Biology; Chemistry; Physics: Post your doubts here!

[Hskk]

this statement is correct, but you don't consider only this factor. The fact is when there is higher resistance, the overall current flow would become less. This would lead to less voltage, and therefore less energy would be dissipated per charge while going through the bulb. As a result, overall less heat would be produced. (just read some of it from google to be sure )

You see, voltage remains the same since the source(battery, mains etc) provides a definite amount that remains constant. So, if larger resistance equals more brightness, N03/Q25/P1 should be D.

 

[asma tareen]

wait i thought lagr resistance results in less brightnesss i mean thats what the experiment showed so isnt it correct

 

[TheStallion-Reborn]

It passes from the top to the circuit and then back from the bottom (I guess ).

direction of the current=direction of deflection i guess

 

[Hskk]

wait i thought lagr resistance results in less brightnesss i mean thats what the experiment showed so isnt it correct

Which experiment?

 

[asma tareen]

the one we did at school

Which experiment?

 

[usama321]

You see, voltage remains the same since the source(battery, mains etc) provides a definite amount that remains constant. So, if larger resistance equals more brightness, N03/Q25/P1 should be D.

we are talking about the p.d across the lamp. This p.d is what matters to us, because the higher it is, the more difficult it is for the electrons to pass through that lamp, resulting in higher light. But, you see, when there is high resistance, even though the pd should have become high too, it does not cuz the overall current decreases in the circuit, resulting in lower flow of electrons and lower pd. But, if we reduce the resistance, even though the p.d across that point would be lesser than before, the increased current would cause the increased pd, as more electrons are trying to flow from the same narrow lane. As a result, it grows brighter

 

[HDIWAN]

wher

wait i thought lagr resistance results in less brightnesss i mean thats what the experiment showed so isnt it correct

where there is larger resistance there is larger voltage and so more brughter bulb tht would be...since the supply IS FROM MAINS so voltage will remain same no matter what .So now we look where the current will be highest. since current is inversely proportional to the resistance it will highest where resistance is lower so brightness will be more in the bulb with high current ( this is the case only for same voltage in two bulbs)

 

[usama321]

wher
where there is larger resistance there is larger voltage and so more brughter bulb tht would be...since the supply IS FROM MAINS so voltage will remain same no matter what .So now we look where the current will be highest. since current is inversely proportional to the resistance it will highest where resistance is lower so brightness will be more in the bulb with high current ( this is the case only for same voltage in two bulbs)

you are confusing the voltage of the supply with the potential difference across a specific point, the voltage is not the same in the whole series circuit.

 

[usama321]

wher
where there is larger resistance there is larger voltage and so more brughter bulb tht would be...since the supply IS FROM MAINS so voltage will remain same no matter what .So now we look where the current will be highest. since current is inversely proportional to the resistance it will highest where resistance is lower so brightness will be more in the bulb with high current ( this is the case only for same voltage in two bulbs)

Which experiment?

got it or should i explain more?

 

[HDIWAN]

you are confusing the voltage of the supply with the potential difference across a specific point, the voltage is not the same in the whole series circuit.

are we not talking abt tht mcq the one from main supply?.. because in main supply like in our homes the lightening circuts are in parallel arrangement

 

[asma tareen]

got it or should i explain more?

i need an explanation

 

[AhsanS]

Hey,
Help for Biology : Need help for the topic Nitrogen cycle and Teeth, notes wuld also be helpful
thanks

 

[usama321]

are we not talking abt tht mcq the one from main supply?.. because in main supply like in our homes the lightening circuts are in parallel arrangement

firstly nope. If it had been parallel, your answer is right

i need an explanation

K now lets start from beginning. A lamp is supposed to be more bright when its resistance is high, this being because as the resistance of the lamp is high, the potential difference across it would be higher. this would mean that more energy would be required per charge when going through the lamp, and as a result more heat and thus light energy will be produced, resulting in a brighter lamp. NOW THIS IS WRONG

Why? because due to the high resistance of the bulb, the overall current in the circuit would decrease. As a result, the p.d across the lamp would decrease too. What really happens is that the lamp glows brighter when its resistance is low. You might question this as higher resistance means more heat, and i am saying the exact opposite.

Well this is because due to the low resistance, the overall current in the circuit increases. Now you might think that the p.d across the lamp might be lower too due to the lower resistance but this is not so. Because of the higher current, more electrons would be trying to go through the same narrow path of the wire through the lamp. This would result in a high p.d across the lamp, and overall a brighter lamp

Hskk asma tareen

 

[HDIWAN]

i need an explanation

according to my info. pd(voltage) accross any bulb is more if its resistance is more becasue voltage is basically the push on the electric current so greater push(voltage) is require where there is more resistance so when there is more voltage accross a bulb its brightness also INCREASES. thus we concluded more resistance results in more brightness due to high voltage.
in parallel circuit since voltage remains the same we conclude which bulb will be brighter by looking where current will be more.so current is highest where resistance is lowest so that bulb will be brighter. Now the question say from mains it makes it clear tht voltage/pd will be same for both bulbs but bulb with less resistance will have more current so will be brighter thus X is bulb with less resistanc. (correct me if i am wrong)

 

[Hskk]

we are talking about the p.d across the lamp. This p.d is what matters to us, because the higher it is, the more difficult it is for the electrons to pass through that lamp, resulting in higher light. But, you see, when there is high resistance, even though the pd should have become high too, it does not cuz the overall current decreases in the circuit, resulting in lower flow of electrons and lower pd. But, if we reduce the resistance, even though the p.d across that point would be lesser than before, the increased current would cause the increased pd, as more electrons are trying to flow from the same narrow lane. As a result, it grows brighter

I. Get. It. *JumpsAroundClappingMerrily*

 

[asma tareen]

firstly nope. If it had been parallel, your answer is right


K now lets start from beginning. A lamp is supposed to be more bright when its resistance is high, this being because as the resistance of the lamp is high, the potential difference across it would be higher. this would mean that more energy would be required per charge when going through the lamp, and as a result more heat and thus light energy will be produced, resulting in a brighter lamp. NOW THIS IS WRONG

Why? because due to the high resistance of the bulb, the overall current in the circuit would decrease. As a result, the p.d across the lamp would decrease too. What really happens is that the lamp glows brighter when its resistance is low. You might question this as higher resistance means more heat, and i am saying the exact opposite.

Well this is because due to the low resistance, the overall current in the circuit increases. Now you might think that the p.d across the lamp might be lower too due to the lower resistance but this is not so. Because of the higher current, more electrons would be trying to go through the same narrow path of the wire through the lamp. This would result in a high p.d across the lamp, and overall a brighter lamp

Hskk asma tareen

hmm kay i got it thnx

 

[HDIWAN]

firstly nope. If it had been parallel, your answer is right


K now lets start from beginning. A lamp is supposed to be more bright when its resistance is high, this being because as the resistance of the lamp is high, the potential difference across it would be higher. this would mean that more energy would be required per charge when going through the lamp, and as a result more heat and thus light energy will be produced, resulting in a brighter lamp. NOW THIS IS WRONG

Why? because due to the high resistance of the bulb, the overall current in the circuit would decrease. As a result, the p.d across the lamp would decrease too. What really happens is that the lamp glows brighter when its resistance is low. You might question this as higher resistance means more heat, and i am saying the exact opposite.

Well this is because due to the low resistance, the overall current in the circuit increases. Now you might think that the p.d across the lamp might be lower too due to the lower resistance but this is not so. Because of the higher current, more electrons would be trying to go through the same narrow path of the wire through the lamp. This would result in a high p.d across the lamp, and overall a brighter lamp

Hskk asma tareen

so its abt pd....ohk got it thanks

 

[AhsanS]

i dont like to repost..but..agian
can some one guide me to notes for Teeth and Nitrogen cycle for Bio

 

[usama321]

i dont like to repost..but..agian
can some one guide me to notes for Teeth and Nitrogen cycle for Bio

sorry am studying computer

 

[Dan_T]

I'd really appreciate some help in Bio regarding teeth ( mainly cross section and internal structure) and the nitrogen cycle...Ive always been confused cuz theres so many different bacteria involved....and how nitrates are being formed but CO2 is still being produced. Any help or even any notes would be rly appreciated guys!! Exams pretty closeee... Thanks.