Let the resistance of an electrical component remains constant while the potential difference across the two ends of the component decreases to half of its former value. Answer An ammeter should be connected in the circuit in series with the resistors. The values of the current for different values of the voltage are shown in the given table. The Central Board of Secondary Education is one of the oldest and most popular boards in the country. In this reaction, sodium carbonate and calcium chloride exchange ions to form two new compounds.
What is the resistance of an electric iron connected to the same source that takes as much current as all three appliances, and what is the current through it? Baking powder is a mixture of baking soda and a mild acid known as tartaric acid. Ohm's law can be used to obtain the readings of ammeter and voltmeter. Also, we will learn about the various types of chemical reactions. An electric heater of resistance 8 Ω draws 15 A from the service mains 2 hours. Answer i Sodium Na is oxidised as it gains oxygen and oxygen gets reduced.
Heating effect of electric current and its applications in daily life. The resistance of a conductor depends on following factors. Define the unit of current. A piece of wire has a resistance R. Unfortunately, interest and hard work alone are not enough. It does not burn readily at a high temperature. On the other hand, oxygen reacts with food substances and makes them rancid.
The reading of the voltmeter will be 2. A drop of the solution in A is put on the red litmus paper. Remaining questions are of short and long answer type. Enjoy learning with great experience. The rate of consumption of electric energy in an electric appliance is called electric power. In other words, combination reactions are exothermic.
What would be the readings in the ammeter and the voltmeter? Answer If we connect the resistors in series, then the equivalent resistance will be the sum of the resistors, i. Answer In a displacement reaction, a more reactive element replaces a less reactive element from a compound. Two conducting wires of the same material and of equal lengths and equal diameters are first connected in series and then parallel in a circuit across the same potential difference. What are the advantages of connecting electrical devices in parallel with the battery instead of connecting them in series? In the second chapter, we will learn about the various types of acids, bases and salts and their reactions with metals and non-metals. Therefore, the amount of current flowing through the electrical component is reduced by half.
Exercise solution Question 1: Which of the statements about the reaction below are incorrect? Question 1: Why does the colour of copper sulphate solution change when an iron nail is dipped in it? Hence, tungsten is mainly used as heating element of electric bulbs. When a 12 V battery is connected across an unknown resistor, there is a current of 2. Question 18: Why do we apply paint on iron articles? In the third question, we have to name the elements as per the questions asked. An electric bulb is rated 220 V and 100 W. Refraction of light by spherical lens; Image formed by spherical lenses; Lens formula Derivation not required ; Magnification.
Hence, it is the best conductor. Electric power, Interrelation between P, V, I and R. On what factors does the resistance of a conductor depend? How much energy is given to each coulomb of charge passing through a 6 V battery? For example, the taste and smell of butter changes when kept for long. Note:- I have solved this question for the sake of clarity. The sixth chapter is about the various life processes which human need for their survival.
Hence, in a chemical reaction, the total mass of reactants should be equal to the total mass of the products. They are good conductors of electricity. The last chapter is about the conservation of natural resources. Chapter 5 - Periodic Classification of Elements There are ten questions in the chapter. Several electric bulbs designed to be used on a 220 V electric supply line, are rated 10 W.
Thus, bags used in packing food items are flushed with nitrogen gas to remove oxygen inside the pack. The reaction is as follows: Although aqueous solutions of glucose and alcohol contain hydrogen, these cannot dissociate in water to form hydrogen ions. The resistances are connected in series. The special name of this combustion reaction is respiration. Video Solution Answer: There is no current division occurring in a series circuit.