UP PGT Physics Mock Test - 1 - UPTET MCQ

Explanation:explanation none

In a series RLC circuit there becomes a frequency point were the inductive reactance of the inductor becomes equal in value to the capacitive reactance of the capacitor. In other words, XL = XC.
Series Resonance circuits are one of the most important circuits used electrical and electronic circuits.
 

Explanation:for electromagnetic induction magnet and coil both may move but relative motion between must be present

Electric force on a charge q placed in a region o electric field intensity is E and it is given by F = qE.
In this case, F = 100 N and q = 2 C.
So, E=F/q​=100N/2C​=50 N/C.
Hence, the value of field intensity will be 50 N/C.

Scalar quantity gives you an idea about how much of an object there is, but vector quantity gives you an indication of how much of an object there is and that also in which direction. So, the main difference between these two quantities is associated with the direction, i.e. scalars do not have direction but vectors do. 

Changes(if required): The answer provided in the forum is wrong, The correct answer would be option B.
Solution:
Given,
V_R-rms =30.0V
V_C-rms=90.0V
V_L-rms=50.0V
To find the root mean square voltage across the source, we will use the formula,
V_rms=√[V_r²+(V_L-V_C)²]
=√[(30.0V)² +(50.0V-90.0V)²]
=50.0 V

The parsec (symbol: pc) is a unit of length used to measure large distances to astronomical objects outside the Solar System. A parsec is defined as the distance at which one astronomical unit subtends an angle of one arcsecond, which corresponds to 648000π astronomical units.

The sole reason is 'refraction' in a single word. Refraction of waves involves a change in the direction of waves as they pass from one medium to another. Refraction, or the bending of the path of the waves, is accompanied by a change in speed and wavelength of the waves. Water waves travel fastest when the medium is the deepest. Thus, if water waves are passing from deep water into shallow water, they will slow down. But here it is traveling from shallow water to deep water, then the waves bend in the opposite direction.

Weight is a force caused by gravity. The weight of an object is the gravitational force between the object and the Earth. The more mass the object has the greater its weight will be. Weight is a force, so it's measured in newtons.

Assume the mirror is at the origin and it is moving about the origin along x direction between x = -2 and x = +2 as its extreme positions.
Assume that the object is placed at co=ordinate of x = - (2+x)
So, when mirror is at position x = -2, the object's image will be formed at x coordinate X = - 2+x 
And when the mirror is at position x = +2, the image is formed at X = 6+x 
So, the net difference in the position of image between these 2 co-ordinates is ( 6 + x  ) - ( -2 + x ) = 8
So, the amplitude will be half of this distance. So the answer is 8/2 = 4 cm. 
Option C is correct.
 

• Yes, sound waves are longitudinal, meaning that they oscillate parallel to the direction of their motion. So diffraction takes place in the sound waves.
• Since there is no component of a sound wave's oscillation that is perpendicular to its motion, sound waves cannot be polarized.

The forces acting on the body are the force of gravity and the air friction. By work energy theorem, the total work done on the body is
W=1/2m(1.2√gH)2−0=0.72mgH
The work done by the force of gravity is mgH.
. Hence, the work done by the air friction is,
=0.72mgH-mgH
=00.28mgH.
 

The charged particle will move along the lines of electric field (and magnetic field). Magnetic field will exert no force. The force by electric field will be along the lines of uniform electric field. Hence the particle will move in a straight line.

Given that λ = 200nm, d=700nm
θ = λ/d
We know that maximum angle can be 90⁰
No of rings that can be obtained say n,

If θ is so small then −

Division of wave front where wave front is divided into two or more parts with the help of mirrors, lenses and prisms. The common methods are : Young's double slit arrangement, Fresnel's biprism method, Lloyd’s mirror method etc.
 
Division of amplitude where amplitude of the incoming beam is divided into two or more parts by partial reflection or refraction. These divided parts travel different paths and reunited later to produce interference. E.g. Newton's rings, Michelson’s interferometer etc.
 

The unit for electromotive force is Volt.
EMF is numerically expressed as the number of Joules of energy given by the source divided by each Coulomb to enable a unit electric charge to move across the circuit.
Volts=Joules/Coulombs

KEY CONCEPT : Magentic field at the centre of a circular coil of radius R carrying current i is 

Given : n ´ (2pr ') =2pR

⇒ nr '=R ...(1)

from (1) and (2), 

Electric flux = electric field intensity x area. The dimension of field intensity is [M L T^-3 I^-1] and the dimension of the area is [L²]. Therefore, the dimension of flux = [M L³ T^-3 I^-1]. This can also be justified as flux=potential x length. By putting the dimensions of potential and length, we can get the same result.

Given,

m= 0.3 kg, x = 20cm and k = 15N/m

F= -kx    ..(i)
and F = ma    ..(ii)
∴   ma = -kx

The light-year is a unit of length used to express astronomical distances and measures about 9.46 trillion kilometres or 5.88 trillion miles. As defined by the International Astronomical Union, a light-year is the distance that light travels in vacuum in one Julian year. 

Gamma rays are electromagnetic radiation (high-energy photons) with an extreme frequency and a high energy. They are created by the decay of nuclei as they travel from a high-energy state to a lower state; this process is called “gamma decay.” Most atomic responses are accompanied by gamma emission.

The magnetic field is perpendicular to the plane of the paper. Let us consider two diametrically opposite elements. By Fleming's left hand rule, on element AB the direction of force will be leftwards and the magnitude will be 

dF = I ( d l)Bsin 90°= I ( dl)B

On element CD, the direction of force will be towards right on the plane of the paper and the magnitude will be

dF = I ( d l)B.
These two forces will cancel out.
NOTE : Similarly, all forces acting on the diametrically opposite elements will cancel out in pair. The net force acting on the loop will be zero.

Until and unless the velocity of any object comes to zero, any peek in its displacement-time graph can’t be achieved. Which means for the height to be maximised the velocity must become zero. And any time of this motion the acceleration is always a constant downward due to gravity.

In SI units, permeability is measured in Henries per meter H/m or Hm−1.
Henry has the dimensions of [ML²T⁻²A⁻²].
Dimensions for magnetic permeability will be [ML²T⁻²A⁻²]/[L]=[MLT⁻²A⁻²]

Dimension of N = [L - 3]

The final velocities in case of one dimensional semi elastic collision are
V1 = {(m1 - em2)/(m1 + m2)}u1 + {(1 + e)/(m1 + m2)}m2u2
V2 = {(m2 - em1)/(m1 + m2)}u2 + {(1 + e)/(m1 + m2)}m1u1
Here, u1 = u and u2 = 0; e = (2/3) and m1 = m2 = m
By substituting these values we get V2: V1 = 5 : 1

Correct option is B.

KEY CONCEPT : When a charged particle is moving at right angles to the magnetic field then a force acts on it which behaves as a centripetal force and moves the particle in circular motion.