Assignment 3: (Spring 2014)
TOTAL MARKS: 30
Due Date: 10/07/2014
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Q no 1:
using Ohms law
otherwise : the solution is like this
watts to amps conversion:
now use this =
check it according to handouts !!
because the resistance at any position has a constant value , but if u affect it by heat or you changed the material of it or change its long or cross sectional area , then it will change according to this relation R=p *(L/A)
where R is the resistance
p is the specific resistance (depends on the material of the resistor)
L is the resistors long
A is the cross sectional area of the resistor
Current "splits" at principle nodes
remains same at resistors
Voltage drops at resistors
Q no 4 hint :
Suppose that a negatively charged rubber balloon is brought near a single sphere as shown below (Diagram ii). The presence of the negative charge will induce electron movement in the sphere. Since like charges repel, negative electrons within the metal sphere will be repelled by the negatively charged balloon. There will be a mass migration of electrons from the left side of the sphere to the right side of the sphere causing charge within the sphere to become polarized (Diagram ii). Once charge within the sphere has become polarized, the sphere is touched. The touching of the sphere allows electrons to exit the sphere and move through the hand to "the ground" (Diagram iii). It is at this point that the sphere acquires a charge. With electrons having left the sphere, the sphere acquires a positive charge (Diagram iv). Once the balloon is moved away from the sphere, the excess positive charge redistributes itself (by the movement of remaining electrons) such that the positive charge is uniformly distributed about the sphere's surface.
Q no 5 hint :
How much energy is released when the capacitor is discharged?
Energy stored= 1/2 C*V^2 = 1/2 (20E-6)(4000^2 = 160 J
c. If the capacitor completely discharges in 2.0 ms, what is the average current
delivered by the defibrillator?
I = Q/t = .08/.002 = 40 A
for Q no 5 u will use formula
where Q = C*V
Hope its helpful now !!
r u get full solution?????????
e) The balloon will cause a polarization of charge in the sphere
There is negative charge on balloon due to extra electron deposited on it whenever a neutral body i.e. a metal sphere in this case is brought near to it then it will begin to polarization(division) of charge because it is the nature of an object to tends to be neutral.
full solution do yar
koi to solution upload kro plzzzzzzzzz
Question no 2
This is wrong statement because when current passes through the resistors it gets hot and its resistance increases
See page 74 lec 26 for example