HPSC PGT Physics Mock Test - 4 - HPSC TGT/PGT MCQ

Key Points

Rock cycle:​​

• Rocks do not remain in their original form for a long period.
• They undergo a transformation.
• This cycle is an uninterrupted process through which old rocks are converted into new ones.
• Igneous rocks are primary rocks.
• These rocks can be changed into metamorphic rocks.
• Sedimentary and metamorphic rocks are formed from these primary rocks.
• The fragments evolved out of metamorphic rocks and igneous again form into sedimentary rocks.
• Sedimentary rocks themselves can develop into fragments.
• The crustal rocks -igneous, metamorphic, and sedimentary-once formed may be carried down into the interior of the Earth through subduction.
• In this process, parts or entire crustal plates subduct under another plate and the same melt at high temperatures in the interior.
• This results in the formation of molten magma, the unique source for igneous rocks.
• The process of transformation follows the steps,  'Igneous rocks - sediment - sedimentary rocks - metamorphic rocks - magma'​ 
• The image below clearly explains the rock cycle.

Hence, rock cycle is the process of transformation of rock from one to another

The correct answer is Prevent stubble burning.

Key Points

• The Supreme Court had appointed Justice Madan B. Lokur committee in October 2020, to prevent stubble burning in the states of Punjab, Haryana and Uttar Pradesh, amid rising levels of pollution in the national capital and adjoining regions.
  • ​Hence, option 2 is correct.
• He is a former judge of the Supreme court. 
• The Supreme Court also directed the appointment of the Environment Pollution Control Authority (EPCA).
• Chief secretaries of Haryana, Punjab and Uttar Pradesh were advised to help the Lokur panel with physical surveillance of fields to check instances of stubble burning and other related matters.
• It will get assistance from National Cadet Corps (NCC), National Service Scheme and Bharat Scouts.

The logic follows here is:-

1st and 3rd letters are interchanged.

4th and 6th letters are interchanged.

And 2nd letter is placed as it is.

Similarly,

Hence, the correct answer is "TNMFED".

in time   first function completes one oscillation, second function two oscillations and the third three

so for the combination T = 2π/ω

As we know,
the formula for energy of photon in terms of wavelength is,, E = hc/ λ
where, E = energy of photon
h = Planck's constant =
= 6.63×10^-34 Js
c = speed of light
= 3×10⁸ m/s
and lambda = wavelength
so,
E = [6.63×10^-34 J. s×3×10⁸ m/s]/5500×10^-10m
= [0.36×10^-26]/10^-8
= 0.36×10^-18
= 3.6×10^-19 J
Or, 2.26ev
 

Wavelength of light used is inversely proportional to number of fringes observed.

Explanation:In the first half of the cycle, power is supplied to the inductive circuit. In the next half the inductor dissipates the energy supplied by circuit.Thus overall no power is supplied to the circuit

In stationary position, spring balance reading  => mg = 49

Resistance of a wire of length l and cross-sectional area A is given by R=ρl/A​
here, x=ρ(4a)​/(2a×a)= 2ρ/a​ ;
y=ρ(a)​/ 2a×4a=ρ/8a​ and
z= ρ(2a)/4a×a​=ρ/2a​
thus, x>z>y

Concept:

Central force:

• The central force in classical mechanics is defined as the force that is acting on an object which is directed along the line joining the object and the origin.
• The magnitude of the central force depends only on the distance of the object and the centre.
• Due to the central force, the body moves or tends to move in a circular or an elliptical orbit around an axis.
• Since there is no torque due to the central force. So, the angular momentum will remain constant.
• Some example of central forces is gravitational force and electrostatic force.

Explanation:

Let, r represents the distance of the particle from origin and r̂ is radial direction, than central force

F(r) = F(r)r̂ 

So the torque acting on it

τ = r × F(r)r̂

⇒ τ = r × F = F(r) (r × r)

⇒ τ = 0    ......(1)

Let p = mv = linear momentum,

Now we know that momentum is also conserved in this case, therefore

Angular momentum L = r × P

r.L = r.(r × p)  = 0     ......(2)

Also, to know angle b/w velocity and angular momentum

v.L = v.(r × p) = 0    .....(3)

Hence, from equation (2) and (3), we can see that both the position vector r  and the velocity vector v  thus lie in the plane perpendicular to  L.

Therefore, we can say that, if a particle moving under a central force, its motion will be in phase.

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 we know,
Average power in ac circuit is given by P=V_rms​i_rms​cosϕ 
For pure capacitive circuit ϕ=90^o so P=0

Hg expands on heat (thermometers) it acts as a good conducting metal.

When liquid molecules are attracted strongly to themselves and weakly to those of solids, it costs lots of energy to create liquid-solid surface and liquid then does not wet the solid.

For Example: Mercury molecules (which make an obtuse angle with glass) have a strong force of attraction between themselves and a weak force of attraction toward solids. Hence, they tend to form drops.
On the other hand, water molecules make acute angles with glass. They have a weak force of attraction between themselves and a strong force of attraction toward solids. Hence, they tend to spread out.

Torque is the rate of change of angular momentum. Force in linear motion corresponds to torque in rotary motion. Thus, just as Newton’s second law can be written as F = dP/dt (F for linear motion), it can be written as T = dL/dt for rotary motion.

The angle suspended by the finite line charge at P=60°
So, the resultant electric field due to line charge will be at 60/2⇒30° since we can assume the charge concentrated at the centre of finite line charge.

Given,
We are given the current I=1.5Am where the wire will break.
We are asked to determine the root mean square of the current Irms. The maximum current here represents the current that just after it the wire will break. The maximum value of the current is the amplitude of the current wave and it should be larger than the root mean square of the current. Using equation, we can get the I_rms in the form,
I_rms = I_max/√2
The term, 1/√2, times any factor represents the root mean square of this factor, Now, plug the value for Imax into equation 1 and get I_rms
I_rms=I_max/√2
     =1.5A/√2
     =1.06A.

When two forces of equal magnitude opposite in direction and acting along parallel straight lines, then they are said to form a couple. The perpendicular distance between the two force forming a couple is called the arm of the couple.

Explanation:if a ball is thrown upward at an angle? The ball has a vertical and a horizontal component of velocity. The force of gravity is acting on it and its acceleration is in the downward direction. The vertical component of velocity is therefore changing. As the motion and acceleration is in opposite direction so vertical component of velocity decrease.

The smallest value that can be measured by the measuring instrument is called its least count.

Measured values are good only up to this value. The least count error is the error associated with the resolution of the instrument.

We know that the force of gravitation is inversely proportional to square of the distance between the two bodies,

i.e. F∝ r^-2

Hence, when the distance between them will be doubled, the force will be reduced by 4 times

So, the ratio will be 4:1

I = mr², therefore it depends on body mass and its mass distribution.
 

ϕ=6t²−5t+1
e= dϕ​/dt =12t−5
at t=0.25sec
∣e∣=(12/4−5)=∣3−5∣=2
i=e/R=2/10=0.2A

 Answer :- 

Solution :- torque when =180°

= 1.5 × 0.22 × sin 180°

= 0.33 × 0 = 0 Nm

Velocity of efflux 

Find ‘h’ to have range of ejected water ≥ x x 

Both the objects with different masses will attain the same v when striking the ground because acceleration and height is the same. 
As, K.E=(1​/2)mv²P.E=−GMm​p/r=mv
Thus K.E, P.E, and p will be different.
 

The multiplication of the numbers:
10.610 × 0.210 = 2.2281

Since, the numbers 10.610 and 0.210 have 5 and 3 significant digits, respectively. So, the final result must also have 3 significant digits.

The final answer is 2.23 after rounding off 2.2281. 

In a uniformly charged hollow conducting sphere