Physics Questions & Answers - Free Online Practice

196.

Suppose three identical steel balls Q, R, and S, are placed on an undulating ground as illustrated in the diagram above. Which of the balls is/are in neutral equilibrium?

S only

Q only

R only

Q and S only

View answer & explanation

Correct answer is A

A system is in neutral equilibrium if its equilibrium is independent of displacements from its original position. A marble S on a flat horizontal surface is an example.

197.

The linear expansivity, $\alpha$ , and cubic expansivity, $\gamma$ , of a material are related by the equation?

$\gamma$ =a

$\gamma$ =3 $\alpha$

$\gamma$ =2a

$\gamma$ = $\frac{1}{3} \alpha$

View answer & explanation

Correct answer is B

cubic and linear expansivity are related by this equation. γ=3α.

198.

The length of a simple pendulum is increased by a factor of four. By what factor is its period increase?

0.5 $\pi$

2 $\pi$

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Correct answer is B

The period of a simple pendulum is doubled, when its length is made four times.

199.

From the principle of flotation, a body sinks in a fluid until it displace a quantity equal to its own?

density

mass

weight

volume

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Correct answer is C

Archimede's Principle states that a body immersed in a fluid experiences an upthrust equal to the weight of the fluid displaced, and this is fundamental to the equilibrium of a body floating in still water.

200.

The area under a force-time graph represents--------

change in kinetic energy

change in momentum

change in work done

change in internal energy

View answer & explanation

Correct answer is B

It is a graph that represents the force that acts on a body in a certain amount of time.
Force on the object is represented by the y-axis and time taken by the object is represented by the y axis.
The area under the curve indicates the impulse, the change in momentum that the object undergoes.