The motion of-a car along a straight path is shown by the following figure:

1 The carstarts from 0 and reaches at A, B and C at different instants of time. During its motion from O to C and back to B, the distance covered and the magnitude of the displacement. are, respectively

• 25 km and 60 km

• 95 km and 35 km

• 60 km and 25 km

• 85 km and 35 km

Along a streamline flow of fluid:

• the velocity of all fluid particles at a given instant is constant

• the speed of a fluid particle remains constant

• the velocity of all fluid particles crossing a given position is constant

• the velocity of a fluid particle remains constant

How is the kinetic energy of a moving object affected if the net work done on it is positive?

• Decreases

• Increases

• Remains constant

• Becomes zero

A particle is executing simple harmonic motion. Which one of the following statements about the acceleration of the oscillating particle is true?

• It is always in the opposite direction to velocity

• It is proportional to the frequency of oscillation

• It is minimum when the speed is maximum

• It decreases as the potential energy increases

Which one of the following four particles, whose displacement x and acceleration a, are related as follows, is executing simple harmonic motion?

• a_x = + 3x

• a_x = +3x²

• a_x = -3x²

• a_x = -3x

If we plot a graph between volume V and inverse of pressure P (i.e.,$\frac{1}{\text{P}}$) for an ideal gas at constant temperature T, the curve so obtained is:

• straight line

• circle

• parabola

• hyperbola

Which one of the following statements is correct?

• The speed of sound waves in a medium depends upon the elastic property of the medium but not on inertia property

• The speed of sound waves in a medium depends upon the inertia property of the medium but not on elastic property

• The speed of sound waves in a medium depends neither on its elastic property nor on its inertia property

• The speed of sound waves in a medium depends both on elastic and inertia properties of the medium

Which one of the following statements is not correct?

• Pitch of a sound is its characteristic by which we can generally differentiate between a male voice and a female voice

• The loudness of sound is related to its frequency

• A musical sound has certain well defined frequencies which are generally harmonics of a fundamental frequency

• The timbre of a particular musical sound is related to the waveform of the sound wave

139.

A particle executes linear simple harmonic motion with amplitude of 2 cm. When the particle is at 1 cm from the mean position, the magnitudes ofthe velocity and the acceleration are equal. Then its time period (in seconds) is

• $\frac{2\mathrm{\pi }}{\sqrt{3}}$

• $\frac{\sqrt{3}}{2\mathrm{\pi }}$

• $\frac{\sqrt{3}}{\mathrm{\pi }}$

• $\frac{1}{2\mathrm{\pi }\sqrt{3}}$

Which ofthe following items is used in the household wirings to prevent accidental fire in case of short circuit?

• Insulated wire

• Plastic switches

• Non-metallic coatings on conducting wires

• Electric fuse