Question : The colour of the ocean appears to be blue because the sunlight falling on it is:

Option 1: reflected

Option 2: refracted

Option 3: diffracted

Option 4: scattered

Question : In a coloured picture of blue and yellow colours, blue and yellow colours are used in the ratio of 4 : 3, respectively. If in the upper half, blue : yellow is 2 : 3, then in the lower half, blue : yellow is:

Option 1: $1:1$

Option 2: $2:1$

Option 3: $26:9$

Option 4: $9:26$

Question : The purpose of an optical filter is to___________.

Option 1: reflect lights of different colours

Option 2: dispense light into component colours

Option 3: refract the light of different colours

Option 4: transmit or absorb light of different colours

Question : If $a^{3}+\frac{1}{a^{3}}=2$, then the value of $\frac{a^{2}+1}{a}$ is ($a$ is a positive number):

Option 1: 1

Option 2: 2

Option 3: 3

Option 4: 4

Question : If $(a+\frac{1}{a})^2=3$, the value of $(a^3+\frac{1}{a^3})$ is:

Option 1: $0$

Option 2: $3(a+\frac{1}{a})$

Option 3: $3(a^2+\frac{1}{a^2})$

Option 4: $1$