A voltmeter of resistance 1000Ω.0.5V / div is to be converted into a voltmeter to make it to read =1V∕div. The value of high resistance to be connected in series with it is
To convert a voltmeter of resistance 1000Ω with a sensitivity of 0.5V∕ div into a voltmeter with a sensitivity of 1V∕ div, we need to connect an additional high resistance in series with the voltmeter. The original voltmeter reads 0.5V∕ div which means for every 0.5 V , the internal resistance is 1000Ω. To make it read 1V∕ div, we effectively need to double the voltage range it can measure for the same current passing through the meter. Let the required high resistance to be connected in series be Rs. The total resistance of the voltmeter circuit for 1V∕div would then be given by: Rtotal =Rv+Rs Given the original voltmeter resistance (Rv) is 1000Ω and considering we need to double the effective voltage being measured, the total resistance should also be doubled: Rtotal =2×Rv Substituting Rv :
2×1000Ω=2000Ω This gives the equation: Rtotal =1000Ω+Rs=2000Ω Solving for Rs : Rs=2000Ω−1000Ω=1000Ω Thus, the value of the high resistance to be connected in series with it is: Option D: 1000Ω