Electricity: Class 10 Science Q&A · Page 6
281 free answers on Electricity (Science) for Class 10 students, across CBSE, ICSE and State boards.
Question & Answer
Questions
- ScienceClass 10ICSE
Define watt-hour. How many joules are equal to 1 watt-hour?
Watt-hour is defined as the amount of electrical energy that is consumed when an electrical appliance of 1 watt power is used for 1 hour. 1 watt-hour = 3600 joules.
- ScienceClass 10ICSE
Define watt. Write down an equation linking watts, volts, and ampere.
Following is the equation that relates watts, volts, and ampere: 1 watt = 1 volt × 1 ampere
- ScienceClass 10ICSE
What current will be taken by a 920W appliance if the supply voltage is 230V?
Given, P = 920W V = 230V I = ? We know that, P = VI 920 = 230I I = 920/230 I = 4A
- ScienceClass 10ICSE
An electric lamp is labelled 12V, 36W. This indicates that it should be used with a 12V supply. What other information does the label provide?
The other information provided by the label is that the rate of consumption of energy takes place at 36J/s.
- ScienceClass 10ICSE
. If the potential difference between the end of a wire of fixed resistance is doubled, by how much does the electric power increase?
We know that, P =V2/R R is constant V is doubled Therefore, P = 2(V2)/R P = 4V/R Therefore, when the resistance is doubled, power becomes four times the actual value.
- ScienceClass 10ICSE
What is the meaning of the symbol kWh? Which quantity does it represent?
kWh is the commercial unit of electrical energy and it stands for kilowatt-hour.
- ScienceClass 10ICSE
Which quantity has the unit of watt?
Watt is the unit of electric power.
- ScienceClass 10ICSE
Name the quantity whose unit is kilowatt and kilowatt-hour.
Kilowatt is the unit of electric power and kilowatt-hour is the unit of electric energy.
- ScienceClass 10ICSE
What is the SI unit of electric energy and electric power?
The SI unit of electric energy is joule and the SI unit of electric power is watt.
- ScienceClass 10ICSE
An electric bulb is rated at 220V, 100W. What is its resistance?
Given, V = 220V P = 100W R = ? We know that, R = V2/P R = 484 ohm
- ScienceClass 10ICSE
Name the commercial unit of electric energy.
The commercial unit of electric energy is kilowatt-hour.
- ScienceClass 10ICSE
Which one has a higher electrical resistance: a 100 watt bulb or a 60 watt bulb?
60 watt bulb has a higher electrical resistance than a 100 watt bulb because we know that power is inversely proportional to the resistance.
- ScienceClass 10ICSE
State two factors on which the electrical energy consumed by an electrical appliance depends. Answer:
Following are the two factors on which the electrical energy consumed by an electrical appliance depends: Usage time of the appliance Power rating of the appliance
- ScienceClass 10ICSE
If current flows through two lamps arranged in: a) series b) parallel and the filament of one lamp breaks, what happens to the other lamp? Explain
When the lamps are arranged in series, the lamps stop glowing when the filament of one of the lamps When the lamps are arranged in parallel, the lamps continue to glow even if one of the lamps
- ScienceClass 10ICSE
How do you think the brightness of two lamps arranged in parallel compares with the brightness of two lamps arranged in series?
When the two lamps are arranged in parallel, the lamps will have more brightness than when they are arranged in series.
- ScienceClass 10ICSE
If you were going to connect two light bulbs to one battery, would you use a series or a parallel arrangement? Why? Which arrangement takes more current from the battery?
When the arrangement is in parallel the consumption of current from the battery is more. The defect in any of the bulb won’t affect the working of the other bulbs.
- ScienceClass 10ICSE
Ten bulbs are connected in a series circuit to a power supply line. Ten identical bulbs are connected in a: a) an identical power supply line b) which circuit would have the highest voltage across each bulb? c) in which circuit would the bulbs be brighter? d) in which circuit, if one bulb blows out, all others will stop glowing? which circuit would have less current in it?
To have an identical power supply line, the circuit must be parallel When the circuit is parallel, each bulb will have highest voltage The working of the appliance can be controlled using individual switch when a parallel circuit is used The working of the appliances are not dependent on each other when they are connected in parallel
- ScienceClass 10ICSE
Given three reasons why different electrical appliances in a domestic circuit are connected in parallel.
Different electrical appliances in a domestic circuit are connected in parallel because: the voltage distribution to each appliance is the same from the power supply line the working of the appliance can be controlled using individual switch the working of the appliances are not dependent on each other
- ScienceClass 10ICSE
Why is a series arrangement not used for connecting domestic electrical appliances in a circuit?
A series arrangement is not used for connecting domestic electrical appliances in a circuit because if any of the electrical appliance stops working, it affects all the other appliances.
- ScienceClass 10ICSE
Which type of circuit, series or parallel, is preferred while connecting a large number of bulbs: a) for decorating a hotel building from outside? for lighting inside the rooms of the hotel?
Following type of circuit is used when: hotel building is to be decorated from outside: series lighting the rooms inside the hotel: parallel