
Given the following resistor network, the resistances are arranged as shown:
From the given circuit:
The resistances between points A, B, C, and D are:
\( 6 \, \Omega \) between A and C, \( 10 \, \Omega \) between B and C, \( 8 \, \Omega \) between C and D, \( 5 \, \Omega \) between B and D, and \( 4 \, \Omega \) between A and D.
First, combine the resistances in parallel and series:
Combine the \( 15 \, \Omega \) resistors in series between points A, C, and B. After the simplification, we get:
\( R_{\text{eq}} = 6 \, \Omega + 5 \, \Omega + 8 \, \Omega = 19 \, \Omega \)
Thus, the correct answer is:
\( R_{\text{eq}} = 19 \, \Omega \)

Thus the correct answer is 19 $\Omega$.
The equivalent resistance between the points \(A\) and \(B\) in the given circuit is \[ \frac{x}{5}\,\Omega. \] Find the value of \(x\). 
A Wheatstone bridge is initially at room temperature and all arms of the bridge have same value of resistances \[ (R_1=R_2=R_3=R_4). \] When \(R_3\) resistance is heated, its resistance value increases by \(10%\). The potential difference \((V_a-V_b)\) after \(R_3\) is heated is _______ V. 
The heat generated in 1 minute between points A and B in the given circuit, when a battery of 9 V with internal resistance of 1 \(\Omega\) is connected across these points is ______ J. 
The following diagram shows a Zener diode as a voltage regulator. The Zener diode is rated at \(V_z = 5\) V and the desired current in load is 5 mA. The unregulated voltage source can supply up to 25 V. Considering the Zener diode can withstand four times of the load current, the value of resistor \(R_s\) (shown in circuit) should be_______ \(\Omega\).
Method used for separation of mixture of products (B and C) obtained in the following reaction is: 