Question
Which statement about the orbits of comets is correct?
A Comets have elliptical orbits and the Sun is at the centre of the orbit.
B Comets have elliptical orbits and the Sun is not at the centre of the orbit.
C Comets have circular orbits and the Sun is at the centre of the orbit.
D Comets have circular orbits and the Sun is not at the centre of the orbit.
▶️Answer/Explanation
Ans: B
Question
Which quantity can be determined using the brightness of a supernova in a distant galaxy?
A the speed at which the galaxy is moving away from the Earth
B the distance of the galaxy from the Earth
C the Hubble constant
D the age of the Universe
▶️Answer/Explanation
Ans: B
Question
Which nuclear reaction powers a stable star?
A nuclear fission of nuclei producing hydrogen
B nuclear fission of a uranium nucleus into a krypton nucleus and a barium nucleus
C nuclear fusion of a krypton nucleus and a barium nucleus into a uranium nucleus
D nuclear fusion of hydrogen nuclei producing helium
▶️Answer/Explanation
Ans: D