All Free Physics MCQs with Answers
Every Physics question in the bank, across all chapters, each with the correct answer and a written explanation. Free and unlimited, with no account needed.
13,934 questions · page 697 of 697
- A. RH/9
- B. 9/RH
- C. 9 RH
- D. 9 + RH
Explanation: The shortest wavelength in a series is its series limit, where the electron falls from n = infinity.
Correct answer: 9/RH- A. Visible region
- B. Infrared region
- C. Ultraviolet region
- D. X-rays
Explanation: The Lyman series ends on n = 1, the largest energy drop of any hydrogen series, so its photons are the most energetic and shortest in…
Correct answer: Ultraviolet region- A. Pressure, but not volume or temperature
- B. Temperature, but not pressure or volume
- C. Volume, but not pressure or temperature
- D. Pressure and temperature, but not volume
Explanation: For an ideal gas the internal energy is purely the kinetic energy of its molecules, and that depends only on absolute temperature.
Correct answer: Temperature, but not pressure or volume- A. An α-particle
- B. A β-particle
- C. A γ-ray
- D. A neutron
Explanation: Aluminium-27 bombarded by an alpha particle gives phosphorus-30 plus a neutron.
Correct answer: A neutron- A. An α-particle
- B. An electron
- C. A proton
- D. A neutrino
Explanation: A neutrino carries no electric charge, which is a large part of why it interacts so weakly with matter and is so hard to detect.
Correct answer: A neutrino- A. Half
- B. Double
- C. 4 times
- D. Unchanged
Explanation: From PV = nRT, the volume is V = nRT/P. Doubling the absolute temperature multiplies the volume by 2 and quadrupling the pressure divides…
Correct answer: Half- A. Visible
- B. Ultraviolet
- C. Infrared
- D. None of the above
Explanation: Transitions ending on the second orbit form the Balmer series, and the Balmer lines fall in the visible region.
Correct answer: Visible- A. Slow neutron
- B. Thermal neutron
- C. Fast neutron
- D. Both (a) and (b)
Explanation: A neutron with a kinetic energy of a few hundredths of an electron volt has been slowed to roughly the thermal energy of its surroundings…
Correct answer: Slow neutron- A. A gas is cooled
- B. A plate is shattered
- C. An egg is scrambled
- D. A drop of dye diffuses in a cup of water
Explanation: Cooling a gas removes energy and reduces the number of microstates available to it, so its entropy falls.
Correct answer: A gas is cooled- A. I only
- B. II only
- C. III only
- D. I & II only
- E. I, II & III
Explanation: All three statements are standard postulates of the kinetic theory: a finite volume contains a very large number of molecules, molecular…
Correct answer: I, II & III- A. P decreases by a factor of 16
- B. P decreases by a factor of 4
- C. P decreases by a factor of 2
- D. P increases by a factor of 4
- E. P increases by a factor of 16
Explanation: From PV = nRT, the pressure is P = nRT/V. Multiplying the temperature by 2 doubles the pressure while multiplying the volume by 8 divides…
Correct answer: P decreases by a factor of 4- A. I only
- B. III only
- C. I and II only
- D. I and III only
- E. II and III only
Explanation: At constant pressure Charles's law makes volume proportional to absolute temperature, so statement I holds.
Correct answer: I and III only- A. 359.4 °F
- B. -459.4 °F
- C. 100 °F
- D. -259.4 °F
Explanation: Absolute zero is -273.15 C. Converting with F = (9/5)C + 32 gives (9/5)(-273.15) + 32 = -491.67 + 32 = -459.67 F, which this paper rounds…
Correct answer: -459.4 °F- A. 0K
- B. -273.15 C
- C. -459.4 F
- D. All of these
Explanation: Absolute zero is one temperature written on three scales: 0 K, -273.15 C and about -459.67 F.
Correct answer: All of these