Chemical Effects of Current

Q.

What is the EMF of a Cell?

Q. Why are tin cans used for storing food made by electroplating tin onto iron?

1. Tin reacts with food and food is protected from getting spoilt.
2. Food does not get spoilt as it does not come in contact with iron which is more reactive.
3. Tin is more reactive than iron and it acts as a preservative.
4. Iron reacts with tin to form a stable compound.

Q. Positive electrode in a cell is called as and the negative electrode is known as .

1. cathode
2. anode
3. live
4. neutral

Q.

A coating of _________is deposited on iron to protect it from corrosion and formation of rust.

1. Zinc

2. Copper

3. Gold

4. Aluminium

Q. An atom which carries a charge is known as a/an .

1. molecule
2. ion
3. element
4. compound

Q.

Which of the following methods is suitable for preventing an iron frying pan from rusting?

1. Applying grease

2. Applying paint

3. Applying a coating of zinc

4. All of the above

Q.

Why is a layer of zinc-coated over iron?

Q. Copper deposition takes place on the electrode connected to the battery terminal during the electroplating of copper electrodes.

1. positive
2. negative
3. neutral

Q.

Linking number is associated with?

Q.

Rohit has an impure copper plate and wants to purify it by electroplating. He can do this by

1. replacing the positive terminal electrode with impure copper plate

2. replacing the negative terminal electrode with impure copper plate

3. breaking the impure copper plate into 2 halves and using them as electrodes.

4. simply placing the impure copper plate in the electrolyte

Q.

Is it safe to discharge a capacitor with a screwdriver?

Q.

The diagram here shows a beaker containing a solution of copper sulphate and two carbon electrodes

A battery is placed next to it. In order that the electrode E to be plated with copper,

1. E must be connected to H and F to G

2. E must be connected to F and H to G

3. E must be connected to G and F and H

4. E and F must be connected to G

Q. The stored energy in a battery is kinetic energy.

1. True
2. False

Q.

Why zinc coating is used in iron bridges?

1. Because zinc is better conductor of heat.

2. Because zinc is less reactive than iron.

3. Because zinc is cheaper than iron.

4. Because it prevents corrosion.

Q.

Rahul has started a new shop where he sells food packed in iron containers. But he is receiving a lot of complaints about the spoilage of food. He tells his friend Rohit about this problem. Rohit suggests him to use tin coated iron instead. What could be the reason for this?

1. Because tin is a better conductor of heat. So food will remain hot.

2. Because tin is less reactive than iron.

3. Because tin is cheaper than iron.

4. Because tin is more easily available as compared to iron.

Q.

In the given arrangement, if we replace the copper plate connected to the negative terminal of the battery with a carbon rod, which of the following happens?

1. Carbon get coated on copper rod

2. Copper get coated on carbon rod

3. One of the above happens based on thickness of the rods

4. No coating happens

Q. The process of layering a material with any metal with help of electricity is called as_____.

1. Resistance
2. Conduction
3. Electroplating
4. Electrolysis

Q. Identify the electrodes in the given diagram of an electric cell:

1. 
2. 
3. 

Q. In the process of electroplating with chromium, the negative electrode can be a carbon rod.

1. False
2. True

Q. The life of a cell or a battery depends on the electrodes used in them.

1. True
2. False

Q. Tin cans are electroplated with iron to prevent rusting.

1. False
2. True

Q.
Which of the following should be placed in box 'X' to make the bulb glow more brightly?

1. Bulb
2. Cell
3. Fuse
4. Switch

Q. From where the DNA Polymerase brings DNA bases for the new strand??

Q. Which of the following statements is incorrect about an electric cell?

1. 
   An electric cell converts chemical energy into electrical energy.
2. 
   An electric cell consists of two terminals.
3. 
   The direction of flow of electrons in a cell is from positive terminal to negative terminal.
4. 
   Electric cell acts as a source to initiate current flow.

Q.

Price of battery is given in terms of

1. $Rs$ per $Wh$

2. $Rs$ per $Qty$

3. $Rs$ per $Voltage$

4. $Rs$ per $Weight$​

Q. What does a bimetallic strip consist of?

Q.

which non metals are used for making electrodes in dry cells and electric arcs?

Q.

In order to make a battery from two or more cells, the positive terminal of one cell is connected to the negative terminal of the next.

1. True

2. False

Q.

A coating of _________ is usually deposited on iron to protect it from corrosion.

1. Gold

2. Copper

3. Aluminium

4. Zinc

Q.

A common device which can supply a small electric current continuously for a sufficient time.