Differences between AC and DC
(sheet given)
Table explaining the differences/rules between series circuits and parallel circuits.
(sheet given)
Explica brevemente que las 3 magnitudes básicas, indicando como se simbolizan cada una y en que unidades se mide.
Complete the following sentences:
a. The force that is applied to a conductor to cause a current to flow is ______
b. With an increase of length or a decrease of cross-section of a conductor the resistance______
c. Current must always be expressed in______
d. The total current of a simple circuit with a voltage supply of 12 volts and a resistance of 24 ohms_ is______
e. When you have three bulbs connected in series, the same______will flow
through all of them.
f. When a lamp breaks and others continue working, they are connected in______
Name the following circuit symbols:
Draw the electric diagram of an electric circuit that consists of three
bulbs:
- connected in series. If one bulb is blown, what will happen?
- connected in parallel. If one bulb is blown, what will happen?
Workout the equivalent resistance
In the next exercises, batteries have equal values of 5 volts. Which circuit has the brighter globe, a or b? Why? What happens in c and d?
True or false?
- A voltimeter is connected in series to measure the voltage across a
component in a circuit.
- An ammeter is connected in series to measure the current flowing
through a component in a circuit.
- An ohmmeter is connected in parallel and with voltage to measure
the resistance of a resistor.
- The connection of a multimeter depends on what electrical
magnitude it measures.
Complete the sentences:
- To increase the current without modifying the voltage we
must______.
- To decrease the current without modifying the voltage we
must______.
- To increase the current without modifying the resistance we
must______.
- To decrease the current without modifying the resistance we
must______.
1. Resistance in a circuit is generally measured in units of ____.
A. W
B. Õ
C. K
D. Z
2. Which of the following is the correct expression of Ohm's Law?
A. I = R/V
B. R= P/V
C. I= P/V
D. I = V/R
13. If a 15-ohm resistor is connected in parallel with a 30 ohm-resistor, the equivalent resistance is?
A. 5
B. 7
C. 10
D. 15
What device is used to convert alternating current to direct current?
ı Q: Holding resistance constant, how does increasing current in a circuit
affect voltage?
ıQ: How would adding a 20-& resistor in parallel with a 100-& resistor
change the reading on an ammeter?
Q: When measuring DC voltage across a device with a multimeter, the
meter indicates 0 volts. What is one possible explanation for this reading?
Q: How should a multimeter’s leads be connected when measuring
resistance?
If a resistor suddenly decreases in value (resistance decreases), what will happen to the current through the resistor?
a. increases
b. remains unchanged
c. decreases
d. fluctuates
Which of the following is an appropriate use for a voltmeter?
a. To measure difference of potential
b. To measure current flow
c. To determine total resistance
d. To determine power output
2. Calculate the Req. Draw all the intermediate circuits.
3. In this circuit, calculate the Req, IT, V1, V2.
4. In the following circuit find: Req, IT, I1, I2, I3.
Put the following sentences in order.
a. Plugs are connected to an electric grid
b. An electric grid carries the electricity produced in Power Electric
stations.
c. Electricity is produced in Power Electric Stations.
d. Televisions must be plugged in to work
e. Televisions need electricity to work.
Fill the gaps with the words given:
Voltage, Current, Resistance
· ______is the number of electrons that pass through an electric
circuit every second.
· The opposition that some materials offer to the movement of
electrical current is called ______.
· ______is the energy given to electrons to pass through a
circuit.
Underline what you think is the most suitable word:
· The thicker and shorter a wire is the more/less resistance it has.
· The thinner and longer a wire is the more/less resistance it has.
What operation must you do in every case?
If I do not know……
· the current I must______(multiply / divide) ______
(voltage /current /resistance) by ______(voltage / current /
resistance)
· the voltage I must ______(multiply / divide) ______
(voltage /current /resistance) by ______(voltage / current /
resistance)
· the resistance I must ______(multiply / divide)
______(voltage /current /resistance) by ______
(voltage / current / resistance)