In our daily life,we use two types of electric current whose current-time graphs are given below:
$(i)$ Name the type of current in two cases.
$(ii)$ Identify any one source for each type of current.
$(iii)$ What is the frequency of current in case $(b)$ in our country?
$(iv)$ On the basis of these graphs,list two differences between the two currents.
$(v)$ Out of the two,which one is used in transmitting electric power over long distances and why?

(N/A) $(i)$ $(a)$ Direct current $(DC)$
$(b)$ Alternating current $(AC)$
$(ii)$ Source of direct current: Battery or cell. Source of alternating current: $AC$ generator or power plant.
$(iii)$ The frequency of $AC$ in our country is $50 \, Hz$.
$(iv)$ Two differences between the two currents are:
$1$. The magnitude of $DC$ remains constant with time,whereas the magnitude of $AC$ changes continuously with time.
$2$. The direction of $DC$ remains fixed,whereas the direction of $AC$ reverses periodically.
$(v)$ Alternating current $(AC)$ is used for transmitting electric power over long distances because it can be stepped up or down using transformers,which significantly reduces energy loss during transmission compared to $DC$.