Category: NEET Physics Objective Questions

NEET  Physics is the very imporatant paper in the Medical Entrance EXAM. So these NEET Physics MCQs with Answers for all Concepts as per the new syllabus. Practice daily with these NEET Physics objective questions on air pollution knowledge & problem-solving skills along with time management. NEET Physics Valve Electronics (Diode and Triode) Multiple Choice Questions make you feel confident in answering the question in the

MCQs on Valve Electronics (Diode and Triode) :

1. Number of secondary electrons emitted per number of primary electrons depends on
(A) Material of target
(B) Frequency of primary electrons
(C) Intensity
(D) None of the above

Answer

Answer: (C) Intensity

2. In a diode, when there is saturation current, the plate resistance is
(A) Zero
(B) Infinite
(C) Some finite quantity
(D) Data is insufficient

Answer

Answer: (B) Infinite

3. The grid voltage of any triode valve is changed from 1 volt to 3 volt and the mutual conductance is 3 x 10^-4 mho. The change in plate circuit current will be
(A) 0.8 mA
(B) 0.6 mA
(C) 0.4 mA
(D) 1 mA

Answer

Answer: (B) 0.6 mA

4. For a given plate voltage the plate current in a triode is maximum when the potential of
(A) The grid is positive and the plate is negative
(B) The grid is positive and the plate is positive
(C) The grid is zero and the plate is positive
(D) The grid is negative and the plate is positive

Answer

Answer: (B) The grid is positive and the plate is positive

5. The amplification factor of a triode is 20. If the grid potential is reduced by 0.2 volt then to keep the plate current constant its plate voltage is to be increased by
(A) 10 volt
(B) 4 volt
(C) 40 volt
(D) 100 volt

Answer

Answer: (B) 4 volt

6. The amplification produced by a triode is due to the action of
(A) Filament
(B) Cathode
(C) Grid
(D) plate

Answer

Answer: (C) Grid

7. In a triode amplifier, the value of maximum gain is equal to
(A) Half the amplification factor
(B) Amplification factor
(C) Twice the amplification factor
(D) Infinity

Answer

Answer: (B) Amplification factor

8. The voltage gain by the triode depends on
(A) Filament voltage
(B) Plate voltage
(C) Plate resistance
(D) Plate current

Answer

Answer: (C) Plate resistance

9. In a triode valve
(A) If the grid voltage is zero then plate current will be zero
(B) If the temperature of the filament is doubled, then the thermionic current will also be doubled.
(C) If the temperature of the filament is doubled, then the thermionic current will nearly be four times
(D) At a definite grid voltage, the plate current varies with plate voltage according to Ohm’s law

Answer

Answer: (C) If the temperature of the filament is doubled, then the thermionic current will nearly be four times

10. In the circuit of a triode valve, there is no change in the plate current, when the plate potential is increased from 200 volt to 220 volt and the grid potential is decreased from 0.5 volt to 1.3 volt. The amplification factor of the valve is
(A) 15
(B) 20
(C) 25
(D) 35

Answer

Answer: (C) 25

NEET  Physics is the very imporatant paper in the Medical Entrance EXAM. So these NEET Physics MCQs with Answers for all Concepts as per the new syllabus. Practice daily with these NEET Physics objective questions on air pollution . NEET Physics Non-uniform Circular Motion Multiple Choice Questions

MCQs on Non-uniform Circular Motion :

1. A bottle of soap water is grasped by the neck and swings briskly in a vertical circle. Near which portion of the bottle do the bubbles collect
(A) Near the bottom
(B) In the middle of the bottle
(C) Near the neck
(D) Uniformly distributed in the bottle

Answer

Answer: (C) Near the neck

2. A bucket tied at the end of a 1.6 m long spring is whirled in a vertical circle with constant speed. What should be the minimum speed so that the water from the bucket does not spill when the bucket is at the highest position?
(A) 4 m/sec
(B) 6.25 m/sec
(C) 16 m/sec
(D) None of the above

Answer

Answer: (A) 4 m/sec

3. A1 Kg stone at the end of 1 m long string is whirled in a vertical circle at a constant speed of 4 m/sec. The tension in the string is 6 N, when the stone is at
(A) Top of the circle
(B) Bottom of the circle
(C) Halfway down
(D) None of the above

Answer

Answer: (A) Top of the circle

4. A cane filled with water is revolved in a vertical circle of radius 4 metres and the water just does not fall down. The time period of revolution will be
(A) 1 sec
(B) 10 sec
(C) 8 sec
(D) 4 sec

Answer

Answer: (D) 4 sec

5. A 2 Kg stone at the end of a string 1 m long is whirled in a vertical circle at a constant speed. The speed of the stone is 4 m/sec. The tension in the string will be 52N, when the stone is
(A) At the top of the circle
(B) At the bottom of the circle
(C) Halfway down
(D) None of these

Answer

Answer: (B)At the bottom of the circle

6. The string of pendulum of length l is displaced through 90⁰ from the vertical and released. Then the minimum strength of the string in order to withstand the tension, as the pendulum passes through the mean position is
(A) mg
(B) 3 mg
(C) 5 mg
(D) 6 mg

Answer

Answer: (B) 3 mg

7. In a vertical circle of radius r, at what point in its path does a particle have tension equal to zero, if it is just able to complete the vertical circle
(A) Highest point
(B) Lowest point
(C) Any point
(D) At a point horizontally from the centre of the circle of radius r

Answer

Answer: (A) Highest point

8. A hollow sphere has a radius of 6.4 m. Minimum velocity required by a motorcyclist at the bottom to complete the circle will be
(A) 17.7 m/s
(B) 10.2 m/s
(C) 12.4 m/s
(D) 16.0 m/s

Answer

Answer: (A) 17.7 m/s

9. A fan is making 600 revolutions per minute. If after some time it makes 1200 revolutions per minute, then increase in its angular velocity
(A) 10 π rad /sec
(B) 20 π rad /sec
(C) 40 π rad /sec
(D) 60 π rad /sec

Answer

Answer: (B) 20 π rad /sec

10. A stone tied with a string, is rotated in a vertical circle. The minimum speed with which the string has to be rotated
(A) Is independent of the mass of the stone
(B) Is independent of the length of the stone
(C) Decreases with increasing mass of the stone
(D) Decreases with increasing length of the stone

Answer

Answer: (A) Is independent of the mass of the stone

NEET  Physics is the very imporatant paper in the Medical Entrance EXAM. So these NEET Physics MCQs with Answers for all Concepts as per the new syllabus. Practice daily with these NEET Physics objective questions on air pollution . NEET Physics Electric flux Multiple Choice Questions

MCQs on Electric flux :

1. What is the value of total flux through the faces of the cube with the sides of length a if a charge Q is placed at corner A of the cube is

(A) q/ε₀
(B) q/2ε₀
(C) q/4ε₀
(D) q/8ε₀

Answer

Answer: (D) q/8ε₀

2. If a unit positive charge is kept in the air. Then the total flux coming out of unit charge is
(A) 4πε₀^-1
(B) 4πε₀
(C) ε₀^-1
(D) ε₀

Answer

Answer: (C)ε₀^-1

3. What is the value of electric flux (Φ) on a plane of area 1m² on which an electric field of 2 V/m crosses with an angle of 30⁰.
(A) 1 Vm
(B) 2 Vm
(C) 3 Vm
(D) 4 Vm

Answer

Answer: (A) 1 Vm

4. Determine the electric flux of a flat square having an area of 10m² is a uniform electric field of 8000 N/C passing perpendicular to it
(A) 8 x 10⁵ Nm^2/C
(B) 8 x 10⁴ Nm²/C
(C) 16 x 10⁵ Nm²/C
(D) 4 x 10⁴ Nm²/C

Answer

Answer: (A) 8 x 10⁵ Nm^2/C

5. A plane surface is rotated in a uniform electric field. When is the flux of the electric field through the surface maximum?
(A) When the surface is perpendicular to the field
(B) When the surface is parallel to the field
(C) When the surface is at an angle of 30⁰ with the field
(D) When the surface is at an angle of 45⁰ with the field

Answer

Answer: (A) When the surface is perpendicular to the field

6. When is the flux through a surface taken as positive
(A) When the flux lines are directed inwards
(B) When the flux lines are directed outwards
(C) No flux lines through the surface
(D) Flux lines are parallel to each other

Answer

Answer: (B) When the flux lines are directed outwards

7. The net charge through a closed surface in a given medium depends on
(A) Size of the surface
(B) Charge of the surface
(C) The shape of the surface
(D) Area of the surface

Answer

Answer: (B) Charge of the surface

8. The dimension of electric flux is
(A) [M²L²T³A¹]
(B) [MLT^-3A^-1]
(C) [M³L³T^-3A^-1]
(D) [ML³T ^-3A^-1]

Answer

Answer: (D) [ML³T ^-3A^-1]

9. The electric flux through a cubical Gaussian surface enclosing net charge q is q/ε_0. While the electric flux through one face of a cube is
(A) q/ε₀
(B) q/6ε₀
(C) q/4πε₀
(D) q/4ε₀

Answer

Answer: (B) q/6ε₀

10. A point charge q is placed at a distance a/2 directly above the centre of the square of side a. The electric flux through the square is
(A) q/ε₀
(B) q/6ε₀
(C) q/4πε₀
(D) q/4ε₀

Answer

Answer: (B) q/6ε₀
Explanation : Imagine a cube with charge q at the centre and the given square is one of its faces. So electric flux through the given square( one face) q/6ε₀

NEET  Physics is the very imporatant paper in the Medical Entrance EXAM. So these NEET Physics MCQs with Answers for all Concepts as per the new syllabus. Practice daily with these NEET Physics objective questions on air pollution knowledge & problem-solving skills along with time management. NEET Physics Dual Nature of Matter and Radiation Multiple Choice Questions exam & increases your scores to high.

MCQs on Dual Nature of Matter and Radiation :

1. Light of frequency 1.9 times the threshold frequency is incident on a photosensitive material. If the frequency is halved and intensity is doubled, the photocurrent becomes
(A) doubled
(B) quadrupled
(C) halved
(D) zero

Answer

Answer: (D) zero

2. For a metal having a work function W_0, the threshold wavelength is λ. What is the threshold wavelength for the metal having work function 2W0?
(A) λ/4
(B) λ/2
(C) 2λ
(D) 4λ

Answer

Answer: (B) λ/2

3. Radiation of frequency ν is incident on a photosensitive metal. When the frequency of the incident radiation is doubled, what is the maximum kinetic energy of the photoelectrons?
(A) 4E
(B) 2E
(C) E + hν
(D) E – hν

Answer

Answer: (C) E + hν

4. How does the maximum kinetic energy of a photoelectron vary with the frequency (v) of the incident radiation?

Answer

Answer: (B)

5. The stopping potential V₀ for photoelectric emission from a metal surface is plotted along with the y-axis and frequency v of incident light along the x-axis. A straight line is obtained as shown. Planck’s constant is given by

(A) product of the slope of the line and charge on the electron
(B) intercept along y-axis divided by the charge on the electron
(C) product of the intercept along x-axis and mass of the electron
(D) the slope of the line

Answer

Answer: (A) product of the slope of the line and charge on the electron

6. Calculate the de Broglie wavelength associated with the electron which has a kinetic energy of 5 eV.
(A) 5.47 Å
(B) 2.7 Å
(C) 5.9 Å
(D) None of the above

Answer

Answer: (A) 5.47 Å

7. What is the ratio of the de Broglie wavelengths proton and an α particle if they are accelerated by the same potential difference?
(A) 2√2: 1
(B) 3:2
(C) 3√2: 1
(D) 2: 1

Answer

Answer: (A) 2√2: 1

8. Which of the following graphs represent the variation of particle momentum associated with de Broglie wavelength?

Answer

Answer:  (C)

9. By what factor will the de Broglie wavelength change if the K.E if the free electron is doubled?
(A) ½
(B) (frac { 1 }{ sqrt { 2 } } )
(C) 2
(D) √2

Answer

Answer: (B) (frac { 1 }{ sqrt { 2 } } )

10. In photoelectric effect what determines the maximum velocity of the electron reacting with the collector?
(A) Frequency of incident radiation alone
(B) The potential difference between the emitter and the collector
(C) The work function of metal
(D) All of these

Answer

Answer: (D) All of these

11. Who among the following established that electric charge is quantised?
(A) R.A. Millikan
(B) Wilhelm Rontgen
(C) William Crookes
(D) J.J. Thomson

Answer

Answer: (A) R.A. Millikan

12. By which of the following physical processes can minimum energy required for the electron emission from the metal surface be supplied to the free electrons?
(A) Field emission
(B) Thermionic emission
(C) Photoelectric emission
(D) All of these

Answer

Answer: (D) All of these

13. Which of the following statements is true regarding the photoelectric experiment?
(A) The stopping potential increases with the increase in the intensity of incident light.
(B) The photocurrent increases with the intensity of light.
(C) The photocurrent increases with the increase in frequency
(D) All of the above

Answer

Answer: (B) The photocurrent increases with the intensity of light.

NEET  Physics is the very imporatant paper in the Medical Entrance EXAM. Here, you will discover the NEET Physics MCQs with Answers for all Concepts as per the new syllabus. Practice more on a regular basis with these NEET Physics objective questions on air pollution . NEET Physics Oscillations and Waves Multiple Choice Questions

MCQs on Oscillations and Waves :

1. On which of the following does the energy of a simple harmonic motion depend
(A) ⍵
(B) (frac{1}{omega^{2}})
(C) (frac{1}{a^{2}})
(D) a²

Answer

Answer: (D) a²

2. Calculate the amplitude for a SHM using the equation x = 3sin2pt + 4cos3pt
(A) 3
(B) 5
(C) 4
(D) 7

Answer

Answer: (B) 5

3. What is the constant of propotionality of an oscillator if the damping force is directly propotional to the velocity
(A) kg.s^-1
(B) kg.m.s^-1
(C) kg.s
(D) kg.m.s^-2

Answer

Answer: (A) kg.s^-1

4. What is the phase difference between the prongs of the tuning fork
(A) 5π
(B) π
(C) 2π
(D) 3π

Answer

Answer: (B) π

5. What is the change in the phase if a wave is reflected from a denser medium
(A) 3π
(B) 0
(C) π
(D) 2π

Answer

Answer: (C) π

6. The observer hears a sound from the source which is moving away from the observer who is stationary. Determine the frequency of the sound
(A) It is halved
(B) It remains the same
(C) It reaches infinity
(D) It gets doubled

Answer

Answer: (A) It is halved

7. The length of the pendulum which is displaying SHM is increased by 21%. Calculate the percentage increase in the periodic time of the pendulum.
(A) 21%
(B) 10%
(C) 11%
(D) 42%

Answer

Answer: (B) 10%

8. Which of the following does not exhibit polarization
(A) Longitudinal wave in a gas
(B) Transverse wave in a gas
(C) Neither (A) nor (B)
(D) Both (A) and (B)

Answer

Answer: (A) Longitudinal wave in a gas

NEET  Physics is the very imporatant paper in the Medical Entrance EXAM. So these NEET Physics MCQs with Answers for all Concepts as per the new syllabus. Practice more on a regular basis with these NEET Physics objective questions on air pollution . NEET Physics Series and Parallel Circuits Multiple Choice Questions

MCQs on Series and Parallel Circuits :

1. A certain circuit is composed of two parallel resistors. The total resistance is 1,403 Ω. One of the resistors is 2 Ω. The other resistor value is
(A) 1,403 Ω
(B) 4.7 kΩ
(C) 2 kΩ
(D) 3,403 Ω

Answer

Answer: (B) 4.7 kΩ

2. A voltage divider consists of ot two 100 kΩ resistors and a 12 V source. What will the voltage be if a load resistor of 1 MΩ is connected to the output?
(A) 0.57 V
(B) 6 V
(C) 12 V
(D) 5.7 V

Answer

Answer: (D) 5.7 V

3. The parallel combination of a 1.5 kΩ resistor and 470 Ω resistor is in series with the parallel combination of five 1 kΩ resistors. The source voltage is 50 V. The percentage of the load current through any single 1 kΩresistor is
(A) 25 %
(B) 20 %
(C) 100 %
(D) 50 %

Answer

Answer: (B) 20 %

4. On which of the following voltage range settings will a voltameter present minimum load on a circuit?
(A) 1 V
(B) 50 V
(C) 500 V
(D) 1,000 V

Answer

Answer: (D) 1,000 V

5. A Voltage divider consists of two 68 kΩ resistors and a 24 V source. The unknown output voltage is
(A) 12 V
(B) 24 V
(C) 0 V
(D) 6 V

Answer

Answer: (A) 12 V

6. Two 3.3 kΩ resistors are in series combination are in parallel with a 4.7 kΩ resistor. What will be the voltage across the 4.7 kΩ resistors if the voltage across one of the 3.3 kΩ resistors is 12 V
(A) 24 V
(B) 12 V
(C) 0 V
(D) 6 V

Answer

Answer: (A) 24 V

7. The 1.2 kΩ resistors are in series and this series combination is in parallel with a 3.3 3.3 kΩ resistor. The total resistance is
(A) 138 Ω
(B) 1,389 Ω
(C) 5,700 Ω
(D) 880 Ω

Answer

Answer: (B) 1,389 Ω

8. A certain voltage divider consists of three 1 kΩ resistors in series. Which of the following load resistors will have the least effect on the output voltage?
(A) 1 MΩ
(B) 100 kΩ
(C) 1 kΩ
(D) 330 Ω

Answer

Answer: (A) 1 MΩ

9. A certain Wheatstone bridge has the following resistor values: R1= 10 kΩ, R2 = 720 Ω and R4 = 2.4 kΩ. The unknown resistance is
(A) 24 Ω
(B) 2.4 Ω
(C) 300 Ω
(D) 3,000 Ω

Answer

Answer: (D) 3,000 Ω

10. In a certain five-step R/2R ladder network, the smallest resistor value is
(A) Indeterminable
(B) 2 kΩ
(C) 10 kΩ
(D) 20 kΩ

Answer

Answer: (B) 2 kΩ