BCA STEM Concepts 2 — Questions and Answers
Question 1: A wave traveling in a medium has a frequency of 440 Hz and a wavelength of 0.75 m. What is its wave speed?
- 330 m/s (Correct answer)
- 440 m/s
- 587 m/s
- 220 m/s
Correct answer: 330 m/s
Wave speed = frequency × wavelength = 440 × 0.75 = 330 m/s.
Question 2: In a chemical reaction, if the activation energy is lowered by a catalyst, what happens to the reaction rate?
- It increases (Correct answer)
- It decreases
- It remains unchanged
- It becomes zero
Correct answer: It increases
A catalyst lowers activation energy, allowing more molecules to overcome the energy barrier and increasing the reaction rate.
Question 3: Which data structure operates on a Last-In, First-Out (LIFO) principle?
- Stack (Correct answer)
- Queue
- Linked list
- Binary tree
Correct answer: Stack
A stack is a LIFO structure where the most recently added element is the first to be removed.
Question 4: The Pythagorean theorem states that in a right triangle with legs a and b and hypotenuse c, which equation holds?
- a² + b² = c² (Correct answer)
- a + b = c
- a² - b² = c²
- 2(a + b) = c
Correct answer: a² + b² = c²
The Pythagorean theorem is a² + b² = c², relating the squares of the legs to the square of the hypotenuse.
Question 5: What is the primary function of mitochondria in a eukaryotic cell?
- Produce ATP through cellular respiration (Correct answer)
- Synthesize proteins
- Store genetic information
- Regulate cell division
Correct answer: Produce ATP through cellular respiration
Mitochondria generate ATP via oxidative phosphorylation, earning the title 'powerhouse of the cell.'
Question 6: In computing, what does 'binary' refer to?
- A base-2 number system using only 0 and 1 (Correct answer)
- A base-10 number system
- A programming language
- A type of algorithm
Correct answer: A base-2 number system using only 0 and 1
Binary is a base-2 numeral system that uses only the digits 0 and 1, which directly maps to electronic on/off states.
Question 7: Which property of matter describes its resistance to changes in motion?
- Inertia (Correct answer)
- Momentum
- Velocity
- Acceleration
Correct answer: Inertia
Inertia is the tendency of an object to resist changes in its state of motion, as described by Newton's First Law.
BCA STEM Concepts 2
A wave traveling in a medium has a frequency of 440 Hz and a wavelength of 0.75 m.
What is its wave speed?