Question

20. Read the following and answer any four questions from 19(b) to 19(v).
The current in the conductor is directly proportional to the potential difference across the conductor
provided physical conditions of the conductor i.e., temperature, length, cross-sectional area and
material, does not change.
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Putting the proportionality constant (R), we get i = V/R or V - iR, where R is a constant called
resistance of conductor
Substance which follow Ohm's law are called ohmic substance or a linear conductor. For ohmio
substances, the slope of i versus V graph is a constant. Substances which do not follow Ohm's
law are called non-ohmic substance or non-linear conductor. For non-ohmic substances, the slope
of i versus V graph is not a constant. A student wants to check experimentally how the resistance
of a lamp varies with the length of the wire. Two sets of reading obtained, are shown below.
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Ammeter reading, I (A) Voltmeter, V(V) Resistance, R(Q)
0.2
0.4
1.0
3.2
(1) Using the table calculate the resistance of the lamp for different currents.
(a) 1,2
(b) 2.0.3.2
(c) 4.2, 5.1
(d) 2.2, 2.8
(in) Before the current flows in the lamp, what is the reading on the voltmeter?
(a) 0 V
(b) 0.4 V
(c) 3.2 V
(d) 0.6 V
(ii) Which of the following I-V graph represents for ohmic conductors?
IA
(c)
(b)
r
(d)
V
(iv) The electrical resistance of a conductor depends upon
(a) size of conductor
(b) temperature of conductor
(c) geometry of conductor (d) all of these
(v) Slope V-I graph gives
(a) resistivity (b) energy dissipated (c) power
(d) resistance
STION​

Answer 1

Answer:

According to Ohm's law, the electric current flowing through a conductor is directly proportional to the potential difference across the ends of a conductor provided temperature and other physical conditions remain same.