Advanced Physics 2: 2021 MCQ

Ultrasound can be used to investigate the structure of organs of the human body using the pulse-echo technique. The level of detail obtained depends on the wavelength and the length of the pulses. Which line of the table shows a change to wavelength and a change to pulse length that would each improve the level of detail?

• A.

• B.

• C.

• D.

An object is placed in front of a lens. Which row of the table shows a combination that will produce a real image of the object?

• A.

• B.

• C.

• D.

What is the stiffness of the combination of springs?

• k/2

• k

• 2k

• 4k

What is the elastic strain energy stored for the combination of springs?

• E/2

• E

• 2E

• 8E

A mass of 24 kg is suspended from a steel wire of length 1.5 m. The wire has cross-sectional area 3.1 × 10⁻⁶ m². The Young modulus of steel is 1.8 × 10¹¹ Pa. Which of the following gives the extension of the wire?

• A

• B

• C

• D

The diagram shows a source of sound waves and an observer.

• Source: moves to the right at 20 m/s, Observer: moves to the left at 20 m/s

• Source: moves to the right at 20 m/s, Observer: moves to the right at 20 m/s

• Source: moves to the right at 20 m/s, Observer: stationary

• Source: stationary, Observer: moves to the right at 20 m/s

The photoelectric effect provides evidence for the particle nature of electromagnetic radiation. Which of the following observations of the photoelectric effect could also be explained using the wave nature of electromagnetic radiation?

• The emission of photoelectrons is instantaneous.

• The maximum kinetic energy of photoelectrons depends on frequency.

• The rate of emission of photoelectrons depends on intensity.

• There is a minimum frequency for emission of photoelectrons to occur.

The acceleration of free fall at the surface of the Earth is 9.81 ms⁻². The mass of the Earth is M and the diameter of the Earth is D.

• A

• B

• C

• D

A mass is suspended from a spring and allowed to come to equilibrium. The mass is displaced vertically and moves with simple harmonic motion. The graph shows how the resultant force on the mass varies with time.

• Graph A

• Graph B

• Graph C

• Graph D

The diagram represents an arrangement used to generate standing waves on a string. A standing wave pattern with two nodes is obtained as shown. Which of the following single changes could produce a standing wave pattern with three nodes?

• decreasing the distance between the vibration generator and pulley

• decreasing the frequency of the vibration generator

• decreasing the mass on the mass hanger

• decreasing the mass per unit length of the string