10th
- What are the advantages of connecting electrical devices in parallel with the battery instead of connecting them in seri There is no division of voltage among the appliances when connected in parallel. The potential difference across each appliance is equal to... 1
- An electric lamp of 100 Ω, a toaster of resistance 50 Ω, and a water filter of resistance 500 Ω are connected https://youtu.be/MyGgXsAxodg 2
- Judge the equivalent resistance when the following are connected in parallel − (a) 1 Ω and 106Ω, (b) 1 Ω and 103Ω and (a) When 1 Ω and 10⁶ Ω are connected in parallel: Let R be the equivalent resistance. therefore 1/R = 1/1+1/10⁶ \\ R=10⁶/1+10⁶ simeq 10⁶/10⁶... 1
- Redraw the circuit of question 1, putting in an ammeter to measure the current through the resistors and a voltmeter to An ammeter should be connected in the circuit in series with the resistors. To measure the potential difference across the resistor it shoul... 1
- Draw a schematic diagram of a circuit consisting of a battery of three cells of 2 V each, a 5 Ω resistor Three cells of potential 2 V, each connected in series therefore the potential difference of the battery will be 2 V + 2 V + 2 V = 6V. The f... 1
- Use the data in Table 12.2 to answer the following - Table 12.2 Electrical resistivity of some substances at 20°C (a) Resistivity of iron = 10.0 x 10⁻⁸ Ω Resistivity of mercury = 94.0 x 10⁻⁸ Ω Resistivity of mercury is more than that of iron. This implie... 1
- Why are coils of electric toasters and electric irons made of an alloy rather than a pure metal? The resistivity of an alloy is higher than the pure metal. Moreover, at high temperatures, the alloys do not melt readily. Hence, the coils... 1
- Let the resistance of an electrical component remains constant while the potential difference across According to Ohm’s law V = IR ⇒ I=V/R ... (1) Now Potential difference is decreased to half ∴ New potential difference Vʹ=V/2 Resistance rem... 1
- Will current flow more easily through a thick wire or a thin wire of the same material, when connected to the The current will flow more easily through thick wire. It is because the resistance of a conductor is inversely proportional to its area of c... 1
- On what factors does the resistance of a conductor depend? The resistance of a conductor depends upon the following factors: Length of the conductor Cross-sectional area of the conductor Material of... 1
- How much energy is given to each coulomb of charge passing through a 6 V battery? The energy given to each coulomb of charge is equal to the amount of work which is done in moving it. Now we know that, Potential difference... 1
- What is meant by saying that the potential difference between two points is 1 V? If 1 J of work is required to move a charge of amount 1 C from one point to another, then it is said that the potential difference between t... 1
- Name a device that helps to maintain a potential difference across a conductor. Any source of electricity like battery, cell, power supply, etc. helps to maintain a potential difference across a conductor. 1
- Calculate the number of electrons constituting one coulomb of charge. One electron possesses a charge of 1.6 ×10⁻¹⁹C, i.e., 1.6 ×10⁻¹⁹C of charge is contained in 1 electron. ∴ 1 C of charge is contained in 1/1.... 1
- Define the unit of current The unit of electric current is ampere (A). 1 A is defined as the flow of 1 C of charge through a wire in 1 s. 1
- What does an electric circuit mean? A continuous and closed path of an electric current is called an electric circuit. An electric circuit consists of electric devices, source... 1
- What is the function of an earth wire? Why is it necessary to earth metallic appliances? The metallic body of electric appliances is connected to the earth by means of earth wire so that any leakage of electric current is transfe... 1
- When does an electric short circuit occur? If the insulation of the wires used in the circuit is damaged or the appliance used is faulty due to which the live wire and the neutral wir... 1
- Explain the underlying principle and working of an electric generator by drawing a labelled diagram. Principle: An electric generator works on the principle of electromagnetic induction phenomenon. According to it, whenever a coil is rotated... 1
- State the rule to determine the direction of a (i) magnetic field produced around a straight conductor-carrying current, (i) Maxwell's right hand thumb rule (ii) Fleming's left hand rule (iii) Fleming's right hand rule 1
- Two circular coils A and B are placed closed to each other. If the current in the coil A is changed, will some current Two circular coils A and B are placed close to each other. When the current in coil A is changed, the magnetic field associated with it also... 1
- A coil of insulated copper wire is connected to a galvanometer. What will happen if a bar magnet is (i) The needle of the galvanometer shows a momentary deflection in a particular direction. (ii) The needle of the galvanometer shows a momen... 1
- Name some devices in which electric motors are used? Some devices in which electric motors are Water pumps, Electric fans, Electric mixers and Washing machines. 1
- Draw a labelled diagram of an electric motor. Explain its principle and working. What is the function of a split ring https://lh3.googleusercontent.com/-QCgE9gUPJaU/YbgHE65MlaI/AAAAAAAAC78/XGDS2ET9w7IMJWW4uuiFe0KqFc7zJt0QQCNcBGAsYHQ/image.png Principle: It w... 1