The graph of potential difference and current is an upward slanting straight line. Practice to excel and get familiar with the paper pattern and the type of questions. Example 3: An electric current of 15 A is flowing through an electric fan. ICSE Class 10. SI Unit of resistance is ohm. There is a relationship between potential difference and the current flowing through a conductor. Asked on October 15, 2019 by Litu Ghadage. Ohm’s law states that the voltage or potential difference between two points is directly proportional to the current or electricity passing through the resistance, and directly proportional to the resistance of the circuit.The formula for Ohm’s law is V=IR.This relationship between current, voltage, and relationship was discovered by German scientist Georg Simon Ohm. Check you answers with answer keys provided. In 1827, he observed that there was a relation between the current flowing through a metallic wire and potential difference across its terminals. Attach another nichrome wire of same thickness but double length, i.e. A stringed musical instrument, such as the sitar, is provided with a number of wires of different thickness. Tungsten has higher resistivity than aluminium. iii) Name the characteristics of sound which enables a person to differentiate between two sounds of the same soundness and frequency but produced by different instruments. (NCERT), Solution: Given V = 60 V then current = 4 A. For a given material, the current increases when the thickness is increased but length remains the same. For a given material, the current decreases when the length is increased but thickness remains same. If you are on a personal connection, like at home, you can run an anti-virus scan on your device to make sure it is not infected with malware. If resistance is doubled, the current shall become half. The resistivity of metals and alloys is in the range of 10-8 and 10-6. This means electric current will decrease with increase in resistance and vice versa. CBSE Class 10. Class 10 Science Home Page. State and explain Ohm's law. Resistance shows the property of a conductor by which it opposes the flow of electric charge through it. Ohm’s law states that the current flowing through a conductor is directly proportional to the potential difference applied across its ends. Important Note: Nichrome is an alloy of nickel, chromium, manganese and iron. Ohm's law is illustrated as in the figure below: What is the principle n which SONAR is based? This means; potential difference V varies as electric current. It is observed that the ratio between V and I is same in each case in this activity. The SI unit of resistance is Ohm (Ω). Classes. BNAT; CBSE. Precise measurements have shown that resistance of a uniform metallic conductor varies directly as its length and inversely as its area of cross section. Class 10 Electric Potential-Ohm’s Law. He has been teaching from … (NCERT), Example: How much current will an electric heater coil draw from a 220 V source if the resistance of the heater coil is 100 Ω? S t a t e m e n t: The electric current passing through a conductor is directly proportional to the potential difference across its ends provided temperature and other physical conditions remain constant. If V is the potential difference between two terminals of a metallic conductor and I is current, then according to Ohm’s Law; The value of R is constant for a given conductor at a given temperature. NCERT Books. Attach the nichrome wire of length l (marked as 1) in the circuit. Example 5: Calculate the potential difference between two points of a terminal, if an electric current of 10 A is flowing through it having resistance of 20Ω. First of all, connect a single cell in the circuit and switch on the key. (NCERT). Learn its definition, formula and more at BYJU'S . Metals and alloys have low resistivity and that is why they are good conductors of electricity. Statement of Ohm's Law: Ohm’s law states that at a constant temperature, current ' I' through a conductor between two points is directly proportional to the potential difference or voltage ' V', … Let us do the following actions to understand this. Answer. Pre Boards. Question 2 What is the resistance of an electric arc lamp,if the lamp uses 20 A when connected to a 220 Volt line? Where R is constant for the given conductor at a given temperature and called resistance. Ohm’s Law states that the potential difference between two terminals of a metallic conductor is directly proportional to the current flowing through it. It is harsh, discordant and displeasing to the air. Ohm’s Law. This means that silver is the best conductor of electricity. Voltage, i.e. Following observations could be made in this activity: By applying Ohm’s law, it is seen that resistance of a conductor depends on three factors, viz. Last Updated on May 4, 2020 By Mrs Shilpi Nagpal 2 Comments. Tungsten is almost exclusively used in filaments of bulbs. Connect an ammeter in series and connect a voltmeter in parallel to the nichrome wire which is shown by XY. The resistivity of insulators is in the range of 1012 and 1017. Completing the CAPTCHA proves you are a human and gives you temporary access to the web property. Let's learn every day from everyday life! Example 1: Calculate the resistance if 5 A of electric current flows through a conductor having potential difference between two points is equal to 15 V. Solution: Given, electric current (I) = 5 A.