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Basic Knowledge of Electrical Symbols

Q: Identify the circuit (Figure 12.3) in which the electrical components have been properly connected

Hint: Check the connections of the Voltmeter and Ammeter.Step 1: Checking if the Voltmeter is connected in parallel and Ammeter is connected in series. In circuits \\((i)\\) and \\((iii)\\), Voltmeter is connected in series. In circuit \\((iii)\\) the ammeter is connected in parallel. In circuits \\((i)\\) and \\((iii)\\), connections are not proper. In circuits \\((ii)\\) and \\((iv)\\), the Voltmeter and Ammeter are connected in parallel and series respectively. Step 2: Checking if the terminals are connected properly. In circuit \\((iv)\\), the positive terminal of the ammeter is connected with the negative terminal of the cell. Hence it is not proper. Whereas in circuit \\((ii)\\), all the terminals are properly connected. Therefore option \\((B)\\) is the correct option.

Q: When a switch is in OFF position, i) Circuit starting from the positive terminal of the cell stops at the switch.ii) Circuit is open.iii) No current flows through it.iv) Current flows after some time.Choose the combination of correct answer from the following.

When the switch of a circuit is in off position, the circuit will remain open and in this condition, the current does not flow through the circuit.So, option (II) and (III) are correct.

Q: A rheostat is used in an electrical circuit

A rheostat is a variable resistor which is used to control current. they are able to vary the resistance in circuit without interruption. the construction of a rheostat is very similar to potentiometer .Thus A rheostat is used in circuit to change the resistance of the circuit. so option correct is A.

Q: A switch is an on-off device in an electric circuit.

An electrical switch is any device used to interrupt the flow of electrons in a circuit. Switches are essentially binary devices: they are either completely on (“closed”) or completely off (“open”).

Q: In the circuit shown in the figure.I)Would any of the bulb glow when the switch is in the 'OFF' position?II) What will be the order in which the bulbs A, B and C will glow when the switch is moved to the 'ON' position?

\\(I)\\) No, none of the bulbs will glow when the switch is the off position as the circuit won't be completed when the switch will be in the off state.\\(II)\\) All the bulbs will glow at once because all the bulbs are connected with the same battery and they are being controlled by the same switch.

Q: Name a device that helps to maintain a potential difference across a conductor.

\\(\textbf{Explanation}\\)\\(\bullet\\)Potential difference is the difference of electrical potential between two points which is defined as the amount of work energy is required to move an electric charge from one point to another.\\(\bullet\\)An electric cell or battery helps to maintain a potential difference across a conductor.\\(\bullet\\)The cells only provide the energy required to work on the charge in order to transport it from the negative to the positive terminal. \\(\bullet\\)The cell can sustain an electric potential difference across the two ends of the external circuit by giving energy to the charge.

Q: The main function of a switch is to

A switch is a device that is used for making and breaking electric current in a circuit. It is used to turn on and turn off daily used equipment like television, washing machine, fan, light, etc.

Q: Where should we place the key or switch in the electric circuits?

The key or Switch can be placed anywhere in the electric circuit.

Q: What is symbol of battery?

First option is the symbol of battery. The short and longer bar represent the negative and positive terminals respectively of each cell in the battery.Answer-(A)