Edexcel IAL Physics Unit 2 - 17th May 2019Watch

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#1
Well, just another thread to discuss unit 2 stuff.
Drop in any resources or material that might help others to pass this exams.
Drop in questions for each other tooo.
I wish you all the best!!!!!!
1
5 days ago
#2
I'm finding problems in Electricity MCQs! Pretty awful they are!😖
0
5 days ago
#3

Isn't this Doppler Effect?
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5 days ago
#4
(Original post by dsn_o_u_r_e_e_n)

Isn't this Doppler Effect?
Yes it is not in the syllabus anymore.
0
5 days ago
#5
Yaayy!
(Original post by ameer10)
Yes it is not in the syllabus anymore.
0
5 days ago
#6

How is power and current related to efficiency with its increase or decrease? And what will be the answer?
Last edited by username4667968; 5 days ago
0
5 days ago
#7
(Original post by dsn_o_u_r_e_e_n)

How is power and current related to efficiency with its increase or decrease?
0
5 days ago
#8
I thought the same too but the answer is D
(Original post by ameer10)
0
5 days ago
#9
(Original post by dsn_o_u_r_e_e_n)

How is power and current related to efficiency with its increase or decrease? And what will be the answer?
Wait i think it is D because they have the same brightness so the same useful output. The total input of the LED is the lowest so it had more efficiency because total output is in the denominator so when they decreases the efficiency increases
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5 days ago
#10
(Original post by dsn_o_u_r_e_e_n)
I thought the same too but the answer is D
Yeah my bad, I wasn't focusing enough when I replied with A 😅
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5 days ago
#11
Its okay!
(Original post by ameer10)
Yeah my bad, I wasn't focusing enough when I replied with A 😅
0
5 days ago
#12
Mm can you make it easier to understand?
(Original post by ameer10)
Wait i think it is D because they have the same brightness so the same useful output. The total input of the LED is the lowest so it had more efficiency because total output is in the denominator so when they decreases the efficiency increases
0
5 days ago
#13
(Original post by dsn_o_u_r_e_e_n)
Mm can you make it easier to understand?
efficiency = useful power output / total power input.
because they have the same brightness, they have the same useful energy output.
LED has lowest power input hence it has the most efficiency.
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5 days ago
#14
Wow thank you
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5 days ago
#15

2 no.?
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5 days ago
#16
(Original post by dsn_o_u_r_e_e_n)

2 no.?
is it B?
it should be B
Last edited by ameer10; 5 days ago
0
5 days ago
#17
(Original post by ameer10)
is it B?
it should be B
Yes but why?
0
5 days ago
#18
(Original post by dsn_o_u_r_e_e_n)
Yes but why?
Resistance is proportional to length and inversely proportional to area. So, when the length doubles the resistance will double so now its 12 BUT the area also doubles so the resistance should halve so now its back to 6 again.
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5 days ago
#19
Wowok your prep is so good😭
(Original post by ameer10)
Resistance is proportional to length and inversely proportional to area. So, when the length doubles the resistance will double so now its 12 BUT the area also doubles so the resistance should halve so now its back to 6 again.
0
5 days ago
#20
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