BCA STEM Concepts 3 — Questions and Answers
Question 1: A circuit has a 12-volt battery and a 4-ohm resistor. What current flows through it?
- 3 A (Correct answer)
- 48 A
- 8 A
- 0.33 A
Correct answer: 3 A
Using Ohm's Law, I = V/R = 12/4 = 3 amperes.
Question 2: What is the role of RNA polymerase in molecular biology?
- Transcribes DNA into mRNA (Correct answer)
- Translates mRNA into protein
- Replicates DNA
- Degrades damaged proteins
Correct answer: Transcribes DNA into mRNA
RNA polymerase reads the DNA template strand and synthesizes a complementary mRNA strand during transcription.
Question 3: In set theory, what does A ∩ B represent?
- Elements in both A and B (Correct answer)
- Elements in A or B or both
- Elements only in A
- Elements not in A or B
Correct answer: Elements in both A and B
The intersection A ∩ B contains only elements that belong to both set A and set B simultaneously.
Question 4: Which layer of the Earth is primarily composed of iron and nickel and generates Earth's magnetic field?
- Outer core (Correct answer)
- Mantle
- Crust
- Inner core
Correct answer: Outer core
The liquid outer core, composed of iron and nickel, generates Earth's magnetic field through convection currents.
Question 5: In programming, what does a 'function' or 'method' primarily allow developers to do?
- Reuse blocks of code without repetition (Correct answer)
- Store data persistently
- Increase processing speed automatically
- Connect to the internet
Correct answer: Reuse blocks of code without repetition
Functions encapsulate reusable logic so it can be called multiple times without duplicating code.
Question 6: What is the value of log₁₀(1000)?
- 3 (Correct answer)
- 10
- 100
- 0.001
Correct answer: 3
log₁₀(1000) = 3 because 10³ = 1000.
Question 7: Which type of chemical bond involves the sharing of electron pairs between atoms?
- Covalent bond (Correct answer)
- Ionic bond
- Metallic bond
- Hydrogen bond
Correct answer: Covalent bond
Covalent bonds form when atoms share one or more pairs of electrons, typically between nonmetals.
BCA STEM Concepts 3
A circuit has a 12-volt battery and a 4-ohm resistor.
What current flows through it?