What is the unit of resistance?

If you connect three resistors having values $2 \, \Omega$, $3 \, \Omega$, and $5 \, \Omega$ in parallel, will the value of total resistance be less than $2 \, \Omega$, greater than $5 \, \Omega$, or lie between $2 \, \Omega$ and $5 \, \Omega$? Explain.

$A$ 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?

Given below is a circuit showing current flowing in it. Identify each component $A, B, C, D$ of this circuit.

$1 \; kWh = \ldots \ldots \; \text{joules}$

What type of electric charge does an electron possess?