Explanation:
The difference in potential between two points that represents the work involved or the energy released in the transfer of a unit quantity of electricity from one point to the other.
Explanation:
The unit of electrical resistance is ohm.
Explanation:
Current is measured in Coulomb/ sec or Ampere.
Explanation:
It is the SI unit of potential difference.
Explanation:
Watt is the unit of electric power.
Explanation:
A substance having infinitely high electrical resistance is called an insulator.
Explanation:
Joule is the SI unit of energy.
Explanation:
The resistivity of copper depends only on temperature.
Explanation:
The resistivity of a certain material is $0.6 Ω\ \text{m}. $The material is most likely to be a semiconductor because it has moderate resistivity.
Explanation: Resistivity of material does not depend on its dimensions and shape. However, resistivity depends upon the temperature and the nature of material.
Explanation:
Resistance, $\text{R}=\frac{\rho\text{I}}{\text{A}}$
Length, I = 300m
Cross section area, A = 1.0mm2 = 10-6 m2
Resistivity, $\rho=1.0\times10^{-7}\Omega\ \text{m}$
Resistance, $\text{R}=\frac{10^{-7}\times300}{10^{-6}}$
$\text{R}=30\Omega$
Explanation:
If the p.d. across a $3\Omega$ resistor is 6V, the current flowing in the resistor will be 2A as current (I) is given by the equation, $\text{I}=\frac{\text{V} (\text{Voltage})}{\text{R}(\text{Resistance})}.$
or $\text{I}=\frac{\text{V}}{\text{R}}$
$\text{I}=6\ \frac{\text{V}}{3}\ Ω$
$\text{I} = 2\text{A.}$
Explanation:
The term voltage came from volt, which is the SI unit of potential difference.
Explanation:
This is so because in a parallel circuit, if one device fails, it does not affect the working of the other devices.
Explanation:
This is so because heat, H = I2Rt.
Explanation:
We know that:
H = I2Rt
It shows that the heat produced is proportional to the square of the current.
Explanation:
Protons and neutrons are strongly bound to the atoms (in the nucleus).
Only electrons can be free from atoms.
The systematic flow of these free electrons constitutes a current.
Therefore, the electric current is only due to the flow of electrons.
Their combined resistance is:
Explanation:
The resistors of 6I and 2I are connected in parallel.
$\therefore\frac{1}{\text{R}}=\frac{1}{\text{R}_1}+\frac{1}{\text{R}_2}$ Here,
$\text{R}_1=6\Omega$
$\text{R}_2=2\Omega\ \frac{1}{\ \text{R}}=\frac{1}{6}+\frac{1}{2}\frac{1}{\text{R}}=\frac{4}{6}\ \text{R}=\frac{6}{4}$
This arrangement is further connected in series with the 6I resistor.
$\therefore$ Net resistance $=\frac{6}{4}+6=7\frac{1}{2}\Omega$
Explanation:
Nichrome has a high resistance.
Explanation:
The two resistors of 6I are connected in parallel with each other. So, their net resistance 3I is connected in series with a resistance of 6I. So, the net resistance of the complete arrangement is $9 Ω.$
Explanation:
A voltage meter is an instrument used for measuring the potential difference, or voltage, between two points in an electrical or electronic circuit.
Explanation:
The current flowing from positive terminal to negative terminal is due to flow of positive charge, which is the conventional current.
Explanation:
$\text{R} = 4\Omega$
$\text{V} = 10\text{V}$
$\text{I} = ?$
We know that
$\text{I} = \frac{\text{V}}{\text{R}}$
$\text{I} = \frac{10}{4}$
$\text{I} = 2.5 \text{A}$
Explanation:
Heat produced is directly proportional to the square of the current.
Explanation:
Assuming that each interval is of 1seconds, we can calculate the heat for each interval and just sum it up to find the net heat produced,
Heat, H = I2RT
Where,
I is the current,
R is the resistance,
T is the time taken
For AD,
$\text{I}=3, \text{R}=2\Omega,\text{T}=1\text{sec}$
Putting the values in the above formula, we get
$\text{H}_{\text{AD}}=3^{2}.2.1=18\text{J}$
For DG,
$\text{I}=-2\text{A},\text{R}=2\Omega,\text{T}=1\text{sec}$
Putting the values in the above formula, we get
$\text{H}_{\text{DG}}=3^{2}.2.1=18\text{J}$
For GJ,
$\text{I}=-2\text{A},\text{R}=2\Omega,\text{T}=1\text{sec}$
Putting the values in the above equation, we get
$\text{H}_{\text{GJ}}=1^{2}.2.1=2\text{J}$
So Total amount of heat generated in 3sec
$\text{H}_{\text{NET}}=18+8+2=28\text{J}$
Explanation:
Kilowatt-hour is the commercial unit of electrical energy.
Explanation:
An ammeter is connected in series in a circuit and voltmeter is connected in parallel.
Explanation:
Cotton is an insulator, rest are good conductors.
Explanation:
SI unit of electrical energy is Joule.
1 Joule = 1 Volt × 1 ampere × 1 second.
Explanation:
The interaction between two like-charged objects isrepulsive. The interaction between two oppositely charged objects is attractive.
Explanation:
One kilowatt-hour is equal to 3.6·106 joules:
Explanation:
The coulomb is the SI unit of electric charge. It is the charge transported by a constant current of one ampere in one second. It is equivalent to the charge of approximately 6.25 × 1018 protons or electrons.
Explanation:
Ohm's law gives the relationship between current and potential difference.
Explanation:
Copper is a good conductor of electricity as it allows the electricity to flow through it easily.
Copper as a connecting wire has very low electrical resistance.
Copper combines several properties that have traditionally made it preferred for most electrical wiring.
It provides good contact surface, is ductile (is easily bent repeatedly without breaking) and it is not very expensive and is easy to manufacture.
Explanation:
As we know from Ohm’s law:
Voltage = Current × Resistance
V = IR
If the voltage is constant, the resistance is doubled and the current becomes half.
Explanation:
As we know from Ohm’s law:
Voltage = Current × Resistance
V = IR
If the voltage is constant, the resistance of the circuit is halved. That is, it becomes $\frac{\text{R}}{2}$
Current, $\text{I}=\frac{\text{V}}{\text{R}}$
$\text{I}=\frac{\text{V}}{\text{R}}$
$\text{I}=\frac{\frac{\text{V}}{\text{R}}}{2}=2\text{I}$
Thus by keeping the p.d. constant, the resistance of a circuit is halved and the current is doubled.
Explanation: In this case, two resistors are in series. Hence, their sum will be equal to their arithmetic sum. In figure (iii) the total resistance will be less than individual resistances because they are connected in parallel. A higher resistance produces more heat so option (c) is correct.
Explanation:
The resistors of $1 Ω, 2 Ω$ and $3 Ω$ are connected in series. Therefore, the net resistance,
$\text{R} = \text{R}_1 + \text{R}_2 +\text{R}_3$
$\text{R}=1\Omega+2\Omega+3\Omega=6\Omega$
Current in the circuit will be,
$\text{I}=\frac{\text{V}}{\text{R}}$
or $\text{I}=\frac{2}{6}=\frac{1}{3}\text{A}$
Current $=\frac{1}{3}\text{A}$
Therefore, the voltage across the 3I resistor,
V = IR
or $\text{V}=\frac{1}{3}\times3=1\text{V}$
Explanation:
Insulators have tightly bound electrons which cannot move freely and hence cannot conduct electricity.
Explanation: Total resistance of combination
$2\Omega+4\Omega=6\Omega$Current through the circuit can be calculated as
$\text{I}=\frac{\text{V}}{\text{R}}=\frac{6\text{V}}{6\Omega}=1\text{A}$Heat dissipation by can be calculated as follows:
$\text{H}=\text{I}^2\text{Rt}=(1\text{A})^2\times4\Omega\times5\text{s}=20\text{J}$