# Interference from two radio antennae - simplistic and workings include

1. Apr 23, 2013

### elemis

Is this correct ?

I have an issue for the minima formula when n=1 I get theta = 90 degrees.

This doesn't make any sense.

Is my method correct ?

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2. Apr 23, 2013

### TSny

Your general method is correct, but your formula for the minima is incorrect. Check your notes or text.

3. Apr 23, 2013

### elemis

The formulas listed were in my notes.

Okay, for minima : 2λsinθ = mλ m=0.5,1.5,2.5,3.5...

This would give me the required non-integr half wavelengths for a minima, correct ?

EDIT : Hence m =0.5 would mean the first minima is at 30 degrees.

maxima : 2λsinθ = nλ n = 0,1,2,3,4,5....

For n =1 I still get theta to be 90 degrees.... I dont see what I'm doing wrong.

4. Apr 23, 2013

### rude man

5. Apr 23, 2013

### elemis

Can you check the post above yours, please ?

6. Apr 23, 2013

### rude man

No. 2sin(theta) = 0.5 does not yield theta = 30 deg.

No. 2sin(theta) = 1 does not yield theta = 90 deg.

7. Apr 23, 2013

### elemis

Ah, God, silly mistakes.... Forgive my lapse in concentration. Its pretty late where I am right now.

I've understood this question now. Thank you.