Q39
4 marksSection E

Study the circuit shown in which two resistors X and Y of resistances 3Ω3 \Omega and 6Ω6 \Omega respectively are joined in series with a battery of 2 V2 \text{ V}. (I) Draw a circuit diagram showing the above two resistors X and Y joined in parallel with same battery and same ammeter and voltmeter. (II) In which combination of resistors will the (i) potential difference across X and Y and (ii) current through X and Y, be the same? (III) (a) Find the current drawn from the battery by the series combination of the two resistors (X and Y). OR (III) (b) Determine the equivalent resistance of the parallel combination of the two resistors (X and Y).

Figure for question 39
Chemical Reactions and Equations
Circuit Diagrams
Official Answer

I

circuit diagramparallel combinationseries combinationequivalent resistanceOhm's law

Marking Scheme

  • 1I
  • 2II
  • 3III (a)

Hint

To solve this problem, we need to understand the concept of series and parallel circuits and how to calculate the equivalent resistance of a parallel combination of resistors. We also need to apply Ohm's law to find the current drawn from the battery by the series combination of the two resistors.

Quick Oral Answer

The circuit diagram for the parallel combination of resistors X and Y with the same battery and ammeter and voltmeter shows that both resistors have the same potential difference across them, which is equal to the voltage of the battery. The current through each resistor is different, depending on its resistance. The equivalent resistance of the parallel combination can be calculated using the formula: 1/R_eq = 1/R_X + 1/R_Y. In this case, R_X = 3 ohms and R_Y = 6 ohms, so the equivalent resistance is: 1/R_eq = 1/3 + 1/6 = 1/2 ohms. Therefore, the equivalent resistance of the parallel combination is 2 ohms. To find the current drawn from the battery by the series combination of the two resistors, we can use Ohm's law: I = V/R, where I is the current, V is the voltage, and R is the total resistance. The total resistance of the series combination is the sum of the individual resistances: R_total = R_X + R_Y = 3 + 6 = 9 ohms. The voltage of the battery is 2 volts, so the current drawn from the battery is: I = 2/9 = 0.22 amps. Therefore, the current drawn from the battery by the series combination of the two resistors is 0.22 amps.

Analysis & Explanation

The circuit diagram for the parallel combination of resistors X and Y with the same battery and ammeter and voltmeter shows that both resistors have the same potential difference across them, which is equal to the voltage of the battery. The current through each resistor is different, depending on its resistance. The equivalent resistance of the parallel combination can be calculated using the formula: 1/Req = 1/RX + 1/RY. In this case, RX = 3 ohms and RY = 6 ohms, so the equivalent resistance is: 1/Req = 1/3 + 1/6 = 1/2 ohms. Therefore, the equivalent resistance of the parallel combination is 2 ohms. To find the current drawn from the battery by the series combination of the two resistors, we can use Ohm's law: I = V/R, where I is the current, V is the voltage, and R is the total resistance. The total resistance of the series combination is the sum of the individual resistances: Rtotal = RX + R_Y = 3 + 6 = 9 ohms. The voltage of the battery is 2 volts, so the current drawn from the battery is: I = 2/9 = 0.22 amps. Therefore, the current drawn from the battery by the series combination of the two resistors is 0.22 amps.

Common Mistakes

  1. 1confusing series and parallel circuits
  2. 2not calculating the equivalent resistance correctly
  3. 3not applying Ohm's law correctly

Interesting Facts

The concept of series and parallel circuits is important in understanding how electronic devices work.

The equivalent resistance of a parallel combination of resistors can be calculated using the formula: 1/R_eq = 1/R_X + 1/R_Y.

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Frequently Asked Questions

How many marks does this question carry in CBSE Class 10 Science 2025?

This question carries 4 marks in the CBSE Class 10 Science 2025 examination.

Which chapter does this question come from in Science?

This question is from the chapter "Chemical Reactions and Equations" in the CBSE Class 10 Science syllabus.

What topic does this question cover in Science?

This question covers the topic "Circuit Diagrams" from CBSE Class 10 Science.

What type of question is this in the CBSE Class 10 Science 2025 paper?

This question appears in Section E in the CBSE Class 10 Science 2025 paper.