NCERT Solutions for Class 10 Science Chapter 12
NCERT Solutions for Class 10 Science Chapter 12 Electricity answers of intext questions given on Page 200 or Page 202 or Page 209 or Page 213 or Page 216 or Page 218 or Page 220 or Exercises in English Medium.All the solutions are updated for new academic session 2020-21. 10th Science Chapter 12 answers given on पेज 222 के उत्तर or पेज 224 के उत्तर or पेज 232 के उत्तर or पेज 237 के उत्तर or पेज 240 के उत्तर or पेज 242 के उत्तर or पेज 245 के उत्तर and अभ्यास के प्रश्न उत्तर in Hindi medium are also given free to download. NCERT Solutions Offline Apps 2020-21 are based on latest NCERT Books 2020-21 following the new CBSE Syllabus 2020-2021.
NCERT Solutions for Class 10 Science Chapter 12
|Subject:||Science – Physics|
10th Science Chapter 12 Answers in English & Hindi Medium
NCERT Solutions for Class 10 Science Chapter 12 Electricity all question answers, whether intext or exercises questions. All are updated as per student’s suggestions for 2020-21. Download NCERT Solutions as well as Offline Apps for other subjects also. Offline Apps are such that once downloaded, no need of internet later on.
10th Science Chapter 12 Answers in English Medium
10th Science Chapter 12 Answers in Hindi Medium
10th Science Chapter 12 Answers in PDF Form
What is meant by resistance of a conductor?
Resistance: The resistance of a conductor is its property by virtue of which it opposes the flow of current through it. It is equal to the ratio of the potential difference applied across the conductor to the current flowing through it.
Resistance = Potential difference / Current Or R = V/I.
What is an electric circuit? Distinguish between an open and a closed circuit.
A closed and continuous path along which an electric current flows is called an electric circuit.
In a torch, a switch provides a conducting link between a battery (a number of cells placed in proper order) and a bulb. When the switch is turned ON, an electric current flow through the bulb and its gives light. Such a continuous and closed path on an electric current is called an electric circuit. When the circuit is broken anywhere (or switch is turned OFF), the current stops flowing ant the bulb does not glow. An electric circuit through which no current flows is called an open circuit. An electric circuit through which current flows continuously is called a closed circuit.
What is meant by potential difference between two points? What is the SI unit of potential difference?
Potential difference: The potential difference between two points in an electric field is the amount of work done in bringing a unit positive charge from one point to the other.
V = W/Q or Potential difference = Work done / Charge
The SI unit of potential difference is joule/coulomb or volt.
Give four reasons why nichrome element is commonly used in household appliances.
In most of the household heating appliance, nichrome element is used because of the following reasons:
(i) Its melting point is high.
(ii) Its resistivity is large.
(iii) It can be easily drawn into thin wire.
(iv) It is not easily oxidised by the oxygen of the air when heated.
Questions for Practice
State Ohm’s law and write the condition in which this law is obeyed?
This law states that the current (I) flowing through a conductor is directly proportional to the potential difference (V) applied across its ends, provided the temperature and other physical condition remain unchanged.
Mathematically, V ∝ I or V = RI
The proportionality constant R is called the resistance of the conductor.
What is an ammeter? How is it connected in a circuit?
Ammeter: An ammeter (ampere + meter) is a device used to measure electric current in a circuit. An ammeter is always connected in series in a circuit, so that entire current, which we wish to measure, flows through it.
Questions from Board Papers
Distinguish between conventional current and electronic current. Or In an electric circuit state the relationship between the direction of conventional current and the direction of flow of electrons.
conventional current and electronic current: When a conductor AB is connected across the terminals of a cell , free electrons begin to drift or move from its end B (connected to the negative terminal of the cell) to the end A (connected to the positive terminal of the cell). The current constituted by flowing electrons is called electronic current. Clearly, the direction of electronic current is from negative terminal to positive terminal.
By convention, the direction of motion of positive charges is taken as the direction of electric current. It is from positive terminal to negative terminal. As the electrons are negatively charged, the direction of conventional current is an electric circuit is taken as opposite to the direction of the flow of electrons.
Why does the cord of an electric heater not glow while the heating element does?
Both the cord and the heating element of an electric heater carry the same current. But the heating element becomes hot due to its high resistance (H=I²Rt) and begins to glow. The cord remains cold due to its low resistance and dos not glow.
Important Questions on 10th Science Chapter 12
R = R1 + R2 + R3 + R4 + R5 = ⟹ R= 0.2 Ω + 0.3 Ω + 0.4 Ω + 0.5 Ω + 12 Ω =13.4 Ω
According to Ohm’s law, V = IR
I = V/R = 9/13.4 = 0.67 A
There is no current division occurring in a series circuit. So, the current through the 12 Ω resistor will be same as 0.67 A.
For the TV set:
Power W = 250 W and time t = 1 hour = 3600 seconds
So, energy consumed H = 250 × 3600 = 900000 J
For the toaster:
Power W = 1200 W and time t = 10 minutes = 600 seconds
So, energy consumed H = 1200 × 600 = 720000 J
Hence, TV set uses more energy than toaster.
V = W/Q
1 V = 1 j / 1 C
Length of the conductor
Cross-sectional area of the conductor
Material of the conductor
Temperature of the conductor.
H = I^2 Rt
The resistance of the element of an electric heater is very high. As current flows through the heating element, it becomes too hot and glows red. On the other hand, the resistance of the cord is low. It does not become red when current flows through it.