is 0.5 seconds it will show the number of waves in 0.5 seconds!
So the smaller the time base the less number of waves which appear/the wider they are. If you had LOTS of waves and they were all squashed, you would increase time base to make it clearer. This also means decreasing time base INCREASES wavelength of shown wave.
If it says time base is 5seconds/cm, it means that each cm represents 5 seconds. So if they ask to find the frequency from this this is what you do:
Find the number of centimeters/blocks for one wave (e.g. 5cm)
Multiply this by the time base (e.g if time base is 0.01second/cm, then that's 0.05cm)
This is the PERIOD the time taken for ONE wave
Frequency = 1/Period, so the frequency is 1/0.05 = 20Hz!
Y-GAIN
The Y-Gain effects the HEIGHT of the shown wave.
The height of the wave shows the voltage of the wave
So if the Y-Gain is 5volts/cm and the amplitude of the wave on the screen is 4cm, then the voltage of the wave is 5*4=20V!

Thanks it helped a bit

 

[EpicLol]

sby plz xplain 6(b)
http://www.xtremepapers.com/papers/CIE/Cambridge IGCSE/Physics (0625)/0625_w11_qp_31.pdf

I think its 0.58seconds for 200m in air 5128m/s

because its like speed in steel = speed in air - 0.544 and say thats x then do 1/x = y
then do y * 200 which would give you 5128m/s

 

[EpicLol]

Resistance is directly proportional 2 lenght, inversely prop,. 2 area. when u divide the diameter by 2, area increases by4. so new resistance=4(older resistance)*4= 16 ohms
now in d qn, they say dat I is 0.3, so actual resistance isn't 16, its 1.8/0.3=6 ohms
now d ratio... new resistance of actual lenght/calculated resistance of original length = 6/16 = 0.375.
, ma shaaAllahu la quwwata illa billah.

Plz help because I dont reeally understand that....could u explain it more simplified and elaborated so that idiots like me can understand thx

 

[MERIHAN]

http://www.xtremepapers.com/papers/CIE/Cambridge IGCSE/Physics (0625)/0625_s10_qp_32.pdf
Q NO 10 (A ) AND (B) IN THE ABOVE PASTPAPER ATTACHED LINK !!!! PLZ HELP ME ....THNX IN ADVANCE

 

[xxxt]

what is the difference between the accelerating anode and the focusing anode in the cathode ray ossiloscope????

 

[Stormcry72]

http://www.xtremepapers.com/papers/CIE/Cambridge IGCSE/Physics (0625)/0625_w11_qp_32.pdf
First question part B Why to use the energy at the positon in A while he clearly ask for speed at position where its vertical which means when its equal to 2 m the height why use the answer of A energy not mgh for the position he asked for then do 0.5mv2

because when vertical, we assume that height from ground level is zero and so gpe at that position is zero

 

[Mustafa omar]

http://www.xtremepapers.com/papers/CIE/Cambridge IGCSE/Physics (0625)/0625_s11_qp_31.pdf
Question 7 b i please I need to know how to solve it