Question 1 :
Do you think an electromagnet can be used for separating plastic bags from a garbage heap? Explain.

Question 2 :
If the filament of the bulb is broken, would the bulb still glow?

Question 4 :
<img style='object-fit:contain' src='https://teachmint.storage.googleapis.com/question_assets/cbse_ncert/61b1cbd5f59b460d7261ecaf.jpg' /> In the circuit shown in the above figure, what will be the order in which the bulbs A, B and C will glow when the switch is moved to the ‘ON’ position?

Question 5 :
When the electric current through the fuse exceeds a certain limit, the fuse wire melts and breaks.

Question 6 :
Which of the following is the correct symbol of a switch in OFF position?

Question 8 :
The wire gets hot when an electric current passes through it. What is this effect called as?

Question 10 :
<img style='object-fit:contain' src='https://teachmint.storage.googleapis.com/question_assets/cbse_ncert/61b1cb54f59b460d7261ec1c.PNG' /> Paheli took a wire of length 10 cm. Boojho took a wire of 5 cm of the same material and thickness. Both of them connected the wires as shown in the circuit given in figure. The current flowing in both the circuits is the same. Will the heat produced be the same if the wires taken by them are of equal lengths but of different thickness? Explain.

Question 12 :
Which of the following precautions need to be taken while using electric gadgets/appliances/ circuit?

Question 13 :
Which of the following is the correct symbol of a battery?

Question 16 :
Longer line in the symbol for a cell represents its ___________terminal.

Question 17 :
On what factors the amount of heat produced in a wire depends on?

Question 18 :
Which device is used as a safety device which prevents damages to electrical circuits and possible fires?

Question 19 :
<img style='object-fit:contain' src='https://teachmint.storage.googleapis.com/question_assets/cbse_ncert/61b1cbcef59b460d7261eca6.jpg' /> A person takes the cardboard tray from inside a discarded matchbox. He wraps an electric wire a few times around the cardboard tray. Then, he places a small compass needle inside it. Now, he connects the free ends of this wire to an electric cell through a switch as shown in above figure. He notes the direction in which the compass needle is pointing and brings a bar magnet near the compass needle. He moves the switch to the ‘ON’ position. Does the compass needle deflect?

Question 21 :
Name any electric appliance where the heating effect of the electric current is used?

Question 22 :
<img style='object-fit:contain' src='https://teachmint.storage.googleapis.com/question_assets/cbse_ncert/61b1cbd6f59b460d7261ecb1.jpg' /> As shown in the above figure , Zubeda made an electric circuit using a cell holder, a switch and a bulb. When she put the switch in the ‘ON’ position, the bulb did not glow. Help Zubeda in identifying the possible defects in the circuit .

Question 23 :
<img style='object-fit:contain' src='https://teachmint.storage.googleapis.com/question_assets/cbse_ncert/61b1cbd6f59b460d7261ecb1.jpg' /> As shown in the above figure , Zubeda made an electric circuit using a cell holder, a switch and a bulb. When she put the switch in the ‘ON’ position, the bulb did not glow. Help Zubeda in identifying the possible defects in the circuit .

Question 24 :
True or False. The compass needle gets deflected when the current flows in a nearby wire.

Question 25 :
<img style='object-fit:contain' src='https://teachmint.storage.googleapis.com/question_assets/cbse_ncert/61b1cb60f59b460d7261ec26.PNG' /> Paheli took a wire of length 10 cm. Boojho took a wire of 5 cm of the same material and thickness. Both of them connected the wires as shown in the circuit given in the figure above. The current flowing in both the circuits is the same. Will the heat produced in both the cases be equal? Explain.

Question 26 :
What property of conducting wires is ideal for making electric fuses?

Question 28 :
In an electric circuit a fuse is a ________ to prevent possible fire.

Question 29 :
A current carrying coil of an insulated wire wrapped around a piece of iron is called an electromagnet. State true or false .

Question 32 :
Which of the following precautions need to be taken while using electric gadgets/appliances/ circuit?

Question 33 :
When an electric current flows through a wire, it behaves like a magnet. State true or false .

Question 34 :
The combination of two or more cells is called a ____________.

Question 36 :
Which of the following is the correct symbol of an electric cell?

Question 37 :
Name the device used these days in place of electric fuses in electrical circuits.

Question 38 :
<img style='object-fit:contain' src='https://teachmint.storage.googleapis.com/question_assets/cbse_ncert/61b1cbcdf59b460d7261eca4.jpg' /> A person takes the cardboard tray from inside a discarded matchbox. He wraps an electric wire a few times around the cardboard tray. Then, he places a small compass needle inside it. Now, he connects the free ends of this wire to an electric cell through a switch as shown in above figure. He notes the direction in which the compass needle is pointing and brings a bar magnet near the compass needle. He moves the switch to the ‘ON’ position. Move the switch back to the ‘OFF’ position. Does the compass needle come back to its initial position?

Question 39 :
Are the batteries used in tractors, trucks and inverters also made from cells?

Question 42 :
<img style='object-fit:contain' src='https://teachmint.storage.googleapis.com/question_assets/cbse_ncert/61b1cbd2f59b460d7261ecab.jpg' /> A person takes around 75 cm long piece of insulated (plastic or cloth covered or enamelled) flexible wire and an iron nail, say about 6–10 cm long. He winds the wire tightly around the nail in the form of a coil. Now, he connects the free ends of the wire to the terminals of a cell through a switch as shown in above figure. Next, he places some pins on or near the end of the nail. Now, he switches on the current. Do the pins cling to the tip of the nail?

Question 43 :
<img style='object-fit:contain' src='https://teachmint.storage.googleapis.com/question_assets/cbse_ncert/61b1cb54f59b460d7261ec1c.PNG' /> Paheli took a wire of length 10 cm. Boojho took a wire of 5 cm of the same material and thickness. Both of them connected the wires as shown in the circuit given in figure. The current flowing in both the circuits is the same. Will the heat produced be the same if the wires taken by them are of equal lengths but of different thickness? Explain.

Question 44 :
Do you think an electromagnet can be used for separating plastic bags from a garbage heap? Explain.

Question 45 :
<img style='object-fit:contain' src='https://teachmint.storage.googleapis.com/question_assets/cbse_ncert/61b1cb50f59b460d7261ec1a.PNG' /> When an electric current flows through a wire AB as shown in the figure, the wire?

Question 46 :
Choose the statement which is correct in the case of an electric fuse.

Question 49 :
<img style='object-fit:contain' src='https://teachmint.storage.googleapis.com/question_assets/cbse_ncert/61b1cbcbf59b460d7261eca2.jpg' /> A person makes the circuit as shown in the above figure. However, he replaces the cell with a battery of four cells. Also, in place of the nichrome wire, he ties a thin strand of steel wool. (The steel wool is commonly used for cleaning utensils and is available in grocery shops.) If there are any fans in the room, he switches them off. Now, he passes the current through the circuit for sometime. Does the strand of steel wool melt and break?

Question 50 :
Choose the statement which is not correct in the case of an electric fuse.