The $V -I$ graph for series and parallel combination of two metallic resistors is as shown in the figure. Which graph represents parallel combination? Justify your answer.
Slope of $V-I$ graph is equal to the resistance of the combination. It is less for graph $A ,$ which means less resistance. In parallel combination, resistance becomes less.
State reasons for the following
$(a)$ Tungsten is used for making bulb filaments.
$(b)$ Copper and aluminium are generally used for electricity transmission.
$(c)$ Alloys are commonly used in electrical heating devices such as electric iron and toaster.
State $Ohm's$ law. How can it be verified ?
When do we say that the resistors are connected in series ?
A bulb gets dimmer for a moment when a geyser, connected across the same source is switched on. Why ?
What is meant by $1$ ohm resistance ?