Physics - MOST IMPORTANT Haryana PCS Previous Year Questions

Which of the following statements with reference to uniform linear motion and uniform circular motion is/are true?

1. In a uniform linear motion, a body moves in the same direction with a constant speed but in uniform circular motion, the speed of the body remains constant and the direction of the motion changes continuously.
2. In a uniform linear motion, there is instantaneous change in velocity but in uniform circular motion, the velocity remains the same.
3. A uniform linear motion is an accelerated motion but a uniform circular motion is not an accelerated motion.

Select the correct answer from the options given below:

Which of the following statement(s) about the freely falling objects is/are FALSE?

1. Freely falling objects are the objects falling from a height towards the earth under gravitational force of the earth.
2. The acceleration of a body falling freely towards the earth depends on the mass of the body.
3. If an object is dropped freely from a height, its initial velocity 'u' is zero and if an object is thrown vertically upwards, its final velocity 'v' becomes zero.

Which of the following does not involve Total Internal Reflection?

The best electrical conductor among the following is

The depth of a sea can be determined by using SONAR and consider the following statements about it:

1. It uses ultrasonic waves for measurement of depth of a sea.
2. The speed of ultrasonic waves in sea water is the same as that of sound in air.
3. Time taken by the ultrasonic waves reflected from the bottom of the sea to reach the detector is used to measure the depth.
   Which of the above statement(s) is/are correct?

Consider the following pairs:

1. Plane mirror: Image of the same size as the object
2. Concave mirror: Rear view mirror in a vehicle
3. Convex mirror: Dentist
   How many of the above pairs are correctly matched?