$1 \text{ kWh} = 3.6 \times 10^6 \text{ joules}$. Is this statement true or false?

$(a)$ What is meant by saying that the potential difference between two points is $1$ volt?
$(b)$ Why does the connecting cord of an electrical heater not glow while the heating element does?
$(c)$ Electrical resistivities of some substances at $20^{\circ}C$ are given below:

Silver	$1.60 \times 10^{-8} \, \Omega m$
Copper	$1.62 \times 10^{-8} \, \Omega m$
Tungsten	$5.2 \times 10^{-8} \, \Omega m$
Iron	$10.0 \times 10^{-8} \, \Omega m$
Mercury	$94.0 \times 10^{-8} \, \Omega m$
Nichrome	$100 \times 10^{-6} \, \Omega m$

Answer the following questions in relation to them:
$(i)$ Among silver and copper, which one is a better conductor? Why?
$(ii)$ Which material would you advise to use in electrical heating devices? Why?

$A$ heater is joined in parallel with a $60\, W$ bulb and connected to the mains. If the $60\, W$ bulb is replaced by a $100\, W$ bulb,will the rate of heat produced by the heater be more,less,or remain the same?

No current flows between two charged bodies when connected,if they have the same

Which of the following is the symbol for a resistor?

Which effect of electric current is used in electroplating?