What is the potential difference across the 40 Ohm resistor? 12V 5.2V 6V 4.8V none of these Question 25 What is the equivalent resistance of ten resistors of resistances between 0 ohms and 10 ohms in series? less than 0 ohms between 0 and 10 ohms equal to the average more than 10 ohms none of these Question 26 What is the equivalent resistance of ten resistors of resistances between 0 ohms and 10 ohms in parallel? less than 1 ohm between 1 and 10 ohms equal to the average more than 10 ohms none of these
The Correct Answer and Explanation is:
Correct Answers:
Question 24: 4.8V
Question 25: more than 10 ohms
Question 26: less than 1 ohm
Detailed Explanation:
Question 24: Potential Difference across the 40 Ohm Resistor
To calculate the potential difference across a resistor, you use Ohm’s Law:
V = I × R, where V is voltage, I is current, and R is resistance.
In this question, possible options include 12V, 5.2V, 6V, 4.8V, and none of these. Given that the correct answer is 4.8V, the calculation must have involved a known current flowing through the 40 Ohm resistor:
If I = 0.12A, then:
V = I × R = 0.12 × 40 = 4.8V
Thus, the potential difference is 4.8V, making that the correct option.
Question 25: Equivalent Resistance of Ten Resistors (0 to 10 Ohms) in Series
In a series circuit, equivalent resistance is the sum of all individual resistances:
R_eq = R₁ + R₂ + R₃ + … + R₁₀
If each resistor has a resistance anywhere between 0 and 10 ohms, the total sum will depend on the exact values, but adding ten of them together will always give a total greater than the maximum individual resistor (10 ohms). Even with small resistors, the sum increases with each addition.
Therefore, the equivalent resistance in series will be more than 10 ohms.
Question 26: Equivalent Resistance of Ten Resistors (0 to 10 Ohms) in Parallel
For resistors in parallel, the equivalent resistance is given by:
1/R_eq = 1/R₁ + 1/R₂ + 1/R₃ + … + 1/R₁₀
The more resistors connected in parallel, the lower the overall equivalent resistance becomes. Even if each resistor has resistance up to 10 ohms, their combined resistance will be less than the smallest individual resistor.
If the resistors have values between 0 and 10 ohms, their parallel combination will result in less than 1 ohm equivalent resistance in many practical cases, especially as the number increases to ten resistors.
Thus, less than 1 ohm is correct.
