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Blazing goIITian

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10 May 2007 19:26:46 IST

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611

a give away ques

None

threshold wavelength for a metal is 5250 Anstrom
for emission of photo electrons the wave length should be
1.>5250A
2.<5250A
3.=5250A

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Aditya Arora

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10 May 2007 19:30:31 IST

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Answer is 3 i.e =5250A.

This is because when light of wavelength equal to threshold wavelength of the metal, electrons are emitted with KE =0.

For >5250A , electrons will be emitted, but with KE>0.

ravi dvr

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10 May 2007 19:30:35 IST

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2.<5250 A

lol...

VIKAS REDDY

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10 May 2007 19:31:31 IST

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i think its <5250

TARUN BHATIA

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10 May 2007 19:32:07 IST

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ANSWER IS 2 THE WAVELENGTH SHOULD BE LESS THAN THE THRESHOLD WAVELENGTH

I KNOW IT WAS AN EASY Q
BUT STILL PLEASE RATE ME IF I AM CORRECT.

MUDIT

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21 May 2007 23:30:18 IST

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I THINK THE FIRST OPTION IS CORRECT BECAUSE AT THE THRESHOLD WAVELENTH THE PHOTOELECTRONS EMMITED WILL BE NEGLIGIBLE.THWE PROBABILITY OF FINDING A PHOTO ELECTRON IS ALMOST 0. THE INTENSITY OF THE EMMITED PHOTONS WILL RISE AS THE WAVELENTH INCREASES FROM THE THRESHOLD ENERGY, REACH A PEAK VALUE AND THEN DECLINE.

Pranjal Malagi

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21 May 2007 23:41:20 IST

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Please tell the correct answer n reason if u know

balaji nandhu

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22 May 2007 23:17:16 IST

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for emission of photo electron either
1.freq. should be >threh freq or
2.wlength should be<thresh wlength
(as freq is inversely related to wlength)

edison

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Joined: 19 Oct 2006

Posts: 7537

31 May 2007 14:32:48 IST

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The concept and relation for threshold wavelength is just reciprocal of threshold frequency so answer is

2.<5250A

But for calculation purpose it is taken as = 5250 A

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