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3. A student carries out an experiment and plots the V-I graph of three samples
of nichrome wire with resistances R 1 R 2 and R 3 respectively. Which of the
following is hue? [NCERT Exemplar Problems]

(a) R 1 = R 2 = R 3
(b) R 1 > R 2 > R 3
(c) R 3 > R 2 > R 1
(d) R 2 > R 3 > R 1
4. Assertion: The statement of Ohm’s law is K = IR
Reason: V = IR is the equation which defines resistance.

According to ……… Law, the potential difference across the ends of a resistor is
directly proportional to the ……… through it, provided its remains constant.

Subjective Questions
The resistance of an electric iron is 50Ω and 3.2A Current flows through the
resistance. Find the voltage between two points.
1. An EMF source of 8.0 V is connected to a purely resistive electrical appliance
(a light bulb). An electric current of 2.0 A flows through it. Consider the
conducting wires to be resistance-free. Calculate the resistance offered by the
electrical appliance.
2. What is ohm? Define it.
3. A resistance of 1 k Ω has a current of 0.25 A throughout it when it is
connected to the terminals of a battery. What is the potential difference across
the ends of a resistor.
4. A lamp draws a current of 0.5 A when it is connected to a 60 V source. What
is the resistance of the lamp?
5. A torch bulb is rated at 1.5 V, 500 mA. Find its resistance.

Name: Admission No: Class/Sec: (
) DT:_________________

VERIFICATION OF OHM’S LAW

Aim

To study the dependence of potential difference (V) across a resistor on the current
(/) passing through it and determine its resistance. Also plot a graph between V and
I.