Physics questions and answers

Physics Questions and Answers

If you want to learn more about the nature and properties of matter and energy or you're simply preparing for a Physics exam, these Physics past questions and answers are ideal for you.

441.

Which of the following bodies, each with centre of gravity G, lying on a horizontal table, is/are in unstable equilibrium?

A.

II only

B.

III only

C.

I & IV only

D.

II & III only

Correct answer is B

- I & II are in neutral equilibrium. They will roll continuously on the table
- III is a body with high centre of gravity (unstable)
- IV is a body with high centre of gravity (stable)

442.

"Sum of all forces acting on a body is zero." This condition represents equilibrium'

A.

First condition

B.

Second condition

C.

Third condition

D.

Fourth condition

Correct answer is A

First condition

443.

A well 1km deep is filled with a liquid of density 950kg/m\(^3\) and g = 10m/s\(^2\), the pressure at the bottom of the well is

A.

9.6 × 10\(^6\)N/m\(^2\)

B.

9.5 x 10\(^5\)N/m\(^2\)

C.

9.4 x 10\(^6\)N/m\(^2\)

D.

9.5 x 10\(^6\)N/m\(^2\)

Correct answer is A

P = Pa + ρgh = (1.00 × 10\(^5\)) + (950 × 10 × 1000)
P = 10\(^5\) + (95 × 10\(^5\)) = 10\(^5\)(1 + 95) = 96 × 10\(^5\)
P = 9.6 × 10\(^6\) N/m\(^2\)

444.

Efficiency of conduction in liquids and gases compared to solids is

A.

less efficient than solid

B.

more efficient than solids

C.

equally efficient to solids

D.

efficiently may vary

Correct answer is A

Efficiency of conduction in liquids and gases compared to solids is less efficient than solid.

445.

Which of the following statements is/are correct for a freely falling body?
I. the total is entirely kinetic
II. the ratio of potential energy to kinetic energy is constant
III. the sum of potential and kinetic energy is constant

A.

I only

B.

II only

C.

III only

D.

I & III only

Correct answer is C

- the total energy at any point is a combination of the P.E and K.E
- the sum of PE and KE at any point is always constant not the ratio of P.E to K.E