MP Police SI (Technical) Mock Test - 10 - MP Police SI MCQ

Here,

Let event of getting at least two heads

Carbon tetrachloride on heating with ethanolic KOH gets hydrolyzed to form potassium chloride and potassium carbonate.

Heat is supplied to the system by an electric heater at a rate of .

Thus, heat supplied,

The system operates at a rate of .

Clearly, work done,

Using the first law of thermodynamics,

where,

internal energy

In the presence of oxygen, the filament of the light bulb would burn up as a result of the high temperature. So the vacuum is maintained in the light bulb. Since there is no medium present in the light bulb, so the heat transfer takes place by radiation because the conduction and the convection require a material medium to transfer heat.

We write for 'head' and for 'tail'. When two coins are tossed simultaneously, the possible outcomes are , which are all equally likely. Here ) means head up on the first coin (say on ₹ ) and head up on the second coin (₹. Similarly means head up on the first coin and tail up on the second coin and so on.

The outcomes favourable to the event , 'at least one head' are and .

So, the number of outcomes favourable to is .

Therefore,

i.e., the probability that Harpreet gets at least one head is .

You can also find as follows:

Given:

(x + 1)² - 1 = 0

⇒ x² + 2x + 1 - 1 = 0

⇒ x² + 2x = 0

⇒ x (x + 2) = 0

∴ x = 0 or -2

So, both roots are real.

Given,

Human temperature = 60°C

The following mathematical formula represents the conversion from Fahrenheit to Celsius:

⇒ 

⇒ 

⇒ °F

Assume

For ' ' to be maximum , to be minimum

As,

Now, For to be minimum

Formation of photochemical smog:

• There are various types of oxides of nitrogen present in the atmosphere.
• When UV rays fall on these oxides, they undergo photolysis to give nitric oxide and nascent oxygen.
• The atomic oxygen radicals then react with oxygen to form ozone.
• Atomic oxygen also reacts with hydrocarbons present to form highly reactive free radicals of hydrocarbons.
• Hydrocarbon free radicals react further with species like to give PAN, aldehydes, ketones, and smog components.
• All the compounds ozone, aldehyde ketones and PAN- peroxyactetyl nitrate are constituents of smog.

Ozone so formed oxidise to

ketones, etc.

So, the compound which is not present in photochemical smog is CFCs- chlorofluro carbons.

'The rate of cooling of an object is directly proportional to the temperature difference between the object and the medium around it' - This is Newton's law of cooling. According to Newton's law of cooling, the rate of heat loss of a body is proportional to the difference between the temperature of that body and the temperature of the medium around it. In other words, this law states that the value of 'coefficient of heat transfer' remains constant.

Thermal equilibrium implies equality of temperature which depends upon the average molecular kinetic energy.

In benzyl amine the lone pair of nitrogen is not in conjugation with the benzene ring and it is free for donation to an electrophile. So, D is the most basic compound.

In -nitroaniline, acetanilide and aniline, the lone pair of nitrogen is in conjugation with the aromatic system (benzene ring). So, it is delocalized and is not freely available for donation. So, and are less basic.

Friction is a force that opposes the relative tangential motion between two planes. The value of the force of friction depends on the force normal between the two planes. There are two types of friction: static friction and kinetic friction.

I. x² = 841

⇒ x = +29, -29

II. y² – 15y – 76 = 0

⇒ y² + 4y – 19y – 76 = 0

⇒ (y – 19)(y + 4)

So, y = 19, y = -4

Comparison between x and y (via tabulation):

∴ Relationship between x and y cannot be established.

Glucose and fructose give positive Tollen's test.

The Tollen's test gives positive results only when aldehyde and hydroxy ketone is present. Glucose contains an aldehyde group on top so glucose gives a positive test, and fructose contains a hydroxy ketone. The Tollen's reagent oxidises the aldehyde or hydroxy ketone and the silver ions are reduced to metallic forms which get deposited on the sides of the test tube.

, , ? at which


(i) At the reaction is in equilibrium., (ii) At temperature below
, the reaction in the forward direction is non-spontaneous. In other words the reaction occurs in the backward direction.

Given:

Ratio of the incomes of A and B

Ratio of the savings of A and B

Income of A Savings of B

As we know,

Income Expenditure Savings

Income Savings Expenditure

Let the income of A and B be and

And their savings be and

According to question

Expenditure Income Savings

Expenditure A: Expenditure B =

Expenditure A: Expenditure B

Expenditure A: Expenditure B

Multiplying in denominator and numerator,

The unit of power is the watt, and hence the unit of energy is watt-second since energy is the product of power and time.

The watt-second is referred to as joules. One watt-second is equal to of a watt-hour or one joule. The dimensions of energy are which is the same as work. The SI unit joule (J) is named after the famous British physicist James Prescott Joule.

So, from the above points, we can clearly infer that Watt second is the unit of energy.

The catalyst used is platinum. The catalyst glows since the catalytic oxidation of ammonia is an exothermic reaction.

Given:

Temperature

Temperature in Kelvin Temperature in

Temperature in Kelvin

As one root of the equation is

We know that the level of liquid increases remains the same or becomes down. On account of the coefficient of cubical expansion of liquid is more, equal and less than the cubical expansion of the metal of container. Thus, when liquid is heated, it will overflow so that cubical expansion will be greater than .

The gas thermometers are more sensitive than liquid thermometers because gases expand more than liquids for a small rise in temperature, which will give better sensitivity in temperature measurement.

Clearly, there are cards, out of which there are face cards jack, queens, and kings.

getting a face card

Given,

Quadratic equation is

Discriminant

means two real and both are identical roots.

Compare with standard form

Discriminant

For real and equal roots, .

Isothermal dissipation of work and adiabatic dissipation of work exhibit external mechanical Irreversibility.

In the isothermal compression of a gas there is work done on the system to decrease the volume and increase the pressure. The work done in adiabatic process derivation can be derived from the first law of thermodynamics relating to the change in internal energy to the work done by the system and the heat added to it. The work done for the change in volume by is given as .

Reduction of nitroalkanes yields amines, as shown in below reaction.

'Good emitters are good absorbers' This is Kirchhoff's law. According to the law, the emissivity and absorption capacity of all substances for a given temperature and wavelength is the same and is equal to the emissivity of a complete black body at the same temperature and wavelength.