IGCSE/GCSE/O & A Level/IB/University Student Forum

Qualification => Subject Doubts => GCE AS & A2 Level => Sciences => Topic started by: XaM!! on May 18, 2010, 11:16:08 am

Title: how to read a CRO
Post by: XaM!! on May 18, 2010, 11:16:08 am
plz guys i need help... how do v read a cero. theres always a ques in phy ppr 1... examples/ june 2004 ques 5
Title: Re: how to read a CRO
Post by: XaM!! on May 18, 2010, 11:19:40 am
I mean c.r.o... its a compulsory ques plz help...
Title: Re: how to read a CRO
Post by: halosh92 on May 18, 2010, 11:44:05 am
if u have a question from the pastpapers ill explain it to u.... all the questions are similar anyways ;D
Title: Re: how to read a CRO
Post by: XaM!! on May 18, 2010, 11:50:10 am
June 04 ques 5.
Title: Re: how to read a CRO
Post by: Friends on May 18, 2010, 12:06:48 pm
June 04 ques 5.

The ans is C because time base is double(increase), so more waves can fit in.
In first each box represent 10ms but now each box has to represent 20ms.
In first each wave took 4 boxes to complete but now it will take only 2 box to complete...
Hope this helps as i am not a gud explainer...
Title: Re: how to read a CRO
Post by: XaM!! on May 18, 2010, 12:31:27 pm
may june 03 ques 26
oct 04 ques 5... plz help because m stil confuse...
Title: Re: how to read a CRO
Post by: sabrina on May 18, 2010, 12:40:22 pm
hi i m not a good explaner but i will try to help u
whenever frency question comes use the formula 1/T. T stands for time period.
but how to find time period? i m coming to the point. use the formula time period=time base*no of boxes for 1 complete wave.
time period here is 2.5/1000(change to metre)*4=0.01
frequency=1/.01=100.
so the answer is B
hope u understood
Title: Re: how to read a CRO
Post by: halosh92 on May 18, 2010, 12:43:13 pm
may june 03 ques 26
oct 04 ques 5... plz help because m stil confuse...

ok c:
for one  cm square its 2.5ms
one complete wave takes 4 squares right
so:
1cm ------------------ 2.5 ms
4cm--------------------x
x=10 ms   (this is microsecond convert to seconds by dividing by 1000)
x=0.01 s
f=1/t   this is the equation relating frequnecy and time
f=1/0.01 =100 hertz
got it?
Title: Re: how to read a CRO
Post by: XaM!! on May 18, 2010, 01:02:09 pm
Thanks a lot guys... Thanks a ton...