//Example 5.4 // potential difference across the heater element clc; clear; close; w=20;// in kg t1=10;// in degree celsius t2=90;//in degree celsius t=2*3600+19*60+34;// time in seconds I=4;// in ampere n=80;//efficiency of conversion in percentage ho=w*(t2-t1);//output heat required in kcal V=((ho*4187*100)/(I*t*n));// POTENTIAL DROP IN VOLTS disp(V,"potential drop across heater element in volts is")