// To find voltage reading and Error // Modern Electronic Instrumentation And Measurement Techniques // By Albert D. Helfrick, William D. Cooper // First Edition Second Impression, 2009 // Dorling Kindersly Pvt. Ltd. India // Example 4-5 in Page 62 clear; clc; close; // Given data // resistances in series R_1 = 100 * 10^3; R_2 = 50 *10^3; // sensitivity of two voltmeters S_1 = 1000; S_2 = 20000; V = 50; // range of the voltmeters E = 150; // voltage of battery in volt //Calculations //By voltage divider rule V_true = R_2 /(R_1+R_2)*E; printf("The true voltage across resistor R_2 = %d V\n",V_true); //Reading of the first voltmeter R_T1 = S_1 * V; // resistance of voltmeter = sensitivity * range R_p =(R_2 *R_T1)/(R_2 +R_T1)// effective parallel resistance R_c1 = R_1+R_p // The total circuit resistance V_1 = 25*10^3/R_c1 *E; printf("The reading of the first voltmeter = %d V\n",V_1); //Reading of the second voltmeter R_T2 = S_2 * V; // resistance of voltmeter = sensitivity * range R_p =(R_2 *R_T2)/(R_2 +R_T2) R_c2 = R_1 +R_p // The total circuit resistance V_2 = 47.6*10^3/R_c2 *E; printf("The reading of the second voltmeter = %0.2f V\n",V_2); %error_1 = (V_true - V_1)/V_true *100; printf("The error in the reading due to voltmeter 1 =%d%%\n",%error_1); %error_2 = (V_true - V_2)/V_true *100; printf("The error in the reading due to voltmeter 2 =%0.2f%%",%error_2); //Results // The true voltage across resistor R_2 = 50 V // The reading of the first voltmeter = 30 V // The reading of the second voltmeter = 48.37 V // The error in the reading due to voltmeter 1 =40% // The error in the reading due to voltmeter 2 =3.26% //The answers are varying as approximation is not done