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catkin
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Homework Statement
This is from Advanced Physics by Adams and Allday, section 8, practice exam questions, question 25.
An α-source with an activity of 150 kBq is placed in a metal can. A 100 V d.c. source and a 109 Ώ resistor are connected in series to the can and the source. This arrangement is sometimes called an ionisation chamber.
b) Describe how the nature of the electric current in the connecting wire differs from that in the air in the can.
d) With the α-source removed from the metal can, the voltmeter still registers a potential difference of 0.2 V Suggest two reasons why the current is not zero.
Homework Equations
None.
The Attempt at a Solution
b) Describe how the nature of the electric current in the connecting wire differs from that in the air in the can.
In the wire current is carried by electrons.
In the air current is carried by both electrons and positively charged ions.
I believe these answers are true but are they what the examiner was looking for?
d) With the α-source removed from the metal can, the voltmeter still registers a potential difference of 0.2 V Suggest two reasons why the current is not zero.
Background radiation creates some ionisation in the can.
Leakage?
I think "Background radiation" is a good answer but "Leakage" is weak. Is there something else the examiner might have been looking for?