Explain the terms potential and potential difference. Give their $SI$ units.
Potential : Potential at a point is defined as the amount of work done in moving a unit charge form infinity to that point.
Potential difference : Potential difference between two points is defined as the amount of work done in moving a unit charge between the two points.
Both potential and potential difference are measured in volt.
There is a frill of $20$ bulbs connected in series in a room. One bulb gets fused. The remaining $19$ are again joined in series and connected to the same supply. Will the light increase or decrease in the room ?
Calculate the equivalent resistance in the combination shown in figure below
Which of the following represents Ohm's law?
Find the resistance of bulb rated as $100\, W -250 \,V$.
$(a)$ Name an instrument that measures potential difference between two points in a circuit. Define the unit of potential difference in terms of SI unit of charge and work. Draw the circuit symbols for $(i)$ variable resistor, $(ii)$ a plug key which is closed one.
$(b)$ Two electric circuits $I$ and $II$ are shown below
$(i)$ Which of the two circuits has more resistance ?
$(ii)$ Through which circuit more current passes ?
$(iii)$ In which circuit, the potential difference across each resistor is equal ?
$(iv)$ If $R_{1}>R_{2}>R_{3}$, in which circuit more heat will be produced in $R_{1}$ as compared to other two resistors ?