UP PGT Physics Mock Test - 10 - UPTET MCQ

The magnetic susceptibility of diamagnetic materials doesn’t depend upon temperature. This is often because there’s an outsized barrier between the bottom state and therefore the excited states of diamagnetic substances. Hence, it remains constant during the change of temperature. All the other statements are false.

A particle representing a quantum of light or other electromagnetic radiation. A photon carries energy proportional to the radiation frequency but has zero rest mass.

When a tangent is drawn at any point on field line then that tangent gives the direction of electric field at that point

Rate of change of area with remain same even if wire is replaced by semi-circular wire, 
∴ induced current will be same as earlier one as I = (e/R) & e i.e. induced emf is function of area because
e = – N (dɸ/dt) = – N (d/dt) (ABcoswt).
 

Mathematical constants don't have any dimensions hence, it is dimensionless and phase constant is in angle therefore, the unit is radian.

Water is used as a coolant in automobiles radiators because it has high specific heat capacity. So, it absorbs a large amount of heat for a degree rise in temperature.

Given, u=−20cm
m=−3⇒−v/u ​=−3
v=−60cm
1/f=(1/v​)+(1/u)​=(-1/60)​−(1/20)​=−1−3/60​
f=−60/4​=−15cm
 

We know that,       g = G. m₁ m₂ / r₂
Where we know g has dimensions of acceleration
Thus [G] = [ g.r² /m₁ m₂]
= N m²kg^-2

Force on particle=F=qE
Hence, acceleration of particle=a=F/m​=qE/m​
Initial speed=u=0
Hence, final velocity=v=u+at=qEt/m​
Kinetic energy=K=(1/²)​mv2=(1/2)​m(qEt/m​)2
⟹K=E²q²t²​/2m

Unit of resistance should be 20ohm

Solution :- Resistance, R= ρl/A

When length l increases three times, the cross section A will decease three times of previous. So length becomes 3l and cross section becomes A/3.

Now resistance becomes ,R  = ρ3l / πA/3

​ =9R=9×20=180Ω

Correct Answer :- d

Explanation : a) A topological sort of a directed acyclic graph (DAG) is any ordering m1, m2, …, mn of the nodes

of the graph, such that if mimj is an edge then mi appears before mj . Any topological sort of a

the dependency graph gives a valid evaluation order for the semantic rules. 

b) The parse tree can be annotated with synthesized or inherited attributes. The parse tree can also be indicated with an arrow mark to indicate the manner in which the value gets propagated between the nodes of the parse tree. This graph is called as dependency graph as it indicates the dependency between nodes for deriving the values. This graph is an acyclic graph which doesn’t have a cycle. The presence of a cycle indicates that the graph is incorrect as the dependence of nodes for deriving values cannot be predicted. Edges in the dependence graph show the evaluation order for attribute values and thus the graph is a directed one.

At null point (and along the axis), earth's magnetic field and bar's magnetic field are opposite in direction.
On the equatorial line, the bar's magnetic field is opposite in direction to its field on the axis. Hence, on the equatorial line, the two fields add up.
As the null points are on the axis of the bar magnet, therefore,
B1= (μ0/4π)(2M/d3)=H
On the equatorial line of magnet at same distance(d), field due to the magnet is 
B2= (μ0/4π)(M/d3)=B1/2=H/2
Therefore, total magnetic field at this point on equatorial line is 
B=B2+H=3H/2=3×0.36G/2=0.54G
 

The magnetic field at O due to current in DA is

 (directed vertically upwards)

The magnetic field at O due to current in BC is

(directed vertically downwards)

The magnetic field due to current AB and CD at O is zero.
Therefore the net magnetic field is B = B₁-B₂ (directed vertically upwards)

If a magnet is freely suspended or inclined or dipped, the angle between the horizontal and the angle of inclination of the magnet that is inclined only by the earth’s magnetic field will indicate the magnetic latitude. The relation is as follows:
tanδ=2tanλ

Explanation:Vector addition is the operation of adding two or more vectors together into a vector sum. The so-called parallelogram law gives the rule for vector addition of two or more vectors. For two vectors, the vector sum is obtained by placing them head to tail and drawing the vector from the free tail to the free head.

• When an object is moving along a straight path, the magnitude of average velocity is equal to the average speed.
• Therefore, the numerical ratio of average velocity to average speed is one in a straight line motion.
• But, during curved motion, the displacement < distance covered, so the velocity < speed.

​Therefore, the numerical ratio of average velocity to average speed is equal to or less than one but can never be more than one. 

By dimensional analysis

but by superposition

Because of the centre of the larger cube lies at a corner of the eight smaller cubes of which it is made
therefore,

The Davisson-Germer experiment demonstrated the wave nature of the electron, confirming the earlier hypothesis of deBroglie. Putting wave-particle duality on a firm experimental footing, it represented a major step forward in the development of quantum mechanics. The Bragg law for diffraction had been applied to x-ray diffraction, but this was the first application to particle waves.

Given:
Frequency of radio signal n=9×10 ⁹Hz
 Frequency shift n0=3×10³Hz
 Velocity of radio signal v=3×10⁸m/s
 Frequency shift shown by reflected wave is Shift =n−n
=>n−n=(v+u/v−u)n−n
 
Shift=(2u/v−u)ⁿ
Now, putting the given values in Eq. (i), we get,
3×10³=(2u/3×10^-8−u)9×10⁹
                    
⇒3×10⁸−u=2u×9×10⁹/3×10³
=6u×10⁶
⇒6×10⁶u+u=3×10⁸
 
u(6×106+1)=3×10⁸
 
u(6000001)=3×10⁸
 
u=3×10⁸/6000001=49.999≈50m/s

We know that the horizontal range for any projectile motion let say R = 2u².sin 2a /g
Where u is initial speed, and a is the angle at which the particle is thrown, which is responsible for direction. So in between the possible range of a that is 0 - 90, there are maximum two equal values of sin 2a, thus the maximum number of directions for the same or equal range are 2.

At the highest point, its vertical velocity will become zero. Hence the only left velocity is horizontal which remains unchanged and is equal to 10 cos 60 = 5m/s

Electromagnetic waves vary in wavelength and frequency. Longer wavelength electromagnetic waves have lower frequencies, and shorter wavelength waves have higher frequencies. Higher frequency waves have more energy.

We know that E = hv , where E is energy and v is frequency.
Thus we get h = E/v
And [h] = [E/v] = ML²T^-2 / T^-1
= ML²T^-1
[P] = MLT^-1
[F] = MLT^-2
[Angular momentum] = [P x r] = ML²T^-1

Coefficient of performance(cop) of a refrigerator,
β= Q₂/Q₁-Q₂=T₂/T₁-T₂=277/300-277=277/23≈12
OR, Q₂/W=12. Therefore, W=1J.Q₂=12J
Also, Q1=Q2+W
=(12+1) J
=13J

In the Geiger-Marsden experiment very small deflection of the beam was expected because positive charge and the negative electrons are distributed through the whole atom reducing electric field inside the atom.

UVA radiation is what makes people tan. UVA rays penetrate to the lower layers of the epidermis, where they trigger cells called melanocytes (pronounced: mel-an-oh-sites) to produce melanin. Melanin is the brown pigment that causes tanning. Melanin is the body's way of protecting skin from burning.

Application of Bernoulli’s theorem larger area of cross section implies less velocity which in turn implies higher pressure.