The equivalent resistance of two identical resistors in parallel is 10 Ω. The equivalent resistance of the same resistors in series would be

Let $R$ be the resistance of each identical resistor. For two identical resistors in parallel, the equivalent resistance $R_{eq,p}$ is given by:

We are given $R_{eq,p} = 10 \Omega$.

For resistors in series, the equivalent resistance $R_{eq,s}$ is the sum of individual resistances:

The correct option is C.

The capacitance in air is $C_{air} = 20 \mu\text{F}$.
The capacitance with the dielectric is $C_{dielectric} = 42 \mu\text{F}$.

The dielectric constant $\kappa$ is defined as the ratio of the capacitance with the dielectric to the capacitance in air:

The correct option is C.

We are given the charge $q = 2.0 \text{ C}$ and the potential difference $V = 12 \text{ V}$.
The work done $W$ in moving a charge $q$ against a potential difference $V$ is given by:

The correct option is C.

We are given the resistance $R = 50 \Omega$ and the current $I = 2 \text{ A}$.
The power $P$ dissipated as heat in a resistor is given by:

The correct option is C.