Level_A_Test_04

The prefixes nano (n), micro (µ) and pico (p) are often used with units. Which row shows their correct values?

• A

• B

• C

• D

A crane has an arm to which is attached a frictionless pulley. A cable passes over the pulley and supports a load of 10 kN as shown. The crane arm exerts a force F on the pulley. What is the value of F?

• 10 kN.

• 17 kN.

• 14 kN.

• 7,7 kN.

The SI unit of specific heat capacity is Jkg^–1K^–1. What is the unit of specific heat capacity expressed in SI base units?

• ms^–2 K^–1

• kgms^–1 K^–1

• m²s^–2 K^–1

• kgm²s^–1 K^–1

Quantity X has a fractional uncertainty of x. Quantity Y has a fractional uncertainty of y. What is the fractional uncertainty in X/Y² ?

• x + y

• x – y

• x + 2y

• x – 2y

PQR and XYZ are wires in a circuit. A galvanometer connects Q and Y as a null indicator. When the galvanometer reads zero, which statement is correct?

• The potential difference between Q and Y is infinite.

• The potential difference between Q and Y is zero.

• The resistance between Q and Y is infinite.

• The resistance between Q and Y is zero.

An object has an initial velocity u and an acceleration a. The object moves in a straight line through a displacement s and has final velocity v. The above quantities are related by the equation shown: v² = u² + 2as. Which condition must be satisfied in order for this equation to apply to the motion of the object?

• The direction of a is constant and the direction of a is the same as the direction of s

• The direction of a is constant and the direction of a is the same as the direction of u.

• The magnitude of a is constant and the direction of a is constant.

• The magnitude of a is constant and the direction of a is the same as the direction of v.

A car is travelling at constant velocity. Its brakes are then applied, causing uniform deceleration. Which graph shows the variation with distance s of the velocity v of the car?

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A ball is thrown across a flat field. Which statement describes the motion of the ball, when the effects of air resistance are ignored?

• The ball lands with the same velocity at which it is thrown.

• The horizontal component of acceleration is constant throughout the motion.

• The horizontal and vertical components of acceleration are both zero at the highest point of the motion.

• The horizontal and vertical components of velocity are both zero at the highest point of the motion.

Which statement defines force?

• When a force acts on a body that is free to move, the force is the product of the mass of the body and its acceleration.

• When a force acts on a body that is free to move, the force is the rate of change of momentum of the body.

• When a force acts on a body that is free to move, the force is the work done by the force divided by the distance moved by the body.

• When a force acts on a lever and causes a moment, the force is the moment divided by the perpendicular distance of the force from the pivot.

A particle of mass m, travelling with speed u, collides with a stationary particle of mass M. The velocities of the two particles before and after the collision are shown. Which vector diagram correctly shows the momenta before and after the collision?

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