Time rate of work done or electrical energy developed or consumed by a generator or appliance, is called electrical
Electric power is the rate, per unit time, at which electrical energy is transferred by an electric circuit. The SI unit of power is the watt.
The power of the battery in the resistor appears as
Firstly, you get shorter battery life simply because your average energy consumption is increased over the peak period.A battery generates power when it powers a light bulb. It dissipates power when it is being charged.
In series combination of electrical appliances, total electrical power
Power is directly proportional to the potential difference and potential difference is directly proportional to the Current. In a series combination, Resistance is increased and thus the flow of current decreases Power is directly proportional to current therefore power decreases.
The rate of flow of an electric charge is known as :
As more and more resistors are added in parallel to a circuit, the equivalent resistance of the circuit decreases and the total current of the circuit increases.Therefore the power decreases.
Power voltage rating of an electric bulb is 100 W 200 V. Current drawn by it will be
current = 100/200
The total work done by an electrical appliance during its operation, is called electrical
The unit of electrical energy is
Joule is the unit of work or energy; it is equal to the work done by a force of one newton acting through one meter. It was named in honor of the English physicist James Prescott Joule. It equals 107 ergs, or approximately 0.7377 foot-pounds. In electrical terms, the joule equals one watt-second—i.e., the energy released in one second by a current of one ampere through a resistance of one ohm.
Number of joules in 1 kWh is
When electric current flows through a conductor the conductor becomes
When electric current flows through a conductor
Heating of a current carrying conductor is due to
An electric current is passing through a conductor which becomes hot after some time and produces heat. This is due to the conversion of some of the electrical energy that passes through the conductor, into heat energy. This effect of electric current is called the heating effect of current.
Out of the following which is an insulating material ?
Rate of energy transferred if a current of 0.5 A passes through a bulb connected across a battery of 6 V for 20 s is
Energy = v × i × t = 6 × 0.5 × 20 = 60J
In electric heating appliances the material of the heating element is
In domestic electric circuits, the cheapest appliance used is
A fuse is used to break the circuit,in order to protect the electrical appliances from damage. In case of overcurrent a fuse melts and breaks the circuit and stops the current flowing through the components. A fuse is made up of a thin material which has a low melting point.
An ammeter has 20 divisions between mark 0 and mark 2 on its scale. The least count of the ammeter is
20 Divisions are equal to the 2A
1 division is equal to 2/20 = 0.1 A
therefore Least count of the Ammeter is 0.1 A.
In a voltmeter, there are 20 divisions between the 0 mark and 0.5 V mark. The least count of the voltmeter is
Least count= 0.5/20
Which two circuit components are connected in parallel in the following circuit diagram ?
A voltmeter measures a difference in potential, voltage. It compares the voltage on one probe with the voltage on the other and gives the difference. Because they are commented in parallel, they must have a high resistance, so as not yo effect operation of the circuit.
Resistance of a wire is r ohms. The wire is stretched to double its length, then its resistance in ohms is
Resistance ‘R = 6ohm’ is related to length ‘L’, area of cross-section ‘A’ and resistivity ‘ρ’ as,
R = ρL/A
When L is doubled ,
As we know that the volume of the wire remains same.
old volume = new volume
AL = A'L' ....(i) ( as volume = area x length )
L' = 2L
So, from (i)
A' = A/2
So the new resistance is ,
R' = ρL'/A'
R' = ρ(2L)/(A/2) = 4 (ρL/A)
=> R' = 4R
thus, correct answer is option (b).
Electric pressure is also called
Substances whose atoms have no free electrons, are called
Substances whose atoms have only few free electrons, are called
A neutral body has
An electrically neutral object is an object that has a balance of protons and electrons. In contrast, a charged object has an imbalance of protons and electrons. The type of charge (positive or negative) is determined by whether the protons or the electrons are in excess.
A body gets positively charged by losing
A body gets negatively charged by gaining
Electrons have negative energy. When the number of electrons and protons are equal the charge is neutral but if electron is added to it then the negative charge dominates which gives it negative charge.