In an experiment to determine the resistance of a given wire using Ohm's law, the voltmeter and ammeter readings are noted as 10 V and 5 A, respectively. The least counts of voltmeter and ammeter are 500 mV and 200 mA, respectively. The estimated error in the resistance measurement is .
- 0.25
- 2
- 2.5
- 0.18
Answer
(4) 0.18
Solution
R= VI= 105=2
Errors (least counts): V=500 mV=0.5 V, I=200 mA=0.2 A
For a quotient: RR= VV+ II
RR= 0.510+ 0.25=0.05+0.04=0.09
R=0.09 2=0.18
Answer: (4)