Physics - MOST IMPORTANT UPSC EPFO Previous Year Questions
Practice real questions from previous year exams of UPSC EPFO.
The device to convert alternating current into direct current is
Assertion (A): A bus and a car (with lower weight than that of the bus) moving at the same velocity, are brought to rest on a level road by applying brakes which exert same retarding force. The car will travel lesser distance before coming to rest.
Reason (R): The kinetic energy to be destroyed is equal to the work done by the retarding force.
Assertion (A): A train has come out of the platform and is accelerating. If a person sitting in the train and facing engine, throws up a coin, it will fall ahead of him.
Reason (R): A force acts on the coin whose magnitude is equal to the product of the mass of the coin and acceleration of the train.
Which one of the following is a super-cooled liquid?
Which one of the following causes small air bubbles in water, which is stored in a glass vessel, to appear to shine with a silvery luster?
Weight of a body on the surface of the earth is W₁. The weight of the same body is W₂, at a height of 500 metres above the surface, and W₃ at a depth of 500 metres below the surface of the earth. Which one of the following is the correct relation?
Which one of the following is the correct statement?
Directions: This item consists of two statements, one labeled as the 'Statement (I)' and the other as 'Statement (II)'. You are to examine these two statements carefully and select the answers to these items using the codes given below:
Statement (I): In order to produce electric power from a geothermal reservoir, temperature above 180° is required.
Statement (II): To drive steam turbines, high temperature steam is used.
If the electrical resistance of a typical substance suddenly drops to zero, then the substance is called :
The material used for electric fuse is an alloy of tin and lead. This alloy should have:
A train travels at a certain average speed for a distance of 63 km. Thereafter it travels a distance of 72 km with an average speed of 6 km/hour more than the original speed. Total time taken to complete the journey is 3 hours. What is the original average speed of the train?
A 60 m long train travels at a uniform speed of 72 km/hour. It passes non-stop along the 600 m platform of a wayside station. What is the elapsed time for the train to entirely clear the platform?
Train A is 75 m long and travels at a uniform speed of 54 km/hour. Train B is 125 m long and travels at a uniform speed of 36 km/hour in the direction opposite to that of Train A. If these trains are crossing at a double track stretch, what is the time taken for the two trains to fully clear each other?
Which lamp has the highest energy efficiency ?
Yellow light is a combination of ________ primary colors.
Diverging lens produces ________ type of images.
The 5th state of matter is :
Speed of Blue color light in vacuum is :
In which direction does rainbow appear in the morning ?
God's particle is the pseudonym of ________