Explanation

The frequency of AC (Alternating Current) supply in Pakistan is typically 50 Hertz (Hz).

AC electricity alternates back and forth in a direction 50 times per second

Explanation

The correct preposition with "adjacent" is "to."

Correct sentence: "His house is adjacent to the mosque."

Explanation

Robert Koch established the germ theory of disease by demonstrating a causal relationship.

Between specific microorganisms and particular diseases, most notably with his research on anthrax.

Explanation

Clenched  "بھینچے ہوئے" (مثلاً دانت یا مٹھی سختی سے بند کرنا)

Clasped = مضبوطی سے پکڑا ہوا / بند کیا ہوا

Explanation

The correct phrase is "yelling at" when someone is shouting angrily toward someone.

Correct sentence: "She was yelling at her students."

Explanation

The phrase "brought up" means to raise or rear a child.

Correct sentence: "She was brought up by her uncle."

Explanation

Thermodynamics is the study of the relations between heat, work, temperature, and energy

Thermodynamics حرارت کے میکانکی حرکت میں بدل جانے کا عمل 

Explanation

In the novel "Goodbye, Mr. Chips" by James Hilton,
Mr. Chips becomes a teacher at the fictional English public (boarding) school called Brookfield.

Explanation

The correct preposition with "paid" when referring to something purchased is "for".

The sentence should be: "I have paid for it."

Explanation

Acetic acid is the main component of vinegar.

It is a liquid made by fermenting the natural sugars found in fruits, grains, and other food sources.

Vinegar is typically made from apples, grapes, or other fruits, and it contains approximately 4-6% acetic acid by volume.