Practice Set 9 - general science mcq Online Quiz (set-1) For All Competitive Exams

Q-1)   The simple harmonic motion of a particle is given by y = 3 sinω + 4 cosω. Which one of the following is the amplitude of this motion?

(a)

(b)

(c)

(d)

Explanation:

Q-2)   A thunder clap is heard 5.5 second after the lightening flash. The distance of the flash is (velocity of sound in air = 330 m/s)

(a)

(b)

(c)

(d)

Q-3)   The fine powder of a coloured glass is seen as

(a)

(b)

(c)

(d)

Explanation:

All colours are reflected.

Q-4)   In human eye, image of object forms at

(a)

(b)

(c)

(d)

Q-5)   Consider the following statements with reference to observations made by an astronaut on the surface of moon:
  1. The astronaut finds that a simple pendulum continues to oscillate for a much longer time, than that on the earth.
  2. No atmosphere exists there.
Which of the statements given above is/are correct ?

(a)

(b)

(c)

(d)

Q-6)   Suppose a rocketship is proceeding from the Earth at a speed of 2/10th the velocity of light. A light in the rocketship appears blue to the passengers on the ship. What colour would it appear to an observer on the Earth?

(a)

(b)

(c)

(d)

Q-7)   If a liquid is heated in condition of weightlessness, the heat is transmitted through

(a)

(b)

(c)

(d)

Explanation:

Convection is not possible in weightlessness. So the liquid will be heated through conduction.

Q-8)   Material A has a critical angle $i_A$, and material B has a critical angle $i_B$ ($i_B > i_A$). Then which of the following is true?
  1. Light can be totally internally reflected when it passes from B to A
  2. Light can be totally internally reflected when it passes from A to B
  3. Critical angle for total internal reflection is $i_B – i_A$
  4. Critical angle between A and B is $sin^{-1}({sini_A}/{sini_B})$

(a)

(b)

(c)

(d)

Explanation:

iB > iA or  sin-1 $(1/{µ_B})$ > sin-1 $(1/{µ_A})$ or µA > µB

Hence medium A is denser and B is rarer.

Total internal Reflection: When the object is placed in an optically denser medium. and if the incident angle is greater than the critical angle then the ray of light gets reflected back to the originating medium.

For critical angle (α) from medium A to B, ${_Bµ_A}$

${_Bµ_A}$ = $1/{sin α}$ or sin α = $1/{_Bµ_A}$ = ${µ_B}/{µ_A}$

⇒ sin α = $1/{sin i_B}$ x ${sin i_A}/1$

⇒ α = sin-1 $[{sin i_A}/{sin i_B}]$

Q-9)   Heat travels through vacuum by

(a)

(b)

(c)

(d)

Explanation:

Heat radiations are electromagnetic waves of high wavelength.

Q-10)   The velocity of sound in air is approximately

(a)

(b)

(c)

(d)