The echo (reflected sounD. will be distinctly heard only at ordinary temperatures if the distance of the reflecting surfaces from the source of sound is at least ________...?
(A) 1120 ft
(B) 120 ft
(C) 56 ft
(D) 100 ft
✅ Correct Answer:56 ft
Comments
The echo (reflected sounD. will be distinctly heard only at ordinary temperatures if the distance of the reflecting surfaces from the source of sound is at least ________...?
The radioactive isotopes are formed by neutrons bombardment on the nucleus, these incident neutrons must have ___ to penetrate in the nucleus....?
(A) Very high velocity
(B) Very low velocity
(C) Intermediate velocity
(D) All of these
✅ Correct Answer:Very high velocity
Comments
The radioactive isotopes are formed by neutrons bombardment on the nucleus, these incident neutrons must have ___ to penetrate in the nucleus....?
A man pulls a crate of mass 25 kg across the leveled ground with a horizontal force of 60 N. A constant force of friction of 20 N acts on the sledge. What is the acceleration of the sledge...?
(A) 0.63 ms^-2
(B) 1.6 ms^-2
(C) 2.4 ms^-2
(D) 3.2 ms^-2
✅ Correct Answer:1.6 ms^-2
Comments
A man pulls a crate of mass 25 kg across the leveled ground with a horizontal force of 60 N. A constant force of friction of 20 N acts on the sledge. What is the acceleration of the sledge...?
If the electrostatic force between two electrons is F Newton, then the electrostatic force between two protons at the same distance is _____...?
(A) F
(B) 0N
(C) 2F
(D) 2/3 F
✅ Correct Answer:F
Comments
If the electrostatic force between two electrons is F Newton, then the electrostatic force between two protons at the same distance is _____...?