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Study about cells - class-XI

Description: study about cells
Number of Questions: 19
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Tags: chemical effects of electric current physics electric current through conductors electricity
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Filament of torch bulb is ?

  1. A metal case

  2. Metal tip at the centre of the base

  3. 2 thick wires

  4. Thin wires


Correct Option: D
Explanation:

A filament of a bulb is spirally wounded wire inside the bulb supported by two thick wires at its ends. The filament is wire, which is mostly made up of tungsten. 

As electric current passes through the filament, it glows to produce light.

An inductor coil stores $U$ when a current is passed through it and dissipates heat energy at the rate of $P .$ The time constant of the circuit when this connected across a battery of zero internal resistance is:


  1. $\frac { 4 U } { P }$

  2. $\frac { U } { P }$

  3. $\frac { 2 U } { P }$

  4. $\frac { 2 P } { 6U }$


Correct Option: C

An electric circuit which starts from one terminal of a cell and ends at the other terminal of the cell without any break is called:

  1. open electric circuit

  2. closed electric circuit

  3. complete electric circuit

  4. both b and c


Correct Option: D

Five cells each of emf $\varepsilon $ and internal resistance r each are connected in series. If one cell is connected wrongly, then potential difference across this cell will be

  1. $\dfrac { 8\varepsilon }{ 5 } $

  2. zero

  3. $\dfrac { 4\varepsilon }{ 5 } $

  4. $\dfrac { 2\varepsilon }{ 5 } $


Correct Option: C

State whether given statement is True or False
We use battery cell in our everyday life ?

  1. True

  2. False


Correct Option: A
Explanation:

We use battery cell in everyday life. This statement is true because battery cell is used on daily devices like remotes,Clocks, torch etc.

A wire of length $L$ and $3$ identical cells of negligible internal resistances are connected in series. Due to the current, the temperature of the wire is raised by $\Delta\ T$ in a time $t$. A number $N$ of similar cells is now connected in series with a wire of the same material and cross-section but of length $2\ L$. The temperature of the wire is raised by the same amount $\Delta\ T$ in the same time. The value of $N$ is

  1. $4$

  2. $6$

  3. $8$

  4. $9$


Correct Option: B

Two cells of emf's $3V$ and $3V$ have internal resistances  $1.5\Omega\ &\ 1\Omega$ are connected in parallel across $3\Omega,$ such that they send the current through $3\Omega$ in same direction calculate the p.d. across $3\Omega$ resistor.

  1. 3V

  2. 4V

  3. 1.5V

  4. 2.5V


Correct Option: A

How many cells each marked ( 12V - A) should be connected  in mixed  grouping  so that it may be marked as ( 48 V- 18 A)  

  1. 4

  2. 8

  3. 12

  4. 16


Correct Option: A

Why the bulb brighter in a simple circuit that has more cells?

  1. Because the flow of electricity is more

  2. Because the flow of electricity is same

  3. Because the flow of electricity is less

  4. None of these


Correct Option: A

Two Leclanche cells assisting each other could be balanced on a length $L$ of a potentiometer wire. If the current through the wire is halved, what will be balancing length for one Leclanche cell?

  1. $L/4$

  2. $L/2$

  3. $L$

  4. $2L$


Correct Option: B

The two ends of a copper conductor of length 3.2 cm are connected to a battery acceleration of free electrons is

  1. $ 2 \times 10^{14} ms^{-2} $

  2. $ 3 \times 10^{14} ms^{-2} $

  3. $ 4 \times 10^{14} ms^{-2} $

  4. $ 5 \times 10^{14} ms^{-2} $


Correct Option: A

A cell in which chemical energy is converted into electric energy by first passing a current through it is called a _________.

  1. Primary cell

  2. Secondary cell

  3. Photocell

  4. Electrostatic machine


Correct Option: A
Explanation:

The cell in which chemical energy is converted into electrical energy is called a primary cell. Leclanche cell, Daniel cell, Voltaic cell are all primary cells and not the storage cells.

What is the $-$ve terminal of dry cell made up of?

  1. Carbon rod

  2. Zinc plate

  3. Magnesium plate

  4. Cadmium rod


Correct Option: B
Explanation:
The dry cell consists of a zinc can, electrolyte paste, and a carbon rod in the center. A chemical reaction takes place between the zinc can and the paste. Electrons flow from the negative (zinc) terminal to the positive (carbon) terminal. Electrons are then pumped back to the negative terminal.

In secondary cells:

  1. Chemical changes can be reversed by heating electrodes

  2. Chemical changes can be reversed by passing electric current

  3. Current is produced by photo chemical reactions

  4. None of these


Correct Option: B
Explanation:

Answer is B.

When a primary cell is used, chemical reactions in the battery use up the chemicals that generate the power; when they are gone, the battery stops producing electricity and is useless. In contrast, in a secondary cell, the reaction can be reversed by running a current into the cell with a battery charger to recharge it, regenerating the chemical reactants. 

Three types of electric cells which provide current are:

  1. Button cell, solar cell & secondary cell

  2. Solar cell, electrolytic cell, electro chemical cell

  3. $(A)$ and $(B)$ both are correct

  4. Neither $(A)$ nor $(B)$ is correct


Correct Option: C
Explanation:

Answer is C.

When a primary cell is used, chemical reactions in the battery use up the chemicals that generate the power; when they are gone, the battery stops producing electricity and is useless. In contrast, in a secondary cell, the reaction can be reversed by running a current into the cell with a battery charger to recharge it, regenerating the chemical reactants. 
The types of cells mentioned in option A and option are correct.
Hence, option C is correct.

What is the direction of flow of current inside a dry cell?

  1. from $+$ve to $-$ve terminal

  2. from $-$ve to $+$ve terminal

  3. from $+$ve to $+$ve terminal

  4. from $-$ve to $-$ve terminal


Correct Option: B
Explanation:
The dry cell consists of a zinc can, electrolyte paste, and a carbon rod in the center. A chemical reaction takes place between the zinc can and the paste. Electrons flow from the negative (zinc) terminal to the positive (carbon) terminal. Electrons are then pumped back to the negative terminal.

The cartridge in a dry cell contains :

  1. manganese dioxide and ammonium chloride

  2. manganese dioxide and zinc dust

  3. ammonium chloride and zinc dust

  4. manganese dioxide and activated carbon


Correct Option: D
Explanation:

The cartridge in a dry cell contains manganese dioxide and activated carbon .

State whether true or false.
In a dry cell, the zinc container acts as the positive electrode.

  1. True

  2. False


Correct Option: B
Explanation:

In a dry cell, the zinc container acts as positive electrodes.T his statement is false.

The longer lead of a LED is always connected to the negative terminal of the battery and the shorter lead is connected to the posltlve terminal of the battery

  1. True

  2. False

  3. Ambiguous

  4. Data insufficient


Correct Option: B
Explanation:

Answer is B.
The LED bulb has two leads. The lead connected to the positive terminal of battery is called anode and the lead connected to the negative terminal is cathode. The slightly longer lead than the other is always connected to the positive terminal and the shorter lead is connected to the negative terminal.
Hence, the given statement is false.

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