# Current Electricity-Electrical Resistance (KVPY Stream-SA (Class 11) Physics): Questions 1 - 2 of 2

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## Question number: 1

» Current Electricity » Electrical Resistance

### Write in Short

Consider the two circuits P and Q, shown below, which are used 20 measure the unknown resistance R.

In each case, the resistance is estimated by using Ohm’s law , Where V and I are the readings of the voltmeters and the ammeters respectively. The internal resistances of voltmeter and ammeter are R _{V} and R _{A}, such that R _{A} < < R < < R _{V}.

The internal resistance of the battery may be ignored. The absolute error in the estimate of the resistance is denoted by δ R =| R - Rest| .

(a) Express δ R _{P} in terms of the given resistance values

(b) Express δ R _{Q} in terms of the given resistance values

(c) For what value of R will δ R _{P } ≈ δ R _{Q}

## Question number: 2

» Current Electricity » Electrical Resistance

Appeared in Year: 2011

### Question

A cylindrical copper rod has length L and resistance R. If it is melted and formed into another rod of length 2L, than the resistance will be

### Choices

Choice (4) | Response | |
---|---|---|

a. | 8R | |

b. | R | |

c. | 4R | |

d. | 2R |