Essay
Unit 15C - Electrical Circuits and their Applications
- Institution
- PEARSON (PEARSON)
Unit 15C - Electrical Circuits and their Applications - distinction received Cheap and use when you need to hand in assignments quickly
[Show more]
2 reviews
By: nuhagi • 2 year ago
By: moizshehzad259 • 2 year ago
Content preview
Alternating current – when the current goes back and forth changing directionDirect current – when the current flows in one direction
When current passes through a tissue in the body it will heat up as a tissue has a resistance. Current passes
through resistance which causes heat energy to be produced.
, I=V/R
V – voltage source of electric shock
R – resistance of tissue
The amount of current passing through a human body depends on 2 things
Voltage supplied by the source and the electrical resistance of your body
Ear to ear -
110V
100 OHMS
= 1.1 mA
Hand to hand -
110 V
500 OHMS
+220mA
Dry skin -
(100,000 – 600,000 OHMS)
100V
100,000 OHMS
= 1.1mA
Wet skin -
110V
1000 OHMS
= 100mA
Dry skin -
I=V/R = 230/100,000 = 2.3mA
Causes a slight shock – not painful
Wet skin -
I=V/R - 230/1000 = 230mA
230mA leads to respiratory arrest which means you could possibly stop breathing
High voltage (500V or greater) breaks down the skin and reduces its resistance
2.3mA causes a slight shock – not painful
Current Effect
(contact for 1
s)
Below 1 mA Not perceptible
1 mA Threshold of feeling and tingling
5 mA Slight shock, not painful, average individual can let go. Involuntary
reaction can lead to indirect injuries
6-25 Painful shocks. Loss of muscle of control
mA(women)
9 to 30 mA Freezing current “can't let go” the person may be thrown away from the
2
BTEC Assignment Brief v1.0
BTEC Internal Assessment QDAM January 2015
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller Hamzamallu. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for £5.99. You're not tied to anything after your purchase.
Can Stuvia be trusted?
4.6 stars on Google & Trustpilot (+1000 reviews)
47561 documents were sold in the last 30 days
Founded in 2010, the go-to place to buy revision notes and other study material for 15 years now