The DAV Class 6 Science Book Solutions and DAV Class 6 Science Chapter 11 Question Answer – Electric Currents and Circuits are essential study tools for DAV public school students in Class 6.
DAV Class 6 Science Ch 11 Question Answer – Electric Currents and Circuits
DAV Class 6 Science Ch 11 Solutions – Electric Currents and Circuits
Something To Know
A. Fill in the blanks.
Question 1.
The thin coiled wire, that gives light, when heated up, is known as the ______ of an electric bulb.
Answer:
Filament
Question 2.
An electrical device needs at least ______ terminals.
Answer:
Two
Question 3.
An electric bulb glows when ______ flows through it.
Answer:
Electric current
Question 4.
The device, that is used to ‘break’ or ‘make’ an electric circuit, is called a ______
Answer:
Switch/key
Question 5.
The materials, which (easily) let electricity flow through them, are called ______
Answer:
Conductors
Question 6.
Electric current ______ pass through a sheet of thermocole.
Answer:
Cannot
B. Write True or False for the following statements.
1. A dry cell stops working when the chemical in it get used up.
2. Electric current is taken to flow from the negative terminal of the (electric) cell to the positive terminal of the cell.
3. We need to complete the relevant electric circuit to enable an electric device to work.
4. Button cells are used in wrist watches.
5. We can use a polyester thread, in place of metal wires, to complete an electric circuit.
Answer:
1. A dry cell stops working when the chemical in it get used up. (True)
2. Electric current is taken to flow from the negative terminal of the (electric) cell to the positive terminal of the cell. (False)
3. We need to complete the relevant electric circuit to enable an electric device to work. (True)
4. Button cells are used in wrist watches. (True)
5. We can use a polyester thread, in place of metal wires, to complete an electric circuit. (False)
C. Tick (✓) the correct option.
1. The thin metal wire inside an electric bulb, is known as
(a) Insulation
(b) Terminal
(c) Filament
(d) Fiber
Answer:
(c) Filament
2. When an electric current starts flowing in an electric bulb, it starts emitting light because its
(a) Filament starts emitting light and then gets heated up.
(b) Thick connecting wires start emitting light and then get heated up.
(c) Filament gets heated up and then starts emitting light.
(d) Thick wires get heated up and then start emitting light.
Answer:
(c) Filament gets heated up and then starts emitting light.
3. The basic electric circuit needs to have
(a) Only a source of electric current.
(b) Only a few conducting wires.
(c) Only an electric switch.
(d) A source of electric current, a few conducting wires as well as an electric switch.
Answer:
(d) A source of electric current, a few conducting wires as well as an electric switch.
4. The electric bulb, in the circuit shown here, would glow when
(а) Both switches 1 and 2 are in their ‘OFF’ positions.
(б) Switch 1 is in its ‘OFF’ position but switch 2 is in its ‘ON’ position.
(c) Switch 1 is in its ‘ON’ position but switch 2 is in its ‘OFF’ position.
(d) Both switches 1 and 2 are in their ‘ON’ positions.
Answer:
(d) Both switches 1 and 2 are in their ‘ON’ positions.
5. The relevant examples ( 2 each) have been correctly tabulated only in table
(a)
| Conductors | Insulators |
| Silver | Bakelite |
| Copper | Plastic |
(b)
| Conductors | Insulators |
| Gold | Bakelite |
| Silver | Plastic |
(c)
| Conductors | Insulators |
| Bakelite | Silver |
| Copper | Plastic |
(d)
| (d) Conductors | Insulators |
| Gold | Bakelite |
| Plastic | Copper |
Answer:
(b)
| Conductors | Insulators |
| Gold | Bakelite |
| Silver | Plastic |
D. Answer the following questions in brief.
Question 1.
State the function of the metallic strips used in a torch.
Answer:
The metallic strip in torch works as conducting wire and supplies electric current from the cell to the bulb.
Question 2.
The given diagram shows a dry cell with its different parts marked as 1, 2, 3, 4 and 5. Which of them are the ‘two terminals’ of the dry cell?
Answer:
1 and 5
Question 3.
Write the meaning of the term ‘electric circuit’.
Answer:
A path through which electric current flows is called electric circuit.
Question 4.
State the role of an electric switch in an electric circuit.
Answer:
An electric switch is used for opening or closing the circuit as and when required.
Question 5.
Tools, like screw drivers and pliers, used by electricians, have handles made up of (or covered with) plastic, rubber or wood. Why?
Answer:
Plastic, rubber or wood are bad conductors of electricity. Handles of an electrician’s tools are made up of these materials. This helps in preventing electric shock to the electrician when he is repairing any fault in electric supply.
Question 6.
Why should we always dry our hands before touching an electric appliance or a switch?
Answer:
Normal water is good conductor of electricity. Due to this, touching an electric appliance or
switch with wet hands can result in electric shock. So, to prevent electric shock, we should always dry our hands before touching an electric appliance or switch.
E. Answer the following questions.
Question 1.
Write in brief, the working of an electric torch.
Answer:
An electric torch is made up of a cell or a battery, a conducting metallic strip and a bulb; which are encased in a container. When the switch is pressed or slid, the circuit becomes complete and the bulb glows. This happens because the electric current is being supplied from the cell to the bulb.
Question 2.
A student, while performing an experiment in the science laboratory, connected an electric bulb to an electric cell through an electric switch. He noticed that the bulb did not glow when the electric switch was set in its ON position. Mention ‘any two reasons’ for this observation.
Answer:
Electric wires may not be tightly fit. The electric cell may be exhausted.
Question 3.
Separate out the devices listed below, into categories that usually work with (i) either batteries or mains (ii) batteries only (iii) mains only. Kettle, iron press, calculator, toaster, mobile phone, washing machine, radio, transistor, computer, microwave oven.
Answer:
Either batteries or mains: Radio, transistor Batteries only: Calculator, mobile phone Mains only: Kettle, iron press, toaster, washing machine, computer, microwave oven
Question 4.
Match the labels to the correct parts of the circuit given below.
Provides electricity A device making/breaking a circuit Device which lights up
Answer:
Yes, this circuit will work because it has all the required parts.
Question 5.
Distinguish between the terms conductors and insulators of electricity. Give two examples of each type.
Answer:
| Conductors | Insulators |
| They allow electric current to pass through them. | They don’t allow electric current to pass through them. |
| Examples: copper, aluminium. | Examples: wood, rubber. |
Value Based Questions
The science teacher, on entering the class, observed that Ritika was looking quite upset. When she asked her the reason, Ritika told her that she had forgotten her raincoat in the bus. The teacher consoled her and advised her to be careful and particular about her belongings. She also told her not to get too upset and stay positive in her thoughts. She told her that positive thoughts light up our life in much the same way as an electric current lights up the bulb through which it flows.
Question 1.
Identify the values conveyed by the teacher to Ritika.
Answer:
Positive attitude, forget the past.
Question 2.
How does an electric bulb light up’ when an electric current flows through it.
Answer:
When electric current flows through a bulb then its filament heats up and begins to glow. Thus, an electric bulb produces light.
Question 3.
Have a group discussion in which one student states some situation/incident. Let the other students give their suggestions about dealing with that situation/incident.
Answer:
Do it yourself.
Something To Do
Question 1.
Electric switches come in different sizes and shapes. Look around and list the different electrical devices/appliances in terms of their switches in a tabular form.
Answer:
| Appliances/devices without switches | With one switch | More than one switch |
| Mobile phone, wrist watch | Table lamp, table fan | Mixer grinder, microwave oven |
Question 2.
Open up a used up dry cell under the guidance of your teacher/parents. Observe each part carefully.
Answer:
Do it yourself.
Question 3.
Make a holder, for a battery of two cells, using a board and metallic strips. State the purpose served by the metallic strips in this set up.
Answer:
Do it yourself.
The metallic strip serves as conducting wire between cells.
Question 4.
Select any five electric appliances/devices from your household and think of a plan for reducing their ‘electrical energy consumption’. You can make a poster giving the details of your plan. Put it up on the class bulletin board to inspire, and motivate, the other students. Be ready to discuss their suggestions/ comments.
Answer:
Do it yourself.
Question 5.
Solve the following crossword puzzle with the help of the given clues
ACROSS:
3. An insulator
5. A combination of two or more cells
6. A source of electricity
8. Path of the current
10. Allows current to pass
DOWN:
1. Does not allow current to pass
2. Completes or break the circuit
4. An expensive and good conductor of electricity
7. A source of light
9. Glows on heating
Answer:
DAV Class 6 Science Chapter 11 Solutions – Electric Currents and Circuits
I. Fill in the blanks.
Question 1.
An electric cell is a device which produces electricity because of ______
Answer:
Chemical reaction
Question 2.
An ______ gas is filled inside the bulb.
Answer:
Inert
Question 3.
The ______ of the bulb is made up of tungsten.
Answer:
Bulb
Question 4.
A switch can break or make a ______
Answer:
Circuit
Question 5.
A calculator is a device which gets power from a ______
Answer:
Battery
II. Tick (✓) the correct option.
1. Which of these components of a torch is the source of electricity?
(a) Cell
(b) Bulb
(c) Metallic case
(d’) Metallic strip
Answer:
(a) Cell
2. The filament of a bulb is made up of which material?
(a) Copper
(b) Aluminium
(c) Silver
(d) Tungsten
Answer:
(d) Tungsten
3. Which gas is filled inside the bulb?
(a) Oxygen
(b) Argon
(c) Nitrogen
(d) Hydrogen
Answer:
(b) Argon
4. How many cells make a battery?
(a) At least two
(b) At least three
(c) At least four
(d) More than ten
Answer:
(a) At least two
5. What is the SI unit of electric current?
(a) Newton
(b) Joule
(c) Watt
(d) Ampere
Answer:
(d) Ampere
III. Answer these questions.
Question 1.
Write the name of main parts of an electric torch.
Answer:
The electric torch has three main parts:
- an electric bulb
- an electric cell or a combination of electric cells (a battery) and an arrangement for housing them
- an (on/off) switch.
Question 2.
Explain the structure of a dry cell.
Answer:
A dry cell is made up of a zinc vessel which also works as the negative pole of the cell. A carbon rod is in the centre which works as the positive pole of the cell. A muslin bag is kept surrounding the carbon rod. The muslin bag is filled with manganese dioxide. The zinc vessel is filled with ammonium chloride.
Question 3.
What do you understand by LED?
Answer:
Light Emitting Diode is a simple device which emits light when electric current passes through it. LED can glow even in the presence of weak current.
Question 4.
Explain the structure of an electric bulb.
Answer:
An electric bulb is made of glass. There is a glass mount in its centre on which some support wires are attached vertically. The filament is fixed at the top of support wires. The filament is made of tungsten. Tungsten has a very high melting point which makes it ideal for a bulb filament. The filament is connected to two terminals of the bulb. An inert gas (argon) is filled inside the bulb to prevent accidental fire.
Question 5.
What are the usual components of an electric circuit?
Answer:
An electric circuit usually contains following components:
(a) A source of electricity (cell/battery).
(b) Connecting wires; which provide the path for electric current.
(c) A switch or a device which can start or stop the flow of current.
IV. Projects
Question 1.
Make a circuit diagram of a torch.
Answer:
Do it yourself.
Question 2.
Make a circuit diagram of the wiring in one of your room.
Answer:
Do it yourself.