2021-MJ-51
Defining the problem:
 T is the dependent variable and R is the independent
variable.
 L, A and N of the coil must be kept constant
throughout the experiment.
Method of Data Collection:
 Using a separate Circuit to measure R. The circuit
consists of a voltmeter, ammeter, resistor that is to
be measured) DC battery with known emf.
 R calculated using the formula R=V/I
 Length of coil L can be measured using a meter rule.
 The diameter of the coil is measured using a Vernier
caliper and the reading is taken along the length of
the coil and the average value is used to calculate
Area, A using the formula πd2/4.
 The number of turns N is just counted
 Using a CRO time t is measure. From the CRO screen
the boxes are counted and it is multiplied with the
time base settings.
Data Analysis:
 t=
𝐾𝑁2 𝐴
𝐿
×
1
𝑅
 Plot a graph where t is on Y-axis and 1/R is on X-axis
and KN2A/L is the gradient.
 Using gradient K is calculated using formula
Safety Precaution:
 Wear insulated gloves to present getting
electrocuted
Additional Details:
 Using crocodile clips to ensure good connections
 Experiment is repeated by changing R and taking the
average time t.
 Switch is opened before changing R
 Switch is also opened after taking the reading to
prevent components getting heated.
 To get a measurable time to reduce uncertainty Coil
with more turns and greater surface area is used.
 The graph plotted should be a straight line passing
through the origin.