Edexcel - London Examinations GCE, January 1999 - Paper 2 Question 5

5.

a)

.

   

 

b)

i) See diagram

    ii) See diagram

    iii) A slit can be placed between the prism and the screen so that a particular colour of light is chosen and allowed to fall on the LDR.

     Method:

    The LDR is placed in one position from A to B with the slit in such a position as to allow only one colour to fall on the LDR. The reading on the milliammeter is taken. The process is repeated by allowing various colours to fall on the LDR, one at a time and each time measuring the current on the meter.

     

    iv) Table of results:

 

Colour of light falling on LDR Current on milliammeter for that colour LDR current in total darkness
Red    
Orange    
Yellow    
Blue    
Indigo    
violet    

 

 

To calculate the response the values in the second column and the third column are noted down.

 

(14 marks)