1
KCET 2022
MCQ (Single Correct Answer)
+1
-0

A tiny spherical oil drop carrying a net charge $$q$$ is balanced in still air, with a vertical uniform electric field of strength $$\frac{81}{7} \pi \times 10^5 \mathrm{~V} / \mathrm{m}$$. When the field is switched OFF, the drop is observed to fall with terminal velocity $$2 \times 10^{-3} \mathrm{~ms}^{-1}$$. Here $$g=9.8 \mathrm{~m} / \mathrm{s}^2$$, viscosity of air is $$1.8 \times 10^{-5} \mathrm{Ns} / \mathrm{m}^2$$ and density of oil is $$900 \mathrm{~kg} \mathrm{~m}^{-3}$$. The magnitude of $$q$$ is

A
$$8 \times 10^{-19} \mathrm{C}$$
B
$$1.6 \times 10^{-19} \mathrm{C}$$
C
$$3.2 \times 10^{-19} \mathrm{C}$$
D
$$0.8 \times 10^{-19} \mathrm{C}$$
2
KCET 2022
MCQ (Single Correct Answer)
+1
-0

"Heat cannot be flow itself from a body at lower temperature to a body at higher temperature". This statement corresponds to

A
conservation of momentum
B
conservation of mass
C
first law of thermodynamics
D
second law of thermodynamics
3
KCET 2022
MCQ (Single Correct Answer)
+1
-0

A smooth chain of length $$2 \mathrm{~m}$$ is kept on a table such that its length of $$60 \mathrm{~cm}$$ hangs freely from the edge of the table. The total mass of the chain is $$4 \mathrm{~kg}$$. The work done in pulling the entire chain on the table is (Take, $$g=10 \mathrm{~m} / \mathrm{s}^2$$)

A
6.3 J
B
3.6 J
C
2.0 J
D
12.9 J
4
KCET 2022
MCQ (Single Correct Answer)
+1
-0

Electrical as well as gravitational affects can be thought to be caused by fields. Which of the following is true for an electrical or gravitational field?

A
Gravitational or electric field does not exist in the space around an object.
B
Fields are useful for understanding forces actin through a distance.
C
There is no way to verify the existence of a force field since it is just a concept.
D
The field concept is often used to describe contact forces.