1. Electric current can result in
(A) just a heating effect.
(b) only a chemical effect.
(c).simply the magnetic effect
(d) the effects of chemicals, heat, and magnetism.
1. Electric current can result in
(A) just a heating effect.
(b) only a chemical effect.
(c).simply the magnetic effect
(d) the effects of chemicals, heat, and magnetism.
Explanation:
The right response is (d).effects that are chemical, thermal, and magnetic.
A chemical reaction takes place when an electric current passes through a conducting solution. This is the chemical action of electric current.
when an electrical current is passing through the lightbulb. The lightbulb starts to glow when the filament gets hot. This is the heating effect of electric current.
When an electric current passes through a circuit, a magnetic field is produced all around it. This is how an electric current's magnetic effect appears.
2. As seen in Fig.14.1, Boojho and Paheli conducted studies using comparable bulbs and cells but two distinct solutions, A and B
They discovered that setup A's bulb lights brighter than setup B's does. Hence, you would say
(A) The circuit in setup A is experiencing a greater current flow.
(b) The circuit in setup B is experiencing a greater current flow.
(c) The two circuits are receiving an equal amount of current.
(d) This comparison cannot be made between the current flowing through the circuits in the two systems.
2. As seen in Fig.14.1, Boojho and Paheli conducted studies using comparable bulbs and cells but two distinct solutions, A and B
They discovered that setup A's bulb lights brighter than setup B's does. Hence, you would say
(A) The circuit in setup A is experiencing a greater current flow.
(b) The circuit in setup B is experiencing a greater current flow.
(c) The two circuits are receiving an equal amount of current.
(d) This comparison cannot be made between the current flowing through the circuits in the two systems.
Explanation:
The circuit in setup A is experiencing a greater current flow, hence the answer is (a).
As solution A is a better conductor of electricity than solution B, a higher current is flowing through the circuit in setup A.
A weak current through the solution in setup B can prevent the bulb from glowing brightly. The liquid in setup A, however, receives a powerful enough current to for the bulb to shine brilliantly.
Thus, setup A's circuit is experiencing a greater current flow.
3. In his hamlet, Boojho's uncle has established an electroplating plant. He has to get rid of the manufacturing garbage.
(a) in a river close by.
A) in the neighbourhood pond.
(c) in the cornfield next door.
(d) in accordance with the local authority's disposal policies.
3. In his hamlet, Boojho's uncle has established an electroplating plant. He has to get rid of the manufacturing garbage.
(a) in a river close by.
A) in the neighbourhood pond.
(c) in the cornfield next door.
(d) in accordance with the local authority's disposal policies.
Explanation:
According to the local authority's disposal rules, the correct response is (d)
(d) in accordance with the local authority's disposal policies.
In the electroplating business, waste disposal is a serious problem since it pollutes water and discharges a dangerous chemical into bodies of water. So, it should be disposed of in accordance with the local authority's regulations. Because electroplating waste is hazardous by nature, it must be disposed of in accordance with the law.
4. A conducting solution undergoes a colour shift when an electric current is conducted through it. This proves.
(A) Current's chemical effects.
(b) the impact of current's heating.
(c).the magnetic impact of current.
(d) the current's lightning effect.
4. A conducting solution undergoes a colour shift when an electric current is conducted through it. This proves.
(A) Current's chemical effects.
(b) the impact of current's heating.
(c).the magnetic impact of current.
(d) the current's lightning effect.
Explanation:
The answer is (a) current's chemical effects.
Chemical reactions are brought on by running an electric current through a solution. Electric current has a chemical action that results in a change in colour. Chemical reactions are brought on by running an electric current through a solution. Electric current has a chemical action that results in a change in colour.
5. Which of the following remedies won't allow electricity to flow?
(a) lemon juice
(b)vinegar
(c)Tap water
(d). Vegetable oil
5. Which of the following remedies won't allow electricity to flow?
(a) lemon juice
(b)vinegar
(c)Tap water
(d). Vegetable oil
Explanation:
conductive materials: Materials with a high electron mobility are considered conductors, whereas materials with a low electron mobility are considered insulators.
Materials that make it easy for electricity to flow through them are called electrical conductors.
When two distinct types of materials are compared, a substance is said to be a good conductor of electricity if the first one allows more electricity to travel through it.
An electrical conductor is easily capable of carrying electric charges. The ability of a conductor to transport electricity is referred to as conductivity.
Vegetable oil cannot conduct electricity because it lacks ions.
Thus, Option (D) is the proper answer.
6. Which of the following metals is electroplated onto things to give them the appearance of shine?
(a) iron
(b)Copper
(c) Chromium
(d) Aluminum
6. Which of the following metals is electroplated onto things to give them the appearance of shine?
(a) iron
(b)Copper
(c) Chromium
(d) Aluminum
Explanation:
Chrome C is the appropriate answer.
Electroplating:
Electroplating is the practise of aligning one metal onto another.
An electroplating equipment is used for this, which consists of a brine solution, a battery, wires, and alligator clips. The apparatus also includes carbon rods that are fastened to the metals that need to be electroplated and layered.
Chromium is used in electroplating to give items a shining look because it shines and is scratch-resistant.
Option is the best response (C).
7. Which of the following solutions will not make the bulb in Fig 14.2 glow?
(a) sodium chlorides
(b) copper sulphate
(c) silver nitrate
(d) sugar solution in distilled water
7. Which of the following solutions will not make the bulb in Fig 14.2 glow?
(a) sodium chlorides
(b) copper sulphate
(c) silver nitrate
(d) sugar solution in distilled water
Explanation:
The solution of sugar in water that has been diluted is (d).
The sugar solution cannot ionise to conduct electricity because it is neither acidic nor basic. The absence of ions in distilled water makes it incapable of conducting electricity. As a result, distilled water and sugar solution won't conduct electricity. A bulb won't glow because sugar is an organic compound that does not break down or produce any charges in a water solution. Because there are no charge particles in the solution, there is no conduction of electricity.
8. .Fill in the blanks
(a) The object to be electroplated is taken as ____________ electrode.
(b) One of the most common applications of chemical effect of electric current is ______________.
(c) Small amount of a mineral salt present naturally in water makes it a______________ of electricity.
(d) Electroplating of ______________ is done on objects like water taps and cycle bell to give them a shiny appearance.
8. .Fill in the blanks
(a) The object to be electroplated is taken as ____________ electrode.
(b) One of the most common applications of chemical effect of electric current is ______________.
(c) Small amount of a mineral salt present naturally in water makes it a______________ of electricity.
(d) Electroplating of ______________ is done on objects like water taps and cycle bell to give them a shiny appearance.
Explanation:
(a) The object to be electroplated is taken as a Cathode electrode.
Explanation:
The metal that has to be electroplated is always fashioned into a cathode because it cannot dissolve or oxidise throughout the process. The metal that will be electroplated is placed in the electrolyte solution as an electrolyte, and the metal ions in it decrease at the cathode to produce a coating on the metal.
(b) One of the most common applications of chemical effect of electric current is Electroplating
Explanation:
Electroplating is the technique by which an electric current deposits a coating of the chosen metal over another material. It is the most practical and widespread application of how electric current has chemical effects. In the industrial setting, it is widely used to coat metal items with the required layer of another metal.
(c) Small amount of a mineral salt present naturally in water makes it a Conductor of electricity.
Explanation:
Depending on the amount of current flowing through the circuit, the rate at which the anode dissolves is equal to the rate at which the cathode is plated. The anode continuously replenishes the ions in the electrolyte bath in this way. Water is an excellent conductor of electricity because it contains a little quantity of a mineral salt that occurs naturally.
Water naturally contains a little quantity of a mineral salt that turns it into a salt solution and makes it an excellent conductor of electricity.
(d) Electroplating of Chromium is done on objects like water taps and cycle bell to give them a shiny appearance.
Explanation:
Electroplating:
Electroplating is the process of joining two different metals together.An electroplating system is needed to do this, which includes a battery, a brine solution, some wires, and alligator clips that hold carbon rods attached to the metals that need to be electroplated and stacked.Anode and cathode are other names for rods.Electroplating is often used to improve the metal in any way.Chromium is electroplated on devices like bicycle bells and water taps to give them a brilliant look.
9. Why is a layer of zinc-coated over iron?
9. Why is a layer of zinc-coated over iron?
Explanation:
Rust is easily created when iron and air are combined. Iron is covered with zinc to stop it from rusting. Rust is a combination of iron that is created when iron objects react with oxygen and moisture. Iron artefacts lose its permeability, strength, and aesthetic appeal due to rust.
Hence, a zinc coating is put to things made of iron to stop them from rusting.
Galvanization is the process of applying a zinc layer over iron things.
10. Will the solution of sugar in distilled water conduct electricity?
10. Will the solution of sugar in distilled water conduct electricity?
Explanation:
No, just distilled water.
Reason: Sugar doesn't carry electricity.
Covalent molecules are formed when it dissolves in water.
It does not transmit electricity like salt or other ionic compounds since it is a covalent molecule.
Just 10 -7 mol/L of H + and 10 -7 mol/L of OH- are present in distilled water.
There is incredibly little ionisation present here.
Water is frequently referred to be a nonconductor because of how little current it conducts.
While making the sugar solution using tap water, the ions will boost the conductivity by around 500-fold.
The ability to conduct electricity in the sugar solution is possessed by the water, not by the sugar itself.
11. Identify the current effect that causes the light bulb to glow in an electric circuit.
11. Identify the current effect that causes the light bulb to glow in an electric circuit.
Explanation:
The tungsten filament inside the electric bulb glows and heats up when electricity flows through it.
Electric current, electron drift caused by the current, and the resistance it has all contribute to the generation of this heat.
Hence, the glow of the bulb in an electric circuit is caused by the heating impact of electric current.
12. Boojho built the circuit shown in Fig. 14.3 and noticed the lightbulb wasn't glowing. He expanded the circuit by one cell at Paheli's advice. The light is presently on. Explain.
12. Boojho built the circuit shown in Fig. 14.3 and noticed the lightbulb wasn't glowing. He expanded the circuit by one cell at Paheli's advice. The light is presently on. Explain.
Explanation:
One cell's inability to produce enough voltage for the current to allow the bulb to glow initially prevented the bulb from starting to glow. The voltage across the circuit doubles with the addition of each additional cell, up to a level where the current may be increased. This current heats the bulb filament sufficiently, causing the bulb to light.
13. As seen in Fig. 14.4, Paheli set up an experiment employing liquid A in the beaker. She saw the light bulb is glowing. She then swapped out liquid A with liquid B. The light bulb did not shine this time. Boojho recommended using an LED in place of the lightbulb. The LED lights, they noticed. Explain.
13. As seen in Fig. 14.4, Paheli set up an experiment employing liquid A in the beaker. She saw the light bulb is glowing. She then swapped out liquid A with liquid B. The light bulb did not shine this time. Boojho recommended using an LED in place of the lightbulb. The LED lights, they noticed. Explain.
Explanation:
Liquid A in this experiment had to be a good conductor of electricity and enable the greatest current to flow through it in order for the bulb to light.
But, when it is changed with a different liquid B, the bulb might not light up because there may not be enough current flowing through the liquid B to illuminate the bulb.
When it is replaced with a different liquid B, the bulb does not light because the liquid B's weak current would not have allowed the bulb to illuminate. Nonetheless, the modest amount of current that is flowing through B is sufficient to light a low voltage LED, which is why the LED is lit.
14. Paheli wants to embellish an iron spoon with silver decorations. She used a silver nitrate (AgNO3) solution in a beaker to construct a simple electroplating circuit. What terminal on the battery should the spoon be connected to? What sort of substance should be applied to the other electrode?
14. Paheli wants to embellish an iron spoon with silver decorations. She used a silver nitrate (AgNO3) solution in a beaker to construct a simple electroplating circuit. What terminal on the battery should the spoon be connected to? What sort of substance should be applied to the other electrode?
Explanation:
The spoon must be connected to the battery's negative terminal. Silver is required to be used in the second electrode. Paheli must apply silver to the iron spoon using a second silver-based electrode. The negative terminal of the battery must be connected to the battery using an iron spoon. The iron spoon was covered with silver after being put on the silver nitrate and dissolved in it.
15. Why does tin have to be electroplated onto iron to create food-storage cans?
15. Why does tin have to be electroplated onto iron to create food-storage cans?
Explanation:
Then iron, tin is less reactive. Tin is put over iron while food is being stored to stop iron from interacting with the food.
Because tin is less reactive than iron and is thus utilised for food containerization, tin cans are manufactured by electroplating tin onto iron. Food is therefore kept from coming into touch with iron and is guarded against deterioration. Iron is therefore covered in a layer of zinc to prevent corrosion and rust development.
16. Which one of these two circuits, A or B, exhibits the proper observation?
16. Which one of these two circuits, A or B, exhibits the proper observation?
Explanation:
These are two circuits and two potato halves.
Each circuit's two terminals are put into one of the potato halves.
Each potato has two greenish-blue dots on it.
We are aware that the battery's larger line (current source) is the positive (+) terminal, and its smaller line is the negative (-) terminal.
We conduct an experiment in which three potatoes are split in half, and copper test wires are inserted.
After some time, it was discovered that only the positive terminals, not the negative terminals, create the greenish-blue dots.
Hence, based on our observations, we may conclude that the positive battery terminals that were placed into the potatoes are where all of the greenish-blue dots are created.
This experiment may be used to determine which battery terminal is the positive one.
The proper observation is therefore observation A. Around the positive terminals of the battery that was placed into the potatoes, greenish-blue patches form.
17. The ensuing circuits should be carefully observed. Which circuit will the light be on in? Fill in the blanks along each of the circuits shown in Fig. 14.6 with "Yes" or "No."
17. The ensuing circuits should be carefully observed. Which circuit will the light be on in? Fill in the blanks along each of the circuits shown in Fig. 14.6 with "Yes" or "No."
Explanation:
Option (D) (D)
Steel is an alloy of metals and a reliable conductor of current.
It can close the gap in the circuit.
The circuit's bulb will illuminate where the steel gap is linked.
Option (B): Iron is used to make nails. Iron is a superior conductor of current.
It can close the gap in the circuit. And the light will come on in this circuit.
both option (A) and (C)
Both coal and a rubber are poor electrical conductors.
The circuit's bulb that is connected to the gap via coal and rubber is dark.
Option (B) and option (D) are the proper answers.
18. A conductive solution is subjected to an electric current. Name three potential observations.
18. A conductive solution is subjected to an electric current. Name three potential observations.
Explanation:
The following changes may be seen when an electric current is sent through a conducting solution:
Gas bubbles might burst at the electrodes.
The electrodes may have metal deposits.
You can notice a change in the electrolytic solution's colour.
The solution can heat up.
19. Boojho noticed that the electrode linked to the battery's negative terminal deposits copper in the circuit shown in Fig. 14.7. Paheli attempted the same experiment once more. She could only locate one copper plate, though. Thus, using a carbon rod as a negative electrode, she took action. Will the carbon rod still be coated with copper? Describe your response.
19. Boojho noticed that the electrode linked to the battery's negative terminal deposits copper in the circuit shown in Fig. 14.7. Paheli attempted the same experiment once more. She could only locate one copper plate, though. Thus, using a carbon rod as a negative electrode, she took action. Will the carbon rod still be coated with copper? Describe your response.
Explanation:
Indeed, copper will be deposited on the carbon rod from the copper sulphate solution. For electroplating, copper from the copper plate will be dissolved in copper sulphate solution. On the carbon rod, copper from the copper sulphate solution will be deposited. When an electric current is run through a copper sulphate solution, copper and sulphate separate apart. Free copper is pulled to the electrode—a carbon rod—that is attached to the battery's negative terminal and deposits itself there. Paheli will therefore acquire a copper covering on carbon rod.
20. This circuit was built up by Boojho to purify copper. What will the composition of plate A, plate B, and the solution be? Describe the cleansing procedure.
20. This circuit was built up by Boojho to purify copper. What will the composition of plate A, plate B, and the solution be? Describe the cleansing procedure.
Explanation:
Pure copper is on plate A. Impure copper is in plate B. The solution is a copper sulphate solution.
Electroplating is the purifying process used here.
Take two copper plates that are about 10 cm by 4 cm each, along with some copper sulphate. Into a clean, dry beaker, add 250 mL of distilled water. It has to have two tablespoons of copper sulphate dissolved in it.To increase the conductivity of the copper sulphate solution, add a few drops of diluted sulfuric acid. Use sandpaper to polish copper plates. After washing them with water, dry them. Attach the battery's terminals to the copper plates, then submerge them in a copper sulphate solution.Copper sulphate separates into copper and sulphate when an electric current is run through the copper sulphate solution. Free copper is attracted to and deposited on the electrode that is attached to the battery's negative terminal.
21. If there is a space between the two wires, the circuit cannot conduct current. Does this suggest that air is a poor electrical conductor? Can electricity ever flow through air? Explain.
21. If there is a space between the two wires, the circuit cannot conduct current. Does this suggest that air is a poor electrical conductor? Can electricity ever flow through air? Explain.
Explanation:
Air often performs poorly as an electrical conductor. However under other circumstances, such as during lightning, air conducts electricity. Absolutely, air is a poor conductor of electricity if current cannot pass through the space between the wires.
No, air only conducts electricity under certain conditions, such as high voltage or airborne moisture, such during lightning. If there is no current running through the space between the wires, air is not a good conductor of electricity. No, only at high voltages does air carry electricity.No, air only conducts electricity in conditions of high voltage or wetness, such as during lightning.
22. The circuit seen in Fig. 14.10 was created by Boojho. He was interested in learning what transpired when an electric current was run through water. Nevertheless, he neglected to mix a few drops of lemon juice into the water. Will it affect his perceptions in any way? Explain.
22. The circuit seen in Fig. 14.10 was created by Boojho. He was interested in learning what transpired when an electric current was run through water. Nevertheless, he neglected to mix a few drops of lemon juice into the water. Will it affect his perceptions in any way? Explain.
Explanation:
No, even if there isn't any lemon juice added and the water is distilled, current will still flow through the circuit. A tiny current will flow through the circuit if the water is salty. A few drops of lemon juice in water will boost the solution's conductivity and make it easier for a lot of electricity to flow. If the water is distilled, it cannot conduct electricity without lemon juice, hence current cannot flow across the circuit.A weak current will flow through circuits if the water is salty, and bubbles will be visible on the negative electrode.
23. Boojho adjusted the circuit as indicated in Fig. 14.11 B after noticing that the bulb was not glowing in the circuit depicted in Fig. 14.11 A. The magnetic compass showed deflection, he noticed. What does the magnetic compass's deflection mean?
(ii) Why didn't the lightbulb in Fig. 14.11 A glow?
(iii) What would happen if there were more turns in the coil in Fig. 14.11B that is coiled around the magnetic compass?
(iv) What will happen to the circuit in Fig. 14.11B if there are more cells added?
23. Boojho adjusted the circuit as indicated in Fig. 14.11 B after noticing that the bulb was not glowing in the circuit depicted in Fig. 14.11 A. The magnetic compass showed deflection, he noticed. What does the magnetic compass's deflection mean?
(ii) Why didn't the lightbulb in Fig. 14.11 A glow?
(iii) What would happen if there were more turns in the coil in Fig. 14.11B that is coiled around the magnetic compass?
(iv) What will happen to the circuit in Fig. 14.11B if there are more cells added?
Explanation:
Hint: The amount of current flowing and the number of turns in the coil coiled around the magnetic compass determine the amount of deflection.
I The deviation in the magnetic compass shows that the circuit is conducting current. The magnetic effect created by the current causes the compass needle to deviate.
(ii) Because of the circuit A's weak current flow, the lightbulb did not illuminate. The filament of the light bulb does not heat up enough and does not shine if the current flowing through the circuit is weak. This suggests that the solution is a poor electrical conductor.
(III) The magnetic influence of the current surrounding the magnetic compass will increase needle deflection if we increase the number of rotations.
(IV) If we add more cells to the circuit, the electric current that flows through it will be considerably stronger, increasing the needle's deflection.
24. A magnetic compass, an empty matchbox, a battery with two cells, and connecting cables are all given to you. How can you create a tester for checking an electric circuit with these items? Explain and draw the appropriate circuit schematic.
24. A magnetic compass, an empty matchbox, a battery with two cells, and connecting cables are all given to you. How can you create a tester for checking an electric circuit with these items? Explain and draw the appropriate circuit schematic.
Explanation:
Electric circuit testing:
The electrical circuit looks like this:
A magnetic field in the form of a ring coils around a straight conductor as current flows through it.
The magnetic field that is created around the wire while current is flowing through the circuit causes the compass needle to be deflected. The thumb rule on the right hand side indicates the direction.
The magnetic compass needle deviates as current flows across the circuit due to the current's magnetic impact.
