Electric Circuits Answers

An emf of 5V is suddenly applied to an LR circuit. The value of the resistor in the circuit is 15 . At one inductive time constant, what is the rate at which energy is delivered by the battery?
1.05W
5.78W
120.42W
12.24W

7 The dielectric strength of polyethylene (i.e. the electric field value above which a spark will jump through the material) is
about
. The dielectric constant for polyethylene is 2.3. If polyethylene fills the gap between two metal plates 0.20 cm apart, how
large a voltage difference can be applied to the two plates before break down?
20 kV
36 kV
54 kV
60 kV


8 Two parallel plates of
each are given equal and opposite charges of
. The electric field within the dielectric material filling the space between the plates is
. Find dielectric constant of the material.
7.14
2.43
6.14
3.4

The presence of a depolarising field in a dielectric material placed in an external electric field the
capacitance of
the material?

The voltage current graph of a metallic conductor at two different temperatures t1 and t2 is shown below . At which temperature is the resistance higher ?

v=V[1-e^(-(t/T) ) ]
T is the time constant and is given by T = CR.
If C = 100nF, R = 47kΩ and V = 5V plot the charging curve over the range 0 to 20 ms.
From your graph estimate the rate of charging at 6ms.
Differentiate the charging equatiThe charging characteristic for a series capacitive circuit is:
v=V[1-e^(-(t/T) ) ]
T is the time constant and is given by T = CR.
If C = 100nF, R = 47kΩ and V = 5V plot the charging curve over the range 0 to 20 ms.
From your graph estimate the rate of charging at 6ms.
Differentiate the charging equation to find the rate of charging at 6 ms and compare this with your estimation. on to find the rate of charging at 6 ms and compare this with your estimation.