1. a) What happens to the LED if the resistor is replaced with a wire link.
   
   
   b) What is the approximate potential difference across the LED when normally lit.
   
   
   c) It it is safe to pass 10mA through the LED. Calculate a safe value for R. Assume the power supply voltage is 5 Volts.
   
   
   d) What value of R would you use if your exact calculated value is not available from suppliers.
   
   
   
   
   
   
2. If A₁ reads 3 amps and A₂ reads 1 amp, in amps, what does A₃ read?
   
   
   
   
   
   
   
3. If A₂ reads 2 amps and A₃ reads 3 amp, in amps, what does A₁ read?
   
   
   
   
   
   
   
4. If V reads 5 volts, what is the potential difference across R₁?
   
   
   
   
   
   
   
5. In what units is charge measured?
   
   
   
    
6. In what units is current measured?
   
   
   
    
7. In what units is potential difference measured?
   
   
   
    
8. When measuring potential, one lead from the volt meter is always connected to _______.
   
   
   
    
   
9. Giga means 10^x. What is the value of x?
   
   
   
    
10. Kilo means 10^x. What is the value of x?
    
    
    
     
11. Mega means 10^x. What is the value of x?
    
    
    
     
12. Milli means 10^x. What is the value of x?
    
    
    
     
13. Micro means 10^x. What is the value of x?
    
    
    
     
14. Nano means 10^x. What is the value of x?
    
    
    
     
15. Pico means 10^x. What is the value of x?
    
    
    
     
16. In what units is power measured?
    
    
    
     
17. In what units is resistance measured?