UP PGT Physics Mock Test - 10 - UPTET MCQ

Let φ_A, φ_B and φ_C are the electric flux linked with surface is A, B and C.
According to Gauss theorem,

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.

Where E=0 this point is called neutral point.
it is the point where electric field of both charge is same
we know tha t E=kQ/r^2
here k=1/4pi€
for 4q charge
let at ''a'' distance we get E=0 which is from q charge
so distance from 4q of 'a' point is 30-a
electric field by 4q charge on a is
E=k4q/(30-a)^2
electric field by q charge on a point
E=kq/a^2
both electric field are equal so put them equal
k4q/(30-a)^2=kq/a^2
solve this we get
4a^2=(30-a)^2
2a=30-a
3a=30
a=10
so at a distance 10cm from charge q we get E=0
distance from 4q charge 30-10=20cm.

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.

Xc ≈ 0.026 Ohms

Potential difference(V) across the terminals of a cell
i. Discharging of cell when cell is supplying current,
Therefore, V=V_P+V_Q=E-Ir, i,r., V<E
ii. charging of cell when cell is taking current,
V=VP-V_Q=E+Ir, i.e., V>E
iii. When the cell is short circuited i.e., external resistance is zero,
=> I=E/r
=>  V=V_P-V_Q=E-Ir=0 i.e., V=0

Velocity of ball at top = V1 = VT + VCOM

Velocity of ball at bottom = V₂ = | VT – VCOM |

V₁ >> V₂ than other option.

∴ More pressure difference is created because

 constant

We know that r_n​∝n²
Given: r_n+1​−r_n​=r_n−1​
∴(n+1)²−n²=(n−1)²
n=4

The unit of inductance in the SI system is the henry (H), named after American scientist Joseph Henry, which is the amount of inductance which generates a voltage of one volt when the current is changing at a rate of one ampere per second.

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

If the distance of a point charge, kept on the axis of a dipole, is sufficiently large than the separation between the charges of a dipole, then it can be shown that electric field E at a distance r from the dipole varies as E α 1/r³. Now if the distance becomes 2r, electric field intensity will decrease by a factor of 2³=8 times. Therefore the force F will now become F/8.

The current in 2W resistor will be zero because it is not a part of any closed loop.

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

When 5eV is incident the kinetic energy is 2eV it simply means the work function is W=5eV−2eV=3eV
Similarly, when 6eV is incident the kinetic energy should be   6eV−W=6eV−3eV=3eV
 it simply means to stop them we need a negative potential at anode equal to 3eV/e​=3V
So, the answer is −3V i.e. option B is correct.

Modulus of elasticity= stress/strain =(F/A)/(ΔL/L) So, for same stress Modulus of elasticity ∝( L/ΔL)and ΔL for rubber is more as compared to steel so Modulus of elasticity for rubber will be less as they are inversely proportional and also ΔL/L is less for steel

When velocity is uniform, velocity-time graph is straight line parallel to time axis. So, the slope is zero.

Electric flux density is the charge per unit area. Hence it is a function of charge and not any of the other values.

Use the vector for m of B and v in the formulae to get the instantaneous direction of force at x = a and x = 2a.

An isobaric expansion of a gas requires heat transfer to keep the pressure constant. An isochoric process is one in which the volume is held constant, meaning that the work done by the system will be zero.

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,

As the field diminishes the current is induced in the coils such that if opposes the diminishing of the field. Hence, current is induced in clockwise directing in both the loops.
And as the loops are closed no current will come out of the loops and no current at point R.
Hence option A C D is the correct option.

E.l = V   where,
E = electric field intensity = 12 N/C
V = electric potential = 6 J/C
=> distance between A and B, 
l = (6 / 12) m or (1 / 2) m = 0.5 m
 

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

x₁ + x₃ = l

Differentiating with respect to time,

  we get,  v₁ + v₃ = 0

  Again differentiating with respect to time, 

Differentiating with respect to time,  v₁ + v₂ – 2v₃ = 0  

Again differentiating with respect to time, a₁ + a₂ – 2a₃ = 0  

Here,
Aperture, a = 4 mm = 4 × 10-3 m
Wavelength, λ = 400 nm = 400 × 10-9 m = 4 × 10-7 m 

Ray optics is good approximation upto distances equal to Fresnel's distance (ZF).
Fresnel's distance is given by,

Power=IV
Where I=V_rms value of current=I_V
And V=V_rms value of voltage=E_V
Therefore, P=E_VI_V

157900  implies that the population is believed to be within the range of about 157850 to about 157950.

In other words, the population is 157900 ± 50. The “plus-or-minus 50” appended to this number means that we consider the absolute uncertainty of the population measurement to be 50 – (–50) = 100.

We can also say that the relative uncertainty is 100/157900, which we can also express as 1 part in 1579, or 1/1579 = 0.000633, or about 0.06 percent.