1. The problem statement, all variables and given/known data A voltmeter reads 8V at full scale deflection, and is graded according to its resistance per volt at full scale deflection as 5000 ohms / volt. How will you convert it into a voltmeter that reads 20V at full scale deflection? Will it still be graded as 5000 ohms / volt.? Will you prefer this voltmeter to one that is graded ats 2000 ohms /volt? 2. Relevant equations Application of Ohm's Law 3. The attempt at a solution Let R = voltmeter resistance I = current through voltmeter for full scale deflection If the voltmeter has to read 20V at full scale deflection, we need an additional resistance r in series with it. Thus 8/R = 20/R+r R = 5000 *8 (since the voltmeter is graded as 5000 ohms/V for full scale deflection of 8V) 1/5000 = 20/40000 +r r= 60000 ohms The above has been calculated using the voltmeter grading as 5000 ohms /V. I need some clues to proceed further with the next part of the question as I am not sure as to whether my way of looking at the voltmeter grading is correct or not.