MP Police SI (Technical) Mock Test - 2 - MP Police SI MCQ

Alpha rays (α): Alpha ray, also called alpha particles alpha ray, contains two protons and two neutrons bound together into a particle just like a helium-4 nucleus.

Beta rays (β): Beta rays, also called beta particles or beta radiation, may be high-energy, high-speed electron or positron emitted by the radioactive decay of an atomic nucleus during the process of beta decay.

Gamma rays (γ): A gamma-ray, or gamma radiation, is penetrating electromagnetic radiation arising from the radioactive decay of atomic nuclei.

The ability of radiation to damage molecules is known as ionizing power.

The ability of each type of radiation to pass through matter is expressed in terms of penetration power.

We know radiation is caused because of radioactivity and the table below represents penetration power and ionization power of different radiation.

The conversion of a solid directly into vapors is called sublimation.

Sublimation: It is the conversion of a solid directly into vapors. Sublimation takes place when the boiling point is less than the melting point.

The heat required to change a unit mass of solid directly into vapors at a given temperature is called the heat of sublimation at that temperature.

Given,

As we know,

Where,

Power

Potential difference in the circuit

Resistance of the bulb

Resistance of the bulb

When

Power consumed

Thus, power is consumed by the bulb.

From momentum conservation

Now, K.E is conserved in an elastic collision,

Let the investment of is and investment of is .

Investment by

Ratio in which the profit would be shared

Since the share of Rs.

Total profit

Total profit = Rs.

Total profit is Rs.

According to the plum pudding model of the atom, the electrons are embedded in the distribution of positive charges.

The major limitations of the model are:

• According to this model, the positive charges are distributed over the volume of the atom and the electrons are embedded in it.
• Since the positive charges are distributed over a volume if the alpha particle comes nearby the nucleus it must be deflected.
• Instead of that in practice during the scattering, most of the alpha particles don't pass without deviation. Therefore, using this model the alpha particle scattering cannot be explained. Therefore, statement (i) is a limitation.
• Since most of the alpha particle passes without any deviation most part of the atom must be empty or the positive charges must be concentrated to a small volume (i.e., Nucleus ). This is contrary to the argument of the plum pudding model, which means the model wasn't able to account for the exact position of the nucleus. Therefore statement (ii) is a limitation.
• The model also fails to explain how the positive charges hold the negative charges. Therefore, statement (iii) is a limitation of the model.
• The electrons were invented by J. J. Thomson. The existence of electrons was earlier proved before this model. Therefore, statement (iii) is not related to the model.
• The only statements (i), (ii), and (iii) are limitations.

The fact that 'good absorbers of heat are good emitters' is based on Kirchoff's radiation law.

The Kirchoff's radiation law states that at a given temperature the coefficient of absorption of a body is equal to its coefficient of emission.

The resistivity does not change, if the shape of the resistor is changed. The resistivity depends on the nature of the material, the average relaxation time and the number of free electrons per unit volume.

The property of a conductor that opposes the flow of electric current through them and independent of the shape and size of the materials but depends on the nature and temperature of the materials is called resistivity.

Let and be the current due to the two cells.

Since the voltage across each resistor connected in parallel is the same,

Volatge across the first cell,

..(i)

Volatge across the second cell, ..(ii)

Total current,

Equation of emf of a cell,

Comparing (i) and (ii) we get,

When the source approaches the observer,

When the observer approaches the source,

Given:

Investment of Shubham = Rs. 2250

Time period of Shubham = 1 Year i.e. 12 Months

Investment of Rahul = Rs. 2500

Total Profit = Rs. 6050

Profit of Rahul = Rs. 2750

Profit of Shubham = 6050 – 2750 = Rs. 3300

Ratio of profit = 3300 : 2750

= 6 : 5

The Ratio of capital is equal to the ratio of profit. Then,

⇒ 2250 × 12 : 2500 × X = 6 : 5

⇒ 5(2250 × 12) = 6(2500 × X)

⇒ X = 9 months

∴ Rahul invested after 3 months.

PVC is a thermosetting plastic.

• Poly vinyl chloride (PVC) is a synthetic plastic polymer.
• Polyester is a polymer of the ester functional group.
  
• There are two types of polyesters from which thermoplastic or thermosetting plastics are made. The difference between these two types of polyester is their chemical structure.

Hund's rule:

• Every orbital in a sublevel is singly occupied before any orbital is doubly occupied.
• All of the electrons in singly occupied orbitals have the same spin (to maximize total spin).

According to Hund's rule we will fill the orbitals with a single electron then start filling it in both the spins.

That's why the electronic configuration of

Nitrogen is [He] 2s² 2px¹2py¹2pz¹

and not [He] 2s² 2px²2py¹2pz⁰.

As we know,

If a, b and c are three terms in GP then b² = ac and vice-versa

If three terms a, b, c are in HP, then b =  and vice-versa

When three terms are in AP, the middle one is called the arithmetic mean of the other two.

If a, b and c are three terms in AP then b =  and vice-versa

Given x, y, z are in G.P

y² = xz ....(1)

On multiply both sides by 9, we get

⇒ (3y)² = 9xz

Taking log on both sides, we get

⇒ 2In 3y = In 3x + In 3z

⇒ ln(3x), ln(3y), ln(3z) are in A.P

So, ln(3x), ln(3y), ln(3z) are in A.P

Statement 1 is correct.

Again taking eq(1)

y² = xz 

Taking log on both sides, we get

⇒ 2In y = In x + In z

On adding 2xyz on both the sides, we get

⇒ 2(xyz + In(y)) = (xyz + In(x)) + (xyz + In(z))

⇒ xyz + ln(x), xyz + ln(y), xyz + ln(z) are in A.P

 are in H.P

It means  xyz + ln(x), xyz + ln(y), xyz + ln(z) are not in HP.

Statement 2 is not correct.

Electric Heater is a device that can convert Electric energy into heat energy.

Any process in which electrical energy is converted into heat is called electro-heating.

An electric heater is a device that converts electrical energy into heat. In all types of electric heaters, the work of generating heat is done by electrical resistance, which provides heat by Joule heating.

Most of the modern electric heating devices use nichrome wire as the heater.

Beta particles have the same mass and charge as an electron have. A beta particle, sometimes called beta ray, , is a high-energy, high-speed electron or positron emitted in the radioactive decay of an atomic nucleus, such as a potassium-40 nucleus, in the process of beta decay. Two forms of beta decay, and , respectively produce electrons and positrons.

When a little mercury is drained off, the position of center of mass of the ball falls ( with respect to fixed end) so that the effective length of pendulum increases hence T increases. At first, Bob is filled up. Now as mercury is drained, the CM of Bob will go down and from the formula , Time period will be increase as length is increasing.

Now when the Mercury is about to drain off, CM will again shift to center of sphere and thus time period will decrease.

Hydrolysis is a chemical reaction where the water molecules are added to the compound undergoing the reaction.

During hydrolysis, the water molecule undergoes decomposition to give and ions respectively.

All the given options are examples of metal carbides.

Now, we know that carbides are compounds that have carbon and other elements which have less electronegative character than carbon atoms.

Metal carbides are compounds that have a transition metal ion and carbon atom as the constituents.

These structures are more of a complex type. Propyne is basically, .

is an ionic carbide and on hydrolysis with water yields magnesium hydroxide and propyne which is a three-carbon product.

is a metal carbide and on hydrolysis yields methane and aluminium hydroxide.

on hydrolysis gives boron oxide while carbon monoxide and hydrogen gases are evolved.

on hydrolysis gives lanthanum hydroxide and methane.

Thus, from the above chemical reactions, it is clear that is the correct option. As it gives propyne as a product.

Factors of and :

Common factors of and

HCF of and is .

Potential difference between A and B,

Potential difference between and ,

Potential difference between and ,

Biodegradable polymers are polymers which can be decomposed by bacteria.

Nylon 2-nylon 6 is a biodegradable polymer that can be formed by the monomers of glycine and aminocaproic acid.

• Meter bridge: Meter bridge is instruments based on the principle of Wheatstone bridge and is used to measure an unknown resistance.
• In the case of a meter bridge, the resistance wire AC is 100 cm long. Varying the position of tapping point B, the bridge is balanced.
• If in the balanced position of bridge 
  
• From above it clear that the meter bridge works on the principle of Wheatstone bridge. Therefore, option 1 is correct.
• The Meter Bridge is instruments based on the principle of Wheatstone bridge and is used to measure an unknown resistance. Therefore option 2 is correct.
• The Meter bridge can't measure the internal resistance of a battery.
• A potentiometer is a device used to measure the internal resistance of the battery. Therefore option 3 is incorrect.

Given,

Mass

Radius

Velocity

As we know,

The angular speed is given by,

Kinetic energy,

Vowels = 2, Consonants = 5, Total Alphabets = 7

Since 4 letter words must include 2 vowels, we don't need to select them, and the rest of the 2 letters will be taken from 5 consonants.

Number of ways of selecting 2 letters from 5 consonants = ⁵C₂ = 10

Arrangement of all 4 letters will be given by 4! = 24 ways

Total number of arrangements = ⁵C₂ × 4! = 10 × 24 = 240 ways

∴ The total number of words that can be formed is 240.

The human eyes form the image of an object at its Retina.

• The screen of the eye on which the image is formed is known as retina.
• The image formed on the retina of the human eye is real and inverted.

The conventional sources of energy are non-renewable energy sources which are being used extensively in a way that their known reserves have been depleted to a great extent. These include wood, coal, petrol and diesel.

Bohr’s Model: Niels Bohr by making 4 postulates solved the puzzle of hydrogen spectra.

• The electrons revolve around the nucleus in circular orbits.
• The radius around the orbit has some special values of radius. In these stationary orbits they do not radiate energy as expected from Maxwell’s laws.
• Energy of each stationary orbits are fixed, electrons can jump from a higher orbit to lower orbit by emitting a photon of radiation. Where Higher energy orbit – Lower energy orbit = (h c)/λ

Electron can also jump from lower to higher energy by absorbing energy.

• In stationary orbits, the angular momentum L of an electron is an integral multiple of (h/2π)

L = n × (h/2π)

Limitations of Bohr’s Model:

It could not work for atoms and ions having more than one electron not even for Helium.

Since Bohr’s Model is applicable for atoms and ions having one electron.

Be – 4 electrons

He⁺ - 1 electron, this is more suitable for Bohr’s model explanation.

Li⁺ - 2 electrons

Li – 3 electrons

The polyacrylonitrile is a polymer of acrylonitrile. It is formed from addition reactions of acrylonitrile in the presence of peroxide as catalyst. The monomer is acrylonitrile. Thus, its commercial name is acrilan or orlon.

The phase is the angle made by the particle.

The smallest interval of time after which the motion is repeated is called a period.

The reciprocal of the smallest interval of time after which the motion is repeated is its frequency.