MHT CET Mock Test - 3 - JEE MCQ

Here we are using the formula
current = neAv ...............(1)
 where n= number of electron density
A =area of cross section
e= charge of electron
v=drift velocity
As both the wires are of the same materials then the electron density is the same for both.
For the first wire, current I is given by,  
I = neAv  
 Now according to the problem another wire of half the radius and of the same material when the drift velocity is 2v
Therefore for the second wire current is = ne(A/4)(2v)
                                                                = (neAv)/2
                                                          now putting I at this place
= I/2
 

Explanation:An intrinsic semiconductor, also called an undoped semiconductor or i-type semiconductor, is a pure semiconductor without any significant dopant species present. The number of charge carriers is therefore determined by the properties of the material itself instead of the amount of impurities. In intrinsic semiconductors the number of excited electrons and the number of holes are equal: n = p.

As, U=−Gm₁m₂/r, 
it can be used to describe the potential energy in a system of point charges (or radially symmetric spheres) as a function of their separation distance r, then the maximum value is zero at infinite separation.
Hence, its maximum value is zero at infinity.
 

As magnetic field lines due to current carrying wire is along the surface and hence,
ϕ=B.A=BAcos90^O=0

We know, a piece of copper is a metal while that of germanium is a semiconducting material. For metals resistance increases with increase in temperature. The semiconductor has a negative temperature coefficient of resistance. Hence, when it is cooled its resistance increases.

Photoelectric effect can be explained by assuming light consisting of quanta that when a photon of certain energy falls on the surface of metal, then the metal surface starts to emit an electron known as photo electrons.

 As per the question, rays are falling on the mirror, which cleared that Regular reflection is taking place.
So, As per the laws of regular reflection.
=> ∠incident= ∠reflection
∠incident= ∠reflection=38A^o
Also we know that normal is at 90°to the mirror.
Now, to get the required angle we need to reduce angle of reflection from normal.
=>90A^o-38A^o=52A^o
so, the correct answer is option B.

NOTE : Electr o mag n et sh ould be amen abl e to magnetisation &  demagnetization.

∴ retentivity should be low & coercivity should be low

The magnetic field at a point on the axis of a circular loop at a distance x from centre is,

Gun metal is an alloy of Cu, Zn and Sn. It contains 88% Cu 10% Sn and 2% Zn.

The correct answer is option A

Hypophosphorous acid when treated with diazonium salts is reduced to arenes.
ArN₂Cl + H₃PO₂ + H₂O ⟶ ArH + N₂ + H₃PO₃ +HCl

Epoxide undergo nucleophilic attack of NH₃ at less substituted α-carbon giving anti hydroxy amine.

β-H at the bridging carbon is anti to leaving group,lost in E2 reaction.

The correct answer is Option C.

Lyophobic colloid is a colloidal dispersion whereby the dispersed phase is solvent hating .i.e little interaction between the dispersed phase and the continuous phase. Lyophobic colloidal particles are not readily solvated because the continuous phase prefers to interact with one another rather than be involved in solvating the dispersed particles. 
Casein (a milk protein), a lyophobic colloid present in milk acts as an emulsifying agent as it forms a protective layer around fat molecules dispersed in water. It is found in milk as a suspension of particles called "casein micelles" which show only limited resemblance with surfactant-type micelle in a sense that the hydrophilic parts reside at the surface and they are spherical.
 

An α-βC—C bond is always formed in aidol reaction .

Nucleophilic addition at carbonyl carbon of cyclopropane releases angle strain.

β-H, anti to Br at more substituted β-carbon is lost to give more stable alkene.

Sucrose or cane sugar is the commonest of the disaccharides. It has the molecular formula C₁₂H₂₂O₁₁. It does not form a phenylhydrazone or exhibit carbonyl properties. On hydrolysis with dilute acids, it yields one molecule of D-(+)-glucose and one molecule of D-(—)-fructose. It is not a reducing sugar. 

Non metallic oxides are acidic.

• Natural polymers abound Proteins, starches, carbohydrates, even DNA are natural polymers.

• A hamburger consists mostly of polymers. The cardboard container the hamburger came in and the napkin used to wipe up any ketchup spills are also made of polymers.
• Understanding natural polymers' structure, characteristics and uses can help people make environmentally conscious and informed choices. 

Since g(x) and h(x) are integrals of the same function , therefore ; g(x) – h(x) is constant.

 Length of perpendicular from (2,3,-5) to the plane x + 2y − 2z − 9 = 0.
= |(2 + 2×3 −2×(−5) − 9)|√1² + 2² + (−2)²
= |2 + 6 + 10 − 9|/√9
= 9/3
= 3 units.

The given curves are : (i) y = x – 1 , x > 1 . (ii) y = - (x – 1) , x < 1. (iii) y = 1 these three lines enclose a triangle whose area is : 1/2 .base.height = 1/2 .2 .1 = 1 sq. unit.

Variance = 15 
New variance = 2^2*15 
= 4*15 
= 60

We have , 

Therefore, range of f(x) is {-1}.

Acceleration is the derivative of velocity, so we integrate a(t) to get v(t):

v(t)=∫a(t)dt=∫sin(t)dt=−cos(t)+C

Now, we are given that the velocity at t=0 is 10 km/hr. We can use this information to find the constant C:

v(0)=−cos(0)+C=−1+C=10

Solving for C, we get C=11.

Now, we have the velocity function:

v(t)=−cos(t)+11

Finally, we integrate v(t) to get the displacement function s(t):

s(t)=∫v(t)dt=∫(−cos(t)+11)dt

s(t)=−sin(t)+11t+D

Now, we need to find the constant D. We are given that the car moves from t=0 to t=π/2, and we know that s(0)=0 (starting position). Plugging in these values, we can solve for D:

s(0)=−sin(0)+11(0)+D=0

D=0

So, the displacement function is:

s(t)=−sin(t)+11t

Now, to find the distance traveled, we evaluate s(t) over the given time interval:

Distance=s(π/2​)−s(0)

Distance=(−sin(π/2​)+11(π/2​))−(−sin(0)+11(0))

Distance=−1+11π​/2 = 16.27887 kilometers

Therefore, the distance traveled by the car from t=0 to t=π/2​ is 16.27887 kilometers​.