Electricity 1

Question 1

what is electricity?

Answer 1

electricity is a source/form of energy which is due to the flow of charge.

Question 2

give the formula for the flow of charges.

Answer 2

Q= n x e
where Q is the net charge
n is number of electrons
e is charge of one electron

Question 3

what is the charge of 1 electron

Answer 3

1 electron possesses a negative charge of 1.6 × 10⁻¹⁹ C.)

Question 4

how much is one coulomb equal to?

Answer 4

1 coulomb refers to the charge contained in 6 x 10¹⁸

Question 5

define electric current

Answer 5

Electric current refers to the flow of charge. Electric current is expressed by
the amount of charge flowing through a particular area in unit time.

Question 5

how do we express electric curren

Answer 5

I=Q/t
where I refers to current
Q refers to the net charge
t-refers to the time

Question 5

define 1 ampere

Answer 5

When 1 coulomb of charges flows through the cross section of a conductor in 1 second, then the current is said to be 1 ampere

1 A = 1 C/1 s.

Question 6

list some other units for ampere

Answer 6

Small quantities of current are expressed in milliampere
(1 mA = 10⁻³ A) or in microampere (1 µA = 10⁻⁶ A).

Question 7

explain convential and electron flow of charges

Answer 7

electrons
were not known at the time when the phenomenon of electricity was first
observed. So, electric current was considered to be the flow of positive
charges and the direction of flow of positive charges was taken to be the
direction of electric current. Conventionally, in an electric circuit the
direction of electric current is taken as opposite to the direction of the
flow of electrons, which are negative charges.

Question 8

what instrument is used to measure current?

Answer 8

The instrument used ot measure resistance is called AMMETER. It has 0 resistance.It is always connected in series
in a circuit through which the current is to be
measured.

Question 9

What is potential difference or voltage?

Answer 9

The potential difference between two points in an electric field is defined as the amount of work done to move a unit positive charge from one point to another.

Question 10

how can we express voltage?

Answer 10

V= W/Q
where V- voltage is volts
W- work done in joules
Q-charge in coulombs

Question 11

define 1 volt

Answer 11

One volt is the potential difference between two points in a current-carrying conductor when 1 joule of work is done to move a charge of 1 coulomb from one point to the other.
1V= 1J/1C

Question 12

What is voltmeter

Answer 12

Voltmeter is an instrument used to measure potential difference. It is a high resistance device. It’s resistance is infinity. The voltmeter is always connected in parallel across the points between which the potential difference is to be measured.

Question 13

describe the role of a battery or cell in circuit?

Answer 13

The potential difference is produced and maintained by a cell or a battery which consisting of more than one cell. The chemical action within
a cell generates the potential difference across the terminals of the cell,
even when no current is drawn from it. When the cell is connected to a
conducting circuit element, the potential difference sets the charges in
motion in the conductor and produces an electric current. In order to
maintain the current in a given electric circuit, the cell has to expend its
chemical energy stored in it.

Question 14

define electric circuit? what is an open electric cirucuit and closed one?

Answer 14

electric circuit is a closed conducting path of current which contains a source providing potential difference and a device using the electrical energy.
open electric circuit: an electric circuit through which no current is flowing
closed electric circuit: an electric circuit through which current is flowing continouously.

open
->not closed and continous
->no current flows through the circuit
-> key is represented as ( )

closed
->it is closed and continous
->current flows through circuit
-> key is represented (.)