Observe the graph and answer any four questions from (a) to (e). V-I graph for a conductor is as shown in figure.
Question 1 (a)
(a) What do you infer from this graph?
(i) V ∝ 1/I
(ii) V ∝ I ^{ 2 }
(iii) V ∝ I
(iv) V ∝ 1/I ^{ 2 }
Answer:
The V-I graph is a straight line graph passing through the origin.
This implies that V is directly proportional to I.
So, the correct answer is (iii ).
Question 1 (b)
Name the physical quantity represented by the slope of this graph
(i) Current
(ii) Resistance
(iii) Potential difference
(iv) None of the above
Answer:
The slope of the V-I graph gives the resistance.
So, the correct answer is (ii).
Question 1 (c)
Ohm is the SI unit of:
(i) Potential difference
(ii) Resistance
(iii) Current
(iv) Resistivity
Answer:
The SI unit of resistance is ohm .
So, the correct answer is (ii).
Question 1 (d)
Which of the following law justify the above graph:
(i) Faradays Law
(ii) Ohm’s Law
(iii) Faradays Law
(iv) Joule’s Law
Answer:
Ohm’s law , states that the current passing through a conductor is directly proportional to the potential difference across its ends, provided the physical conditions like temperature, density etc. remain unchanged.
The V-I graph given above also states that current is directly proportional to potential difference.
So, the correct answer is (ii).
Question 1 (e)
Resistance of a conductor depends on:
(i) length of conductor
(ii) area of cross-section
(iii) temperature
(iv) all of the above
Answer:
Factors affecting resistance of a conductor are:
- Length of the conductor
- Area of cross section
- Nature of Material
- Temperature
Since all the factors are mentioned in the options.
So, the correct answer is (iv).