Know the science behind universe

Science as a subject plays a major part of the General Studies paper in most competitive examinations like the Telangana State government recruitment tests.

These practice questions focusing on general science will aid aspirants to prepare better for the State government recruitment examinations.

1. With respect to the measurements of the acceleration ‘g’ due to the gravity of the Earth, different values of ‘g’ are found at different —?

1. Depths 2. Altitudes 3. Longitudes 4. Latitudes

Select the correct option from the codes given below:
a) 1& 2 b) 1, 2 & 3 c) 1, 2 & 4 d) 1, 2, 3 & 4

Ans: d

Explanation: All four options are correct because the Earth is not an exactly spherical body.

2. While passing over an obstacle, a light ray slightly bends round the corner. The phenomenon is known as —:

a) Scattering b) Polarisation c) Diffraction d) Refraction

Ans: c

Explanation: Diffraction refers to various phenomena which occur when a wave encounters an obstacle or a slit.

 

3. Echoes are heard when we shout in an empty hall. But when the hall is full of people, no echoes are heard. Why?

a) Echoes are subdued in the noise of people
b) Soft clothes of people absorb sound instead of reflecting it
c) Destructive interference of sound takes place
d) Excessive reverberations take place

Ans: d

Explanation: Echoes cannot be heard when the hall is full of people because of excessive reverberations.

4. Consider the following differences between bacteria and cyanobacteria:

1. While bacteria are prokaryotic organisms, cyanobacteria are eukaryotic organisms
2. Bacteria are comparatively smaller in size than cyanobacteria

Which of the above statements is/are correct?
a) Only 1 b) Only 2
c) Both 1 & 2
d) Neither 1 nor 2

Ans: b

Explanation: The first statement is incorrect because both bacteria and cyanobacteria are prokaryotic organisms.

 

5. Consider the following:

1. X-rays
2. Infrared rays
3. Radio waves
4. Gamma rays
5. Microwaves

Which among the following is the correct order of their increasing wavelength?
a) 1, 4, 2, 3, 5 b) 4, 1, 2, 5, 3
c) 4, 1, 5, 2, 3 d) 5, 4, 1, 2, 3

Ans: b

Explanation: (Gamma rays, X-rays, infra-red rays, microwaves, radio waves) Gamma rays: shorter than 0.1 Å X-rays: 0.1 Å to 100 Å Ultra-violet rays: 100 Å to 4000 Å visible light: 4000 Å to 8000 Å infrared radiation: 8000 Å to 3 × 107 Å microwaves: 3 × 107 Å to 1011 Å radio waves: 11 × 1011 Å and above.

 

6. In which of the following respects, the ultraviolet radiations are similar to white light?

1. Both obey the laws of reflection and refraction
2. Both travel with same speed in vacuum
3. Both are equally active chemically
4. Both are scattered equally

Select the correct option from the codes given below:

a) Only 1 b) Only 1 & 2
c) Only 1, 2 & 3 d) 1, 2, 3 & 4

Ans: b

Explanation: Both ultraviolet radiations and white light obey not only the laws of reflection but also the laws of refraction. Both travel with the speed of 3 × 108 ms–1. Ultraviolet waves get readily scattered as compared to visible light. Ultraviolet waves are chemically more active than white light.
Echoes cannot be heard when the hall is full of people because of excessive reverberations

K Aloke Kumar,
Director,
Telangana State
BC Study Circles