Question

Match the entries in column A with appropriate ones from column B.

Answer 1

• The electrical potential or voltage (V) between two points is defined to be the work (W) done by the electric force in transporting a unit of positive charge (Q) from one point to another.
  

• The SI unit joule is too small to express very large quantities of energy. Hence we use a bigger unit called kilowatt-hour (kWh) to express energy. 1 kWh is the amount of energy consumed by an electrical gadget in one hour at the rate of 1000 J/s or 1kW.
• Resistance of a wire is directly proportional to the length of the wire and inversely proportional to the cross-section of the wire. The constant of proportion is called resistivity.
• Superconductor has zero resistance.
• The resistance R in ohms is equal to the voltage V in volts (V) divided by the current I in amps (A). 1-ohm resistance means, transmitting a current of one ampere when subjected to a potential difference of one volt.
• Transistor is an example of non-ohmic conductor. A transistor, made up of semiconductors, does not follow ohm's law.
• Resistance $R=\rho \frac{L}{A}$ where $\rho$ resistivity

$\rho =R\frac{A}{L}$

So its unit comes as ohm-meter.

• When cells are connected in series, their EMFs add up to indicate the total EMF of the circuit. ie $E=E_1+E_2$

• According to Joule law of heating, $Q=i^{2}Rt$

• Neutral wire is there is no current flow ie $i=0$.