Bihar STET Paper 2 Physics Mock Test - 3 - Bihar PGT/TGT/PRT MCQ

According to the Principle of Superposition, if the particle of a medium is given an order (i.e. of oscillating sinusoidally) and then another order (similar or different), the particle simply adds the two orders vectorially (i.e. by vector method), and then oscillates by the amplitude of the resultant vector.
So if the particle of a medium is given two similar orders (i.e., both the sine waves having the same amplitude, say A) then the particle will oscillate with an amplitude, 2A, i.e., the amplitude will be doubled.

Let the acceleration due to gravity at that height is g′.

The acceleration due to gravity at some height (g′ ) = 1% of the acceleration due to gravity(g ) at the surface of the earth.

According to question

g′ = 1% of g

g′ = 1 / 100 × g

g′ = g / 100

The acceleration due to gravity at a height h above the surface of the earth is;

g′ = g (R / R+h)² , Where R is the radius of the earth.

Thus,

g / 100 = g(R / R+h)²

1 / 100 = (R / R+h)²

Taking square root on both sides we get,

1 / 10 = (R / R+h)

R+h = 10R

h = 9R

Explanation:The net acceleration of a particle in circular motion is along the radius of the circle towards the centre Only in case of uniform circular motion.

Significant Digits

Significant digits are the digits in a number that carry meaning contributing to its precision. They are used to indicate the reliability of a measurement.

Rules for determining significant digits:

1. Non-zero digits are always significant.
2. Zeros between non-zero digits are always significant.
3. Leading zeros (zeros to the left of the first non-zero digit) are never significant.
4. Trailing zeros in a number with a decimal point are significant.

Applying the rules to 0.000532:

• The first non-zero digit is 5.
• The digits following 5, which are 3 and 2, are non-zero and therefore significant.

So, the significant digits in 0.000532 are 5, 3, and 2.

The zeros before the 5 are leading zeros and do not contribute to the precision of the number, hence they are not significant.

Only electron microscope has resolution of 0.5-0.6 Angstrom which is less than the size of an atom.

Decrease in GPE of B₁ = Increase in Gravitational PE of B₂ + Increase in elastic PE of spring. 

Again applying law of conservation of mechanical energy at the mean position we get 

Suppose M₂ moves downwards with an acceleration a and the tension in the string is T.

KEY CONCEPT :

The restoring force in a simple harmonic motion is maximum in magnitude when the particle is instantaneously at rest because in SHM object’s tendency is to return to mean position and here particle is instantaneously at rest after that instant restoring force will be max to bring particle to mean position.

Explanation:

e = Rate of change of magnetic field x area

If a magnet is suspended over a container of liquid air, it attracts droplets to its poles. The droplets contain only liquid oxygen; even though nitrogen is the primary constituent of air, it is not attracted to the magnet. Explain what this tells you about the magnetic susceptibilities of oxygen and nitrogen, and explain why a magnet in ordinary, room-temperature air doesn’t attract molecules of oxygen gas to its poles.

Width of the magnetic field region where 'R' is its radius of curvature inside magnetic field,

Magnetic dip or inclination at a place is defined as the angle made by the Earth’s magnetic field with the horizontal in the magnetic meridian. It is denoted by δ.
Magnetic declination at a place is defined as the angle between the geographic meridian and magnetic meridian.

The frequency of radiation arising from the two close energy levels in hydrogen known as Lamb shift i.e. 1057 MHz is radio waves as it belongs to the short wavelength end of the electromagnetic spectrum.

Force due to surface tension acts all along the circumference of the circular plate. Therefore, force required to take away of plate is,
F = T x 2πr = 70 x 2 x 3.14 x 4 = 1758.4 dyne/cm
 

Applying pseudo force ma along the left direction of the block. 
The net acceleration along the incline will be a_effective​=acosθ+gsinθ
The time required will be L=0×t+½ ​a_effective​t²
 
⇒ √ 2L/​​ a_effective​
⇒√ 2L /acosθ+gsinθ​​
 

3. 1.5

Solution: Let the radius of curvature of the convex surface of the plano-convex lens be RRR. The focal length of a concave mirror is related to the radius of curvature by f=R2f = \frac{R}{2}f=2R​.

1. When the plane side is silvered, the system behaves as a concave mirror with focal length 30 cm. The effective focal length fefff_{\text{eff}}feff​ of this system can be found using the mirror formula and lens formula combined, but given the scenario, we focus on this system.

2. When the convex side is silvered, the system behaves like a concave mirror with focal length 10 cm.

By using the relations for combined focal length and refractive index of the plano-convex lens, and applying these boundary conditions, the refractive index nnn of the material of the lens is determined to be 1.5.

Explanation:Avogadro's law states that, "equal volumes of all gases, at the same temperature and pressure, have the same number of molecules".

• The horsepower (hp) is a unit in the foot-pound-second ( fps ) or English system, sometimes used to express the rate at which mechanical energy is expended.
• It was originally defined as 550 foot-pounds per second (ft-lb/s).
• A power level of 1 hp is approximately equivalent to 746 watt.

 So the range is 88 - 198 pF

Let, the length of wire = l unit

Fraction required =a

Then, the lenght of wire which is stretched =al

NEP 2020 aims to achieve a Gross Enrollment Ratio (GER) of 50% in higher education by 2035.

The greatest cause of failure of a new teacher is in the area of interpersonal relations. If the teacher is not able to develop a bond or relationship with the students, she will be rejected by the students and will face a lot of hardships.

In psychology, individual differences refer to the extent and kind of variations or similarities among people on some of the important psychological aspects such as intelligence, personality, interest, and aptitude.

National Education Policy 2020 is India’s First 21st Century Education Policy. Which makes many relevant changes in the education system from elementary education to Higher education.

Key PointsAccording to NEP 2020:

• ​A "5+3+3+4" curriculum framework is planned as part of the 2020 education reform.
• Based on age divisions, NEP 2020 has divided schooling into several phases.
• The policy prioritizes three years of preschool and twelve years of formal education.

Thus, classes 3rd to 5th are​ included in the preparatory stage as per the new education policy 2020

The term used interchangeably with 'Motivation' is 'Need'. 
Motivation is a term that means the motive behind something. It means a person wants something, has a desire for something, wants to avoid something, and wants to escape from something. Having a desire for something is related to need. When we need something, then only a desire creates to have that thing.
Thus, this is the correct answer.

Manganese is one of the important raw materials used for smelting iron ore.

Important Points

• Manganese is used for making alloys.
• It is used in manufacturing of enamel, dry cell batteries, plastics, chemicals and glasses.
• It requires almost 10 kg of manganese to manufacture one tonne of steel.
• Odisha is the largest producer of manganese in India with multiple mines located over the iron ore belt of India.
• Some of the major mines are Bonai, Kendujhar, Sundergarh, Gangpur, Koraput, Kalahandi, and Bolanger.
• After Odisha, Karnataka, Maharashtra, Telangana, Goa, and Jharkhand lies in the list of manganese producer in India.
• In 2000-2001, Odisha produced one-third of the country's total production.

Thus, we can conclude that Odisha is the largest producer of manganese.

Initial number of balls = 90 + 110 + 150 + 50 = 400
Balls removed = 50% of 90 + 70% of 110 = 122
Remaining balls = 278

Hence, Option D is correct.

From the diagram given below:

The shaded part represents the persons who speak only two languages.

26 + 51 + 17

= 94 

Hence, the correct answer is "94".