Physics - Online Test
Q1.
A constant retarding force of 50 N is applied to a body of mass 20 kg moving initially with a speed of 15 m . How long does the body take to stop?
Answer : Option B
Explaination / Solution:
F=mdvdtdt=mdvF=20×1550=6s
Q2. Balram exerts a steady force of magnitude 150 N on the stalled car as shown in the figure below; he pushes it a distance of 20 m. The car also has a flat tyre, so to make the car move straight. He pushes at an angle of 30 to the direction of motion. How much work does he do?
Answer : Option B
Explaination / Solution:
W=Fscosθ=150×20×
3√2=2598J
Q3. What is the correct sequence of events technology gives rise to new science or new science gives rise to technology?
Answer : Option C
Explaination / Solution:
Technology is often a consequence of science and engineering, although technology as a human activity precedes the two fields. For example, science might study the flow of electrons in electrical conductors by using already-existing tools and knowledge. This new-found knowledge may then be used by engineers to create new tools and machines such as semiconductors, computers, and other forms of advanced technology.
Q4. A parallel plate condenser is immersed in an oil of dielectric constant 2. The field between the plates is
Answer : Option C
Explaination / Solution:
In the presence of a dielectric with K=2, the electric field =E/K= E/2, The force also reduces by 1/2
Q5. The moment of inertia of a circular ring about an axis passing through its centre and normal to its plane is 200 gm . Then its moment of inertia about a diameter is
Answer : Option D
Explaination / Solution:
applying perpendicular axis theorm
I = moment of inertia about a axis passing through diameter
I = 100 gm cm2
Q6. Two soap bubbles are blown simultaneously .In the first soap bubble, the excess pressure is 4 times of second soap bubble. The ratio of radii of first to second soap bubble is
Answer : Option B
Explaination / Solution:
No Explaination.
Q7. Three vessels of equal capacity have gases at the same temperature and pressure. The first vessel contains neon (monatomic), the second contains chlorine (diatomic), and the third contains uranium hexafluoride (polyatomic). The number of molecules
Answer : Option B
Explaination / Solution:
Avogadro's law states that, "equal volumes of all gases, at the same temperature and pressure, have the same number of molecules".
Q8. A far-sighted man who has lost his spectacles reads a book by looking through a small hole in the sheet of paper. Then
Answer : Option B
Explaination / Solution:
No Explaination.
Q9. An electric field can deflect
Answer : Option B
Explaination / Solution:
No Explaination.
Q10. In general, when a solid is heated, it
Answer : Option B
Explaination / Solution:
Δl=βVΔTΔA=αVΔTΔV=γVΔT
