The dimensional formula for energy density (energy per unit volume) is the same as that of: MCQ with Answer and Explanation

The dimensional formula for energy density (energy per unit volume) is the same as that of:
A. Momentum
B. Pressure
C. Power
D. Force
Answer: Option B
Solution (By JKExamLibrary)
Energy density = energy/volume. Energy has dimensions [ML²T⁻²], volume [L³], so energy density = [ML²T⁻²]/[L³] = [ML⁻¹T⁻²]. Pressure = force/area = [MLT⁻²]/[L²] = [ML⁻¹T⁻²], identical. Force is [MLT⁻²], power [ML²T⁻³], momentum [MLT⁻¹]. This equivalence explains why pressure appears in Bernoulli's equation alongside kinetic/potential energy density. Memory aid: 'Pressure and energy density share dimensions [ML⁻¹T⁻²]'. This dimensional analysis question tests ability to derive and compare formulas, frequently appearing in competitive exams to assess conceptual depth.

This question belongs to: Science Physics

Discuss this Question (0)

No comments yet. Be the first to start the discussion!

Practice More Physics Questions

Question #1 Report Error
Which of the following materials is diamagnetic in nature?
A. Nickel
B. Aluminum
C. Water
D. Iron

Correct Answer: Option C


Explanation:
Materials are classified by their magnetic properties. Ferromagnetic materials (Iron, Cobalt, Nickel) are strongly attracted to magnets. Paramagnetic materials (Aluminum, Platinum) are weakly attracted. Diamagnetic materials (Water, Bismuth, Copper, Gold) are actually weakly repelled by a magnetic field because they create an induced magnetic field in opposition to the externally applied one.

This question belongs to: Science Physics
Question #2 Report Error
Who formulated the Planetary Model of the atom, proposing that electrons orbit the nucleus in specific, quantized circular orbits?
A. Ernest Rutherford
B. J. J. Thomson
C. Albert Einstein
D. Niels Bohr

Correct Answer: Option D


Explanation:
Niels Bohr proposed the Bohr model of the atom in 1913. He improved upon Rutherford's model by introducing quantum theory, suggesting that electrons travel in discrete, quantized orbits around the nucleus without radiating energy, and that energy is only emitted or absorbed when an electron jumps between these specific orbits.

This question belongs to: Science Physics
Question #3 Report Error
The unit of electric power can be expressed as
A. Joule × second
B. Volt × ampere
C. Coulomb × volt
D. Ohm × meter

Correct Answer: Option B


Explanation:
P = V I, so watt = volt × ampere.

This question belongs to: Science Physics