Explanation

• The critical angle is the angle of incidence at which the angle of refraction is 90°, and beyond which total internal reflection occurs.
• This concept is crucial in understanding optical phenomena like fiber optics and prisms.

Explanation

Passage

Last night I was reading a book about the scientific inventions and discoveries made by the scientists in the last one hundred years. These inventions include radio, TV, telephone, electricity, jet engines, rockets, aeroplanes, tanks, atom bomb, computer and the conkest of the moon. I wondered what the world will look like before one hundred years. With these thoughts in mind, I went to sleep and found myself in the world of dreams.

I enters a new world. It was full of shining stars and planets. Their was also many spaceships. They were travelling from one planet for another, and from star to star. They had artificial of cylinders oxygen. I happened to visit Jupiter, the Mars, the Saturn, Uranus and the Pluto. Many human beings were settled on these planets. They had been living on those planets with the help of many electronic machines.

1. These inventions include radio, TV, telephone, electricity, jet engines, rockets, aeroplanes, tanks, atom bomb, computer and the _____ of the moon.

Conquest

2. I wondered what the world will look like _____ one hundred years.

After

3. I _____ a new world.

Entered

4. _____ also many spaceships.

There were

5. They were traveling from one planet _____ another, and from star to star.

To

6. The correct form of the sentence: They had artificial of cylinders oxygen is _____?

They had cylinders of artificial oxygen.

Explanation

"Those" refers to "the streets (of Lahore)" mentioned earlier.

It is a demonstrative pronoun used to point out specific things.

Explanation

Explanation

 A convex lens is thicker at the centre than at the edges. 

A camera uses a convex lens to focus light rays and form an image on a piece of film or a digital sensor at the back, capturing the scene in front of it.

Explanation

The Subtropical Continental Plateau lies in the western part of Balochistan, Pakistan.

It features dry climate, rugged terrain, and sparse vegetation.

Explanation

The process in which numbers are assigned to a person's performance is called Measurement

 Measurement refers to the act of assigning numerical values to specific traits or characteristics of an individual, based on a defined set of rules or criteria. 

Explanation

• The Moon is a non-luminous object because it does not produce its own light.
• Instead, it reflects the light of the Sun.

Explanation

مہاراجہ ایک اسم مکبر ہے کیونکہ یہ کسی شخص کی عظمت یا بزرگی کو ظاہر کرتا ہے۔

اسم مکبر ایسے الفاظ ہوتے ہیں جو کسی فرد یا چیز کی اہمیت یا شان کو بڑھا چڑھا کر بیان کرتے ہیں۔

Explanation

My friend tells me that I am not going to be punished.

In indirect speech, "says to" changes to "tells."

The present continuous tense ("are going") remains unchanged in indirect speech.