Name:

Muhammad Shahbaz Sharif

Student

Id: Bc160401593

Assignment

No. 3

PHY

(101)

Question

# 1

A video game console operates potential difference

of 12.00 V as shown in fig. The potential difference supplied by the power

receptacle is 120 V AC. A transformer is used to convert one voltage to the

other. If the secondary coil of the transformer (the 12.00 V side) has 1200

loops, how many loops does the primary coil have?

Solution:

Within a magnetic core magnetic flux occurs. The

flux dependent on primary current and primary turns Ip*Np. This same flux flows

in the core of secondary Is*Ns,

So Ip*Np= Is*Ns

Now on voltage, in accordance with lenz’s law, this

flux causes in each turn, an induced voltage. So the total include voltage is k*voltage/turn*turns*flux

Vs=kNs*flux

Or Vs/Ns=k*flux. But on the primary, the same

constant k is occurring in generating the flux, so

Vs/Ns=Vp/Np

Or VpVs=NpNs

120/12=1200/Ns

Or Ns=12000 turns.

Question # 2

a) Is it true or wrong to say that components in series must have the same

potential difference across them? Either yes or no explain it.

b) Is it true or wrong to say that magnetic

force vectors on charged particles point in the same direction as the magnetic

field? Either yes or no explain it.

c) What is the

electric potential at the location of the test charge in the figure shown below?

Solution:

a)

When two or more components are

connected in series, the potential difference of the supply is shared between

them. This mean that if you add together the voltage across each component

connected in series, the total equals the voltage of the power supply. Two

identical resistors connected in series will share the potential difference.

They will get half to each.

For example: If two identical resistors

are connected in series to 3V cell then the potential difference across each of

them is 1.5V.

b)

When a charged particle moved

through a magnetic field B, it feels a Force F given by cross product is F=qV*B

where is the electric charge of the particle is the magnetic field because this

is across product, the force is perpendicular to both the motion of the

particular and the magnetic field. It follows that the magnetic force does not

work on the particle it may change the direction of the particle movement, but

it cannot cause it to speed up or slow down.

c)

Clearly, the potential Function V

can be assigned to each point in the space surrounding a charge distribution.

The above formula provide the recipe to calculate the work done in moving a

charge between two points where we know that the value of the potential

differences.

The above statements and the

formula are valid regardless of the path through which the formulas are valid

regardless of the path through which the charged is moved. It can be found by

simple performance the integration through a simple path is chosen along a

radial line so that becomes simply. Since the electric field of Q is Kq/r2.

This process defines the electric potential of a point like charge. Note that

the potential function is a Scalar Quantity as oppose to electric field are

Vector Quantity.