Physics

In a Venturi meter, the fluid speed is maximum at the throat, which is the narrowest part of the meter. According to the principle of continuity, the velocity increases where the cross-sectional area decreases.

The shape of an airplane wing that generates lift is called an aerofoil (or airfoil) profile. This design allows air to flow faster over the top surface, creating lower pressure and thus lift.

The span (horizontal distance) of a broad jump depends primarily on the angle of projection, as it determines the trajectory and range of the jump. Other factors like mass or height of jump do not directly determine the horizontal distance covered.

When a body moves in a circle, its linear velocity is tangent to the circle, while its angular velocity vector points along the axis of rotation (perpendicular to the plane of motion). Therefore, the angle between linear velocity and angular velocity is always 90°.

A satellite orbiting the Earth is accelerating due to the centripetal force acting towards the Earth, making its frame of reference non-inertial. Inertial frames are those that are either at rest or move with constant velocity, without acceleration.

Reducing uncertainty in timing experiments can be achieved by using highly precise instruments to improve measurement accuracy and by counting the number of vibrations to increase the total measured time, thereby reducing relative error. Both methods together help minimize timing uncertainty.

The centripetal force required to keep a body moving in a circle of radius r at linear speed V is given by F = mV²/r, where m is the mass of the body. This force acts towards the center of the circle.

The linear speed v of a point on the rim of a wheel is given by v = circumference × revolutions per second. The wheel diameter is 1 m, so the circumference is π × 1 = π meters. The wheel makes 30 revolutions per minute, which is 30/60 = 0.5 revolutions per second. Therefore, the linear speed is π × 0.5 = π/2 meters per second. Hence, the correct answer is option B (π/2).

For a particle moving in a circle with angular velocity $\omega$, the acceleration of its projection on the diameter (x-axis) is given by $a=-{\omega }^{2}x$. The negative sign indicates direction, but since options do not show signs, the magnitude is ${\omega }^{2}x$. Option A correctly represents this as "w2x" (interpreted as ${\omega }^{2}x$).

The SI unit of force is the Newton, which is a proper noun and should be capitalized. Its symbol is 'N', also capitalized. Therefore, the correct pair is 'Newton, N'.