Which of the following statements about velocity is correct?
AVelocity is a scalar quantity that can never be negative
BVelocity is a vector quantity that includes both magnitude and direction
CVelocity and speed are always equal in magnitude
DVelocity remains constant in circular motion
Correct Answer:
B. Velocity is a vector quantity that includes both magnitude and direction
Explanation:
Velocity is a vector quantity with both magnitude and direction, unlike speed which is scalar. Velocity can be negative, and in circular motion, velocity constantly changes direction.
Which of the following has the highest specific heat capacity among common substances?
AIron
BWater
CCopper
DAluminum
Correct Answer:
B. Water
Explanation:
Water has specific heat capacity of 4186 J/(kg·°C), which is significantly higher than iron (~450), copper (~385), and aluminum (~900). This property makes water excellent for heat absorption and temperature regulation.
The SI unit of pressure is Pascal (Pa). How is it related to other SI units?
AN/m²
Bkg/(m·s²)
CJ/m³
DAll of the above
Correct Answer:
D. All of the above
Explanation:
Pascal = N/m² = kg/(m·s²) = J/m³. All these expressions are dimensionally equivalent representations of pressure, showing the fundamental relationship between force, area, and SI base units.
Two bodies of masses 2 kg and 3 kg are dropped from the same height in vacuum. Which statement is correct?
A2 kg mass reaches ground first
B3 kg mass reaches ground first
CBoth reach ground simultaneously
D2 kg mass falls slower due to lesser inertia
Correct Answer:
C. Both reach ground simultaneously
Explanation:
In vacuum, acceleration due to gravity is independent of mass. Both bodies experience the same gravitational acceleration (g ≈ 9.8 m/s²) and fall from the same height, so they reach the ground simultaneously.
A body moving in a circular path with constant speed possesses which type of acceleration?
AZero acceleration
BCentripetal acceleration directed toward the center
CTangential acceleration only
DUniform acceleration in the direction of motion
Correct Answer:
B. Centripetal acceleration directed toward the center
Explanation:
In uniform circular motion, speed is constant but direction changes continuously. This change in direction causes centripetal acceleration always directed toward the center of the circle.
The process by which plants prepare their food using sunlight is known as:
ARespiration
BPhotosynthesis
CFermentation
DTranspiration
Correct Answer:
B. Photosynthesis
Explanation:
Photosynthesis is the process where plants use sunlight, water, and CO₂ to produce glucose and oxygen. The equation is 6CO₂ + 6H₂O + light → C₆H₁₂O₆ + 6O₂.
