UP PGT Physics Mock Test - 6 - UPTET MCQ

We have  1 unit = x meters
So  1 unit² = x² meter²
Hence, we get  1 meter² = 1/x² unit²

as the maximum current that can be drawn from a cell is for R =0 therefore, it is I = E/r.

The magnetic field near the conducting rod due to long current carrying wire is 
B= μ₀​I/2πr ​ (using Ampere's law, ∫B.dl=μ_0​I)
Now, induced emf due to moving rod is e=Blv= (μ₀​I/2πr) ​×lv= μ₀​vIl/2πr

Unit of resistance should be 5ohm.

Resistance of a wire is given by the formula 




 

On releasing, the motion of the system will be according to figure.

m₁g - T = m₁a    ...(i)

and T-m₂g = m₂a   ...(ii)

on solving

Here

m₁ = 5 kg , m₂ = 4.8 kg

g=9.8 ms^-2

Correct Answer : C

Explanation : The adiabatic condition is given by the relation between pressure volume and temperature volume as:

(PV)γ = constant 

where, γ = Cp/Cv is ratio of the specific heats

These relations suggest that an decrease in volume is associated with increase in temperature

ATQ 

P₁(V₁)γ = (P₂V₂)γ

=> P₁(1)² = P₂(4)²

P₁/P₂ = 16

The angular momentum L of the particle is given by

= 4t-3
At t = 0.25s
e= 2V

The total charge enclosed in the dotted portion when the switch S is open is zero. When the switch is closed and steady state is reached, the current I coming from the battery is 9 = I (3 + 6) ⇒ I = 1A

∴ Potential difference across 3Ω resistance = 3V and potential difference across 6Ω resistance = 6V

∴ p.d. across 3 µF capacitor = 3V an d p.d. across 6 µF capacitor = 6V

∴ Charge on 3 µF capacitor Q1 = 3 × 3 = 9 µC Charge on 6 µF capacitor Q2 = 6 × 6 = 36 µC The total charge enclosed in the dotted portion =

∴ Charge passing the switch = 36 – 9 = 27 µC

If light from a continuous spectrum passes through a cool, transparent gas we observe dark lines appear in the spectrum. The lines occur where atoms of the gas have absorbed specific wavelengths of light. Hence we call this type of spectrum an absorption spectrum.
 

The phenomenon of interference is based on the principle of superposition.

Given,
P_avg=1200W
V_rms=120 Volts
A,
The resistance is,
R=V_rms²/P_avg
So,R=120²/1500=9.6ohm
B,
The rms current is,
I_rms=V_rms/R
So, I_rms=120/9.6
=>I_rms=12.5A
C,
The maximum instantaneous power is,
P_m=2P_avg
So,P_m=2(1500)
=>P_m=3000W.
Hence option D is the correct answer.
 

The rate is given as dQ/dt = KAdT/dx

According to Fleming’s right-hand rule induced current flows from Q to P.
Hence P is at higher potential and Q is at lower potential. 
Therefore, A is positively charged and B is negatively charged.
Hence:
q_A​=+800μC and q_b​=−800μC

Electric potential is a pure Scalar quantity, The reason is as follows.
The Electric Potential is defined as the amount of work-done per unit positive charge to bring from infinity to that point under the influence of the primary charge only.
U=W/q
And work done is defined as the dot product of force and displacement which is a scalar quantity.
W=F.S
Thus Electric potential is a scalar quantity.

Natural frequency is the frequency at which a body tends to oscillate in the absence of any driving or damping force.
Free vibrations of any elastic body are called natural vibration and happen at a frequency called natural frequency. Natural vibrations are different from forced vibration which happen at frequency of applied force .

If the intensity of central maxima is I, then intensity due to individual source must be I/4. So, if one of the slit is closed then due to remaining slit, intensity will be I/4.

G = 6.67 x 10-11 Nm2/kg2

so, when expressed in VGS units we shall convert N to dynes, m to cm and kg to g, thus

G = 6.67 x 10-11 x [(105dynes x (102)2cm2 ) / (103)2 g2]

=  6.67 x 10-11 x [ (105 x 104 ) / 106 ] 

Thus,

in CGS system

G = 6.67 x 10-8 dyne.cm2/g2

In a.c. circuits, a choke coil is used to control the current in place of a resistance. If a resistance is used to control the current, the electrical energy will be wasted in the form of heat. Due to its inductive reactance, a choke coil decreases the current without wasting electrical energy in the form of heat.

Light as a wave: Light can be described (modeled) as an electromagnetic wave. In this model, a changing electric field creates a changing magnetic field. This changing magnetic field then creates a changing electric field and BOOM - you have light. Unlike many other waves (sound, water waves, waves in a football stadium), light does not need a medium to “wave” in.

From conservation of angular momentum, 
mr₀ = r/2 = mvr
⇒ v = v₀/2
From conservation of energy,

Explanation:kinetic energy is transferred to other forms of energy—such as thermal energy, potential energy, and sound—during the collision process. After collision if recovery of kinetic energy is less than % then it is called inelastic collision i.e.. some part of kinetic energy is not recover. So that in an inelastic collision the total kinetic energy after the collision is less than before the collision

In Thomson's model, the atom is composed of electrons surrounded by a soup of positive charge to balance the electrons' negative charges, like negatively charged “plums” surrounded by positively charged “pudding”. The 1904 Thomson model was disproved by Hans Geiger and Ernest Marsden's 1909 gold foil experiment.

Copper is a metal whereas Germanium is Semi-conductor.
NOTE : Resistance of metal decreases and semiconductor increases with decrease in temperature.

In a p-type semiconductor, the holes are the majority carriers, while the electrons are the minority carriers. A p-type semiconductor is obtained when trivalent atoms, such as aluminium, are doped in silicon atoms.

Because velocity is the slope of the x-t graph.(dx/dt=V) and by looking at the graph it can be seen that upto time T₀ slope is constant so velocity will be constant and after time T0 slope is zero ( line is parallel to X axis) so the velocity will be zero.

This consists of two dipoles, –q and +q with dipole moment along with the +y-direction and –q and +q along the x-direction.


Along the direction 45° that is along OP, where P is (+a, +a, 0).