MHT CET Mock Test - 3 - JEE MCQ

It should be thrown with a velocity greater than or equal to escape velocity of the planet only then it will not return to Earth
Escape Velocity = √(2GM/R) = (2GM/R)^1/2 
Hence A is the correct answer.

The images of clouds and trees in water are always less bright than in reality because only a portion of the incident light is reflected and quite a large portion goes mid water.

Velocity of efflux when the hole is at depth h, v = √(2gh).
Rate of flow of water from square hole

Rate of flow of water from circular hole

According to problem

 

• When a source of white light is used instead of a monochromatic source, the diffracted image of the slit gets dispersed into constituent colours of white light.
• The central maximum will be white and on either side of the central maximum, there will be coloured fringes.

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.

When a light wave is reflected from an object , it changes not only it's amplitude but also its phase according to the properties of the object at a particular point. 
Therefore, option A is the right answer.

Explanation:Due to heating, when a free electron is produced then simultaneously a hole is also produced.

In Thomson’s plum pudding model, the positive charge is spread out uniformly across the atom, so α-particles passing through would experience only very small, gentle deflections, leading to a small average angle of deflection.

In contrast, Rutherford’s nuclear model postulates a dense, positively charged nucleus. While most α-particles pass through undeflected, a small number undergo large-angle scattering, which increases the overall average deflection angle.

Therefore, the average angle of deflection predicted by Thomson’s model is less than that predicted by Rutherford’s model.

Actually, diffraction occurs all the time. But when the aperture/wavelength ratio is large, the spacing between fringes becomes too small, and the diffractive effects are unnoticeable.

 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.

Q-factor: In LCR Circuit, the ratio of resonance frequency to the difference of its neighbouring frequencies so that their corresponding current is 1/√2​ times of the peak value, is called Q-factor of the circuit.
Formula: Q=(1/R)​ √(L/C)​​
So, Q ∝1/R
Conditions for the large value of Q factor:
(i) Value of CL​ should be large.
(ii) Value of R should be less.
 

Electrostatics means charges at rest, or relatively at rest so this force can be applicable only when charge produce electric field which is constant which is possible only when charges at rest or relatively at rest.

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

Maltose can be produced from starch by hydrolysis in the presence of the enzyme diastase. It can be broken down into two glucose molecules by hydrolysis. In living organisms, the enzyme maltase can achieve this very rapidly. In the laboratory, heating with a strong acid for several minutes will produce the same result.

• Drugs that mimic the natural messenger by switching on the receptor, are called agonists.
• These are useful when there is a lack of natural chemical messenger.
• Examples: oxycodone, methadone, hydrocodone, morphine, opium and others.

Bond length and (EN) oppose each other, with the larger halogens having longer bonds but weaker (EN). Thus CH₃CI > CH₃F > CH₃Br.

Decron is a condensation polymer. It is formed by the condensation of ethylene glycol and terephthalic acid. 

In a given structure there are 4 -pi bonds.Hence, total number of pi electrons are 8.

The given point is P(0,0,0) and the given line is 3x+2y-6z-21=0
Let d be the length of the perpendicular from P(0,0) to the line 3x+2y-6z-21=0
Then, d= |3*0 + 2*0 + (-6)*0 -21|/[(3)^2 + (2)² + (-6)²]^1/2
= |-21|/7
= 3

For 1 element not to be present in P∩Q possibilities for n element ⇒ Total
No. of fovourable cases = 3ⁿ

 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.

For every square matrix (A – A’) is always skew – symmetric.

3 × tan (x – 15) = tan (x + 15)
⇒ tan(x + 15) / tan(x – 15) = 3/1

► {tan (x + 15) + tan (x – 15)} / {tan (x + 15) – tan (x – 15)} = (3 + 1) / (3 – 1)

► {tan (x + 15) + tan (x – 15)} / {tan (x + 15) – tan (x – 15)} = 2

sin(x + 15 + x – 15) / sin(x + 15 – x + 15) = 2
sin 2x / sin 30 = 2
sin 2x / (1/2) = 2
2 × sin 2x = 2
Sin 2x = 1

∴ Sin 2x = Sin 90
2x = 90
x = 45

Number of sides of a cube = 6
Number of colour of a cube = 6
Number of ways of colouring =?
Consider a cube in 3D space 
Each of the sides towards East West North South and remaning two up and down 
Now fixing up positions down is also fixed 
Total number of ways 
= 6!/(4×6)
​= 5×3×2 
= 30 Ways
Hence, the correct answer is 30 Ways