Title Practical Kida (1).pdf ✅

PracticalKida.com Practical No. 3 Determination of resistance by Ohm’s law. Table 1: Using Ammeter and Voltmeter Sr. No. Electric Current (Ampere) Potential Difference (volt) Resistance R (ohm) = V/I Mean Resistance R (ohm) 1 0.25 1.00 4.00 2 0.50 2.00 4.00 3 0.75 3.00 4.00 4 1.00 4.00 4.00 5 1.25 5.00 4.00 Mean Resistance: 4.00 ohms Table 2: Using Multimeter
PracticalKida.com Sr. No. Electric Current (Ampere) Potential Difference (volt) Resistance R (ohm) = V/I Mean Resistance R (ohm) 1 0.24 0.98 4.08 2 0.51 2.02 3.96 3 0.76 3.04 4.00 4 1.02 4.06 3.98 5 1.27 5.08 4.00 Resistance of given wire From observation (Ω) From graph (Ω) By using voltmeter and ammeter 4.00 4.00
PracticalKida.com By using multimeter 4.00 4.00 Conclusion: The experimental results demonstrate a strong linear relationship between current and voltage, confirming Ohm's Law. The resistance of the given wire, as determined using both voltmeter/ammeter and multimeter methods, is consistent and approximately 4.00 ohms. Practical Related Questions 1. State the function of rheostat in this lab experiment. Answer: The rheostat in this lab experiment serves as a variable resistor. Its primary function is to control the current flowing through the circuit. By adjusting the rheostat, you can increase or decrease the resistance in the circuit, thereby altering the current. This allows you to observe the effect of varying current on the voltage drop across the resistor and to verify Ohm's Law over a range of current values. 2. A potential difference of 15V appears across the ends of a resistor when 5A of current flows through it. Find resistance of the resistor? Answer: To find the resistance of the resistor, we can use Ohm's Law: R = V / I where:
PracticalKida.com ● R is the resistance ● V is the potential difference (voltage) ● I is the current Given: ● V = 15V ● I = 5A Plugging these values into the formula: R = 15V / 5A = 3 ohms Therefore, the resistance of the resistor is 3 ohms. 3. If the voltage across a fixed value of resistance is increased five times, what will be the variation in current? Does the resistance depend on the temperature? Answer: If the voltage across a fixed value of resistance is increased five times, the current will also increase five times. This is a direct consequence of Ohm's Law, which states that the current (I) flowing through a conductor is directly proportional to the potential difference (V) across it, provided the resistance (R) remains constant. Mathematically, this can be expressed as: V = IR If V is increased five times while R remains constant, then I must also increase five times to maintain the equality.