Q: What is the power produced by an appliance marked " \$240 V\$, \$2 A"?\$

Relation between power\$(P)\$, voltage\$(v)\$ and current\$(I)\$-\$ P = VI\$Given,\$V = 240\ V\$\$I = 2\ A\$\$\Rightarrow P = 240 \times 2\$\$\Rightarrow P = 480\ W\$

Q: An electric bulb works on \$230\ V\$ line and draws \$0.1\ A\$ current. The resistance of the filament is:

Voltage, \$V=230\ V\$Current, \$I = 0.1\ A\$According to Ohm's law,\$ V = IR\$\$\Rightarrow R = \dfrac{V}{I}\$ \$ = \dfrac{230}{0.1}\$\$ \Rightarrow R = 2300\ \Omega\$

Q: Which one of the following is not the unit of energy?

\$\textbf{Hint:}\$ Use the relation between energy and power.\$\textbf{Explanation :}\$If Watt is unit of power then kilowatt is also the unit of power.Work done = Force ×× Distance = Newton - metre, Therefore it is the unit of Work or Energy.Energy = Power ×× time = kilowatt - hour, in fact it is the commercial unit of Energy.

Question 1

What is the power produced by an appliance marked &#34; $240 V$, $2 A&#34;?$

Accepted Answer

Relation between power$(P)$, voltage$(v)$ and current$(I)$-$ P = VI$Given,$V = 240\ V$$I = 2\ A$$\Rightarrow P = 240 \times 2$$\Rightarrow P = 480\ W$

Question 2

A $24 \ V$ potential difference is applied across a parallel combination of four $6 \ \Omega$ resistor. The current in each resistor is:

Accepted Answer

Since the resistors are connected in parallel,the voltage across each resistor is the same ,i.e $24 \ V$.Therefore, current in each resistor can now simply be calculated using the relation,$ I = \dfrac{V}{R}  \implies I = \dfrac{24}{6.0} = 4.0 \  A $

Question 3

Electric current is to be passed from one body to another. For this purpose the two bodies must be joined by

Accepted Answer

Copper wire being a conductor can conduct .

Question 4

The flow of the electric current through a metallic conductor is:

Accepted Answer

Protons and neutrons are strongly bound to the atoms (in the nucleus). Only electrons can be free from atoms. The systematic flow of these free electrons constitutes a current.  Therefore, the electric current is only due to the flow of electrons.

Question 5

In a metallic conductor, electric current is thought to be due to the movement of:

Accepted Answer

Current is due to flow of charged particles. Current flow can be due to movement of ions or electrons. In metals, however, the protons are bounded and hence electrons are the only contributors to current.

Question 6

An electric bulb works on $230\ V$ line and draws $0.1\ A$ current. The resistance of the filament is:

Accepted Answer

Voltage, $V=230\ V$Current, $I = 0.1\ A$According to Ohm's law,$  V = IR$$\Rightarrow  R = \dfrac{V}{I}$            $ = \dfrac{230}{0.1}$$ \Rightarrow  R = 2300\  \Omega$

Question 7

Which of the following option has no effect on an electric fuse wire?

Accepted Answer

A fuse is a safety device that provides overcurrent protection, to an electrical circuit. Its essential component is a metal wire or strip that melts when too much current flows through it, interrupting the current that it connects.Therefore the working of the fuse depends upon its resistance and current flowing through it.Hence, the correct option is C.

Question 8

Four identical wires each having resistance $R$ are connected as shown in the figure. Equivalent resistance between A and B is:

Accepted Answer

Simplified circuit is drawn. It is the series combination of the four resistances.$ R_{AB} = 4R$

Question 9

When we pay for our electricity bill, we are paying for the:

Accepted Answer

Electricity bill is measured in units where 1 unit is equal to kWh which is the unit of energy. Hence, when we pay for our electricity bill, we pay for the amount of electrical energy consumed by us.

Question 10

Which one of the following is not the unit of energy?

Accepted Answer

$\textbf{Hint:}$ Use the relation between energy and power.$\textbf{Explanation :}$If Watt is unit of power then kilowatt is also the unit of power.Work done = Force &#215;&#215; Distance = Newton - metre, Therefore it is the unit of Work or Energy.Energy = Power &#215;&#215; time = kilowatt - hour, in fact it is the commercial unit of Energy.

Electricity

Physics
8833 Views

What is the power produced by an appliance marked " $240 V$ , $2 A " ?$

A $24 V$ potential difference is applied across a parallel combination of four $6 Ω$ resistor. The current in each resistor is:

Electric current is to be passed from one body to another. For this purpose the two bodies must be joined by

The flow of the electric current through a metallic conductor is:

In a metallic conductor, electric current is thought to be due to the movement of:

An electric bulb works on $230 V$ line and draws $0.1 A$ current. The resistance of the filament is:

Which of the following option has no effect on an electric fuse wire?

Four identical wires each having resistance $R$ are connected as shown in the figure. Equivalent resistance between A and B is:

When we pay for our electricity bill, we are paying for the:

Which one of the following is not the unit of energy?

Electricity

Physics 8833 Views

What is the power produced by an appliance marked " 240V, 2A"?

A 24 V potential difference is applied across a parallel combination of four 6 Ω resistor. The current in each resistor is:

Electric current is to be passed from one body to another. For this purpose the two bodies must be joined by

The flow of the electric current through a metallic conductor is:

In a metallic conductor, electric current is thought to be due to the movement of:

An electric bulb works on 230 V line and draws 0.1 A current. The resistance of the filament is:

Which of the following option has no effect on an electric fuse wire?

Four identical wires each having resistance R are connected as shown in the figure. Equivalent resistance between A and B is:

When we pay for our electricity bill, we are paying for the:

Which one of the following is not the unit of energy?

Physics
8833 Views

What is the power produced by an appliance marked " $240 V$ , $2 A " ?$

A $24 V$ potential difference is applied across a parallel combination of four $6 Ω$ resistor. The current in each resistor is:

An electric bulb works on $230 V$ line and draws $0.1 A$ current. The resistance of the filament is:

Four identical wires each having resistance $R$ are connected as shown in the figure. Equivalent resistance between A and B is: