For power dissipation in parallel circuits:
• Power is inversely proportional to resistance in parallel arrangements.
• Compare power ratios directly using \(P ∝ 1/R\).
- The power dissipated in a resistor is:
\[ P = \frac{V^2}{R}. \]- For \( R \): \( P_1 \propto \frac{1}{R} \), and for \( 3R \): \( P_2 \propto \frac{1}{3R} \).
- The ratio of powers:
\[ \frac{P_1}{P_2} = \frac{3R}{R} = 3 : 1. \]Find output voltage in the given circuit. 

In the given figure, the blocks $A$, $B$ and $C$ weigh $4\,\text{kg}$, $6\,\text{kg}$ and $8\,\text{kg}$ respectively. The coefficient of sliding friction between any two surfaces is $0.5$. The force $\vec{F}$ required to slide the block $C$ with constant speed is ___ N.
(Given: $g = 10\,\text{m s}^{-2}$) 
Two circular discs of radius \(10\) cm each are joined at their centres by a rod, as shown in the figure. The length of the rod is \(30\) cm and its mass is \(600\) g. The mass of each disc is also \(600\) g. If the applied torque between the two discs is \(43\times10^{-7}\) dyne·cm, then the angular acceleration of the system about the given axis \(AB\) is ________ rad s\(^{-2}\).
