Q6
1 markMCQSection A

The values of mA and μA\mu A are

Electricity
Electric Current and Circuit

Options

(A)10−6 A10^{-6} \text{ A} and 10−9 A10^{-9} \text{ A} respectively
(B)10−3 A10^{-3} \text{ A} and 10−6 A10^{-6} \text{ A} respectively
(C)10−3 A10^{-3} \text{ A} and 10−9 A10^{-9} \text{ A} respectively
(D)10−6 A10^{-6} \text{ A} and 10−3 A10^{-3} \text{ A} respectively
Official Answer

Option B is correct.

milliamperemicroampere10^-3 A10^-6 A

Marking Scheme

  • 11 mark for identifying the correct values of mA and μ\muA as 10−310^{-3} A and 10−610^{-6} A respectively.

Hint

Recall the prefixes 'milli-' (10−310^{-3}) and 'micro-' (10−610^{-6}) used for units of current.

Quick Oral Answer

One milliampere is equal to 10−310^{-3} amperes, and one microampere is equal to 10−610^{-6} amperes.

Analysis & Explanation

According to the NCERT text, small quantities of current are expressed in milliampere (1 mA=10−3 A1 \text{ mA} = 10^{-3} \text{ A}) or in microampere (1 μA=10−6 A1 \text{ } \mu\text{A} = 10^{-6} \text{ A}).


  • Why Option B is correct: It correctly identifies 1 mA=10−3 A1 \text{ mA} = 10^{-3} \text{ A} and 1 μA=10−6 A1 \text{ } \mu\text{A} = 10^{-6} \text{ A}.
  • Why other options are incorrect:
  • Option A: 10−6 A10^{-6} \text{ A} is microampere and 10−9 A10^{-9} \text{ A} is nanoampere, which is incorrect for mA.
  • Option C: 10−9 A10^{-9} \text{ A} is nanoampere, not microampere.
  • Option D: The values are swapped; 10−6 A10^{-6} \text{ A} is microampere and 10−3 A10^{-3} \text{ A} is milliampere.

Common Mistakes

  1. 1Confusing microampere (μ\muA) with nanoampere (nA) which is 10−910^{-9} A.
  2. 2Swapping the values of milli and micro.

Interesting Facts

The unit ampere is named after André-Marie Ampère, one of the main founders of classical electromagnetism.

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Frequently Asked Questions

How many marks does this question carry in CBSE Class 10 Science 2020?

This question carries 1 mark in the CBSE Class 10 Science 2020 examination.

Which chapter does this question come from in Science?

This question is from the chapter "Electricity" in the CBSE Class 10 Science syllabus.

What topic does this question cover in Science?

This question covers the topic "Electric Current and Circuit" from CBSE Class 10 Science.

What type of question is this in the CBSE Class 10 Science 2020 paper?

This is a MCQ question from Section A in the CBSE Class 10 Science 2020 paper.