Tutorial for electric charge, current, voltage, power, energy and circuit elements

 

1. What is the symbol for capacitance? Then state the capacitance unit.

2. “Watt” is the unit for which quantity?

3. What is electric charge?

4. What is the unit for resistance?

5. Fill in the blanks in Table 1 below.

Table 1: Electrical quantities

6. How many electrons in one coulomb?

7. Define electric current?

8. What is the different between direct current and alternating current?

9. If a conductor has a constant current of 2A, how many electrons pass a fixed point on the conductor in 30 seconds?

10. Define voltage and state the unit for voltage.

11. Define power and state the symbol for power.

12. Name two types of circuit elements.

13. Briefly explain about active elements and passive elements.

14. Give three example for passive elements.

15. Give two types of sources and briefly explain both of them.

16. Give one important reason of calculating energy in the electrical based system.

17. Tenaga Nasional Berhad (TNB) charges customers as shown in Table 2. This month, Mr. Samsul has to pay electricity bills as shown in Figure 1. Based on that information, calculate the total charge for Mr. Samsul.

Figure 1: Monthly electricity bills

Table 2: Tarif Rates from TNB

18. In a household, a 200W personal computer is run for 8hours/day, while 3 units of 60W bulbs run for 12 hours daily. A power company charges RM 0.30 per kWh of energy. Assuming the load usage is consistent throughout the day. Calculate the household electricity bill for a year.

19. Calculate how much energy is expended in moving a 20 coulomb charge through a potential difference of 0.5V.

20. State two differences between independent and dependent sources.

21. State four possible types of dependent sources and draw their symbol.

22. Sarina likes to take four slices of toasted bread as her breakfast every morning. The rated load for the toaster is 800W and it takes roughly 5 minutes to heat those four slices of bread. Find the cost of operating the toaster once per day for one month (30 days). Assume the cost per unit energy (kWh) is 27 cents.

23. The power dissapated by a resistor doubles if the applied voltage is doubles. (True/False)

24. An electricity company charges 30 cents for each kWh of energy delivered to domestic customers. If a house uses five 75W bulbs for four hours and a 1.5kW clothes drier for 30 minutes everyday, find the total cost of using the appliances for one week.

25. A circuit element has current, i(t) = 10e^-0.5t A and voltage, v(t) = 10 di/dt V. Calculate the power of the elements and the energy in 5 seconds.

26. A power company charges RM 0.30 per kWh of energy. What is the weekly cost of using six 100W bulbs for ten hours daily.