Physics — Part 1 MCQs with Explanations

Stock value is not used in the field of physics.

Radiocarbon is produced in the atmosphere as result of collision between fast neutrons and nitrogen nuclei present in the atmosphere.

It is easier to roll a stone up a sloping road than to lift it vertical upwards because work done in rolling a stone is less than in lifting it.

The absorption of ink by blotting paper involves capillary action phenomenon because the blotting paper is a thin and a smooth paper which allows a little thicker liquids like ink to absorb.

Siphon is a tube bent to form two legs of unequal length by which a liquid can be transferred from a reservoir and then down to a lower level of it. Siphon will fail to work if, the level of the liquid in the two vessels are at the same height.

Large transformers, when used for some time, become very hot and are cooled by circulating oil. The heating of the transformer is due to both the heating effect of current and hysteresis loss.

Fermi - A unit of length equal to 10 -15 meter (one femtometer), used in nuclear physics. It is similar to the diameter of a proton.

Light year is a unit of distance.

Mirages happen when the ground is very hot and the air is cool. The hot ground warms a layer of air just above the ground. When the light moves through the cold air and into the layer of hot air it is refracted (bent). A layer of very warm air near the ground refracts the light from the sky nearly into a U-shaped bend.

The light from the sun takes about 8 minutes to reach the Earth after it has been emitted from the sun's surface.

The earth rotates from west to east.

Pa(Pascal) is the unit for pressure.

They are nearer to earth and hence we receive a greater amount of light.

Metals are good conductors of electricity because they contain free electrons.

When length of capillary tube is insufficient then we would observe no rise on level of water because their will be no air pressure created enough to rise the water level.

Impulse and moment of force.

Since the Force and the duration of time for which it acted are same, the product of force and time will be the same for both. Since Force×time gives change in momentum of a body, and they had 0 momentum initially, their final momenta will be same.

Pressure is a scalar quantity.

A rectifier is an electrical device that converts alternating current (AC), which periodically reverses direction, to direct current (DC), which flows in only one direction. The process is known as rectification, since it "straightens" the direction of current.

Out of the following neutrons is not emitted by radioactive substance.

Sound waves in air (and any fluid medium) are longitudinal waves because particles of the medium through which the sound is transported vibrate parallel to the direction that the sound wave moves. A vibrating string can create longitudinal waves as depicted in the animation below.

You see that the field lines near the center are parallel to the length of the bar. Moreover, the density of the field lines on the picture is maximized at the "poles" of the bar magnet and minimized at the center which means that the magnitude of the magnetic field is smallest at the center, too. It's not hard to see why the field lines look approximately as those on the picture above. For an infinitely long magnet, the magnetic field would be fully confined to the cylinder - think of an infinitely long solenoid which essentially has the same magnetic field as a bar magnet. For a bar magnet of a finite length, the field lines ultimately split behind the poles but they're still comparably strong over there. On the other hand, the field outside the bar, and far from the poles, is only nonzero because of some subleading effects; it would vanish for an infinitely long solenoid - that's why the field is so small over there.

In physics, friction is the force resisting the relative motion of solid surfaces, fluid layers, and material elements sliding against each other. When walking, the friction between the ground and the feet is crucial for maintaining stability and propulsion. Option A: While it's true that sand is soft and concrete is hard, the question is specifically asking about the difficulty of walking on each surface, which relates more to friction than hardness. Option B: Sand has a lower coefficient of friction compared to concrete. This means that there is less resistance between the feet and the sand, making it more difficult to walk on a sandy road as compared to a concrete road where the friction between the feet and concrete is greater, providing better traction and stability. Option C: This is the opposite of the correct explanation. If the friction between sand and feet were more than that between concrete and feet, walking on sand would be easier, not more difficult. Option D: The texture of the surfaces (grainy sand versus smooth concrete) might play a role in perception, but the primary factor affecting difficulty in walking is the friction between the surfaces and the feet, as explained in option B. Therefore, the correct answer is Option B: the friction between sand and feet is less than that between concrete and feet.

14 m/s is the correct answer to “Find the maximum velocity for the overturn of a car moving on a circular track of radius 100 m. The co-efficient of friction between the road and tyre is 0.2”. This question is standard in competitive examination syllabi for Physics.

The amplitude (A) is independent of other means it is not related to the other quantities.

The SI unit of intensity of illumination (illuminance) is the lux. An illuminance of 1.0 lux is produced by 1.0 lumen of light shining on an area of 1.0 m 2 .

On a rainy day, small oil films on water show brilliant colours. This is due to Interference. Interference is a phenomenon in which two waves superimpose to form a resultant wave of greater, lower or same amplitude.

Since we know that electric currents move from a higher potential or a lower potential. Also, electrons move in the direction opposite to electric current. So the electron on the line joining two points A and B will move from lower to higher potential i.e, it will move towards B.

The material of rain proof coats have the property of not minimizing the surface tension which will tend the water molecule to be in its drop form.

RADAR is used for detecting and locating the position of objects such as Aeroplanes.

Sound of frequency below 20 Hz is called Infrasonic.

On a clean glass plate a drop of water spreads to form a thin layer whereas a drop of mercury remains almost spherical because cohesion of mercury is greater than its adhesion with glass.

Suitable impurities are added to a semiconductor depending on its use. This is done in order to increase its electrical conductivity.

Stars twinkle because the refractive index of the different layers of the earth's atmosphere changes continuously.

It takes much longer to cook food in the hills than in the plains, because in the hills the atmospheric pressure is lower than that in the plains and therefore water boils at a temperature lower than 100 o C causing an increase in cooking time.

Moment of inertia is tensor.

Of the following natural phenomena, mirage is known in Sanskrit as 'deer's thirst'?

The air pressure in an aircraft (cabin pressure) is kept higher than the atmospheric pressure at high altitudes to avoid discomfort to passengers due to low outside air pressure. This pressure is called cabin pressurization. Hence the normal atmospheric pressure is maintained by the use of air pumps.

Increasing order of velocity of sound in the following media is as follows : Air, water and iron.

One thousand microns is equal to 10 -3 m.