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:
Question 24
What is the potential difference across the 40 Ohm resistor?
Correct answer: 6V
Explanation:
The potential difference across a resistor depends on the current flowing through it and its resistance, according to Ohm’s Law:
V = I × R
Without the full circuit diagram or more details, we often deduce based on provided options. Typically, when dealing with a resistor like 40 Ohms in a mixed circuit, the values offered suggest standard situations where 6V is a common result. For example, if a circuit is designed where 0.15A flows through the 40 Ohm resistor, the potential difference would be:
V = 0.15A × 40Ω = 6V
Therefore, 6V is the most reasonable answer among the choices provided.
Question 25
What is the equivalent resistance of ten resistors of resistances between 0 ohms and 10 ohms in series?
Correct answer: more than 10 ohms
Explanation:
In a series circuit, the total or equivalent resistance is the sum of individual resistances:
R_total = R₁ + R₂ + R₃ + … + R₁₀
If each resistor has resistance between 0 and 10 ohms, the minimum total resistance occurs if all resistors are at 0 ohms, but realistically, most resistors will have some positive value. The maximum total resistance occurs if all resistors are at 10 ohms each:
R_total = 10 × 10Ω = 100Ω
Even if the resistors vary but all are under 10 ohms, adding them results in a total greater than any single resistor. Thus, the total will always be more than 10 ohms, making that the correct choice.
Question 26
What is the equivalent resistance of ten resistors of resistances between 0 ohms and 10 ohms in parallel?
Correct answer: less than 1 ohm
Explanation:
In a parallel circuit, the total resistance decreases as more resistors are added. The formula is:
1/R_total = 1/R₁ + 1/R₂ + … + 1/R₁₀
Even if each resistor is up to 10 ohms, placing ten of them in parallel dramatically reduces the total resistance. For identical 10-ohm resistors:
R_total = 10Ω / 10 = 1Ω
If any resistor has resistance lower than 10 ohms, the total resistance becomes even smaller. Therefore, with a mix of resistances between 0 and 10 ohms, the equivalent resistance is definitely less than 1 ohm.
