A resistor of 7 Ω has 8 V across it. Enter the current in amperes.
Correct Answer: 1.143
Explanation:
Ohm’s law gives I=V/R=8/7=1.143 A.
MCQ Collection
china-gaokao-physics MCQs
Practice china-gaokao-physics questions with answers and explanations.
A wave has frequency 6 Hz and wavelength 1 m. Enter its speed.
Correct Answer: 6
Explanation:
Wave speed v=fλ=6×1=6 m/s.
Practice context 12: Which statement correctly expresses conservation of momentum?
Choose an option to check your answer.
Correct Answer: A. The total momentum of an isolated system remains constant
Explanation:
In an isolated system, internal forces occur in equal and opposite pairs, so total momentum is constant.
Practice context 12: For a transverse wave, how is the oscillation direction related to propagation?
Choose an option to check your answer.
Correct Answer: A. It is perpendicular to the direction of wave propagation
Explanation:
A transverse wave oscillates perpendicular to the direction in which the wave travels.
Practice context 12: Which definition of electric-field direction is correct?
Choose an option to check your answer.
Correct Answer: B. The electric field points in the direction a positive test charge would accelerate
Explanation:
Electric-field direction is defined by the force direction on a positive test charge.
Practice context 12: Which statement about a thin convex lens is correct?
Choose an option to check your answer.
Correct Answer: A. A convex lens can converge parallel rays to a real focus
Explanation:
A convex lens is converging and brings parallel incident rays toward its principal focus.
Practice context 12: Which statement correctly defines radioactive half-life?
Choose an option to check your answer.
Correct Answer: D. The half-life is the time for the number of undecayed nuclei to fall to half its initial value
Explanation:
Half-life is a characteristic decay time at which the undecayed population becomes one half.
A net force accelerates a 6 kg mass at 6 m/s². Enter the force in newtons.
Correct Answer: 36
Explanation:
Newton’s second law gives F=ma=6×6=36 N.
Enter the kinetic energy of a 2 kg object moving at 6 m/s.
Correct Answer: 36
Explanation:
K=½mv²=½×2×6²=36.0 J.
Practice context 11: Which statement correctly expresses conservation of momentum?
Choose an option to check your answer.
Correct Answer: C. The total momentum of an isolated system remains constant
Explanation:
In an isolated system, internal forces occur in equal and opposite pairs, so total momentum is constant.
Practice context 11: For a transverse wave, how is the oscillation direction related to propagation?
Choose an option to check your answer.
Correct Answer: D. It is perpendicular to the direction of wave propagation
Explanation:
A transverse wave oscillates perpendicular to the direction in which the wave travels.
Practice context 11: Which definition of electric-field direction is correct?
Choose an option to check your answer.
Correct Answer: C. The electric field points in the direction a positive test charge would accelerate
Explanation:
Electric-field direction is defined by the force direction on a positive test charge.