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Physics M.C.Q (1 Marks)

Question Bank [ 2022 ] · Maharashtra Board STD 12 Science (MSBSHSE - English Medium). 117 questions.

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M.C.Q (1 Marks)

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MCQ 11 Mark
The decay constant λ of a certain radioactive material is 0.2166 per day. The average life τ of the radioactive material is ______ 
  • A
    5.332 days
  • ✓
    4.617 days
  • C
    2.166 days
  • D
    1.083 days
Answer
Correct option: B.
4.617 days
The decay constant λ of a certain radioactive material is 0.2166 per day. The average life τ of the radioactive material is 4.617 days.
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MCQ 21 Mark
In a single slit diffraction pattern, the first minima obtained with the red light of wavelength 6600 A.U. coincides with the first maxima f some other wavelength λ then is ______ 
  • A
    5500 A.U.
  • B
    5000 A.U.
  • C
    4800 A.U.
  • ✓
    4400 A.U.
Answer
Correct option: D.
4400 A.U.
In a single slit diffraction pattern, the first minima obtained with the red light of wavelength 6600 A.U. coincides with the first maxima f some other wavelength λ then is 4400 A.U.
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MCQ 31 Mark
For which logic gate the following statement is true The output is low, if and only if all inputs are low ______ >
  • A
    AND
  • B
    NOR
  • C
    NAND
  • ✓
    OR
Answer
Correct option: D.
OR
For which logic gate the following statement is true The output is low, if and only if all inputs are low OR.
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MCQ 41 Mark
The speed of electron having de Broglie wavelength of $10^{-10} m$ is $\left(m_e=9.1 \times 10^{-31} kg , h =6.63 \times 10^{-34} J - s \right)$
  • ✓
    $7.28 \times 10^6 m / s$
  • B
    $4 \times 10^6 m / s$
  • C
    $8 \times 10^5 m / s$
  • D
    $5.25 \times 10^5 m / s$
Answer
Correct option: A.
$7.28 \times 10^6 m / s$
The speed of electron having de Broglie wavelength of $10^{-10} m$ is $7.28 \times 10^6 m / s$.
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MCQ 51 Mark
Four resistances 4 Ω, 8Ω, XΩ and 12Ω are connected in a series to form Wheatstone’s network. If the network is balanced, the value of X is ______.
  • A
    24
  • ✓
    6
  • C
    12
  • D
    8
Answer
Correct option: B.
6
Four resistances 4 Ω, 8Ω, XΩ, and 12Ω are connected in a series to form Wheatstone’s network. If the network is balanced, the value of X is 6.
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MCQ 61 Mark
A parallel plate capacitor with oil between the plates (dielectric constant of oil, $k =2$ ) has a capacitance $C$. If the oil is removed, then the capacitance of the capacitor becomes
  • A
    $2 C$
  • B
    $C \sqrt{2}$
  • ✓
    $\frac{c}{\sqrt{2}}$
  • D
    $\frac{c}{2}$
Answer
Correct option: C.
$\frac{c}{\sqrt{2}}$
A parallel plate capacitor with oil between the plates (dielectric constant of oil, $k=2$ ) has a capacitance $C$. If the oil is removed, then the capacitance of the capacitor becomes $\frac{c}{2}$.
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MCQ 71 Mark
The bending of a beam of light around corners of obstacle is called ______ 
  • A
    Reflection
  • ✓
    Diffraction
  • C
    Refraction
  • D
    Interference
Answer
Correct option: B.
Diffraction
The bending of a beam of light around the corners of the obstacle is called Diffraction.
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MCQ 81 Mark
An organ pipe of length 0.4 m is open at both ends. The speed of sound in the air is 340 m/s. The fundamental frequency is ______ 
  • A
    405 Hz
  • B
    415 Hz
  • ✓
    425 Hz
  • D
    435 Hz
Answer
Correct option: C.
425 Hz
An organ pipe of length 0.4 m is open at both ends. The speed of sound in the air is 340 m/s. The fundamental frequency is 425 Hz.
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MCQ 91 Mark
Two S.H.M.'s have zero phase difference and equal amplitudes A. The resultant amplitude on their composition will be
  • ✓
    $2 A$
  • B
    zero
  • C
    $\sqrt{2} A$
  • D
    $\sqrt{2 A }$
Answer
Correct option: A.
$2 A$
Two S.H.M.’s have zero phase difference and equal amplitudes A. The resultant amplitude on their composition will be 2 A.
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MCQ 101 Mark
Heating a gas in a constant volume container is an example of which process?
  • ✓
    isochoric
  • B
    adiabatic
  • C
    isobaric
  • D
    cyclic
Answer
Correct option: A.
isochoric
isochoric
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MCQ 111 Mark
Calculate the energy radiated in one minute by a blackbody of surface area $200 cm ^2$ at $127^{\circ} C (\sigma=5.7 x$ $10^{-8} J m ^{-2} s ^{-1} K ^{-4}$ )
  • A
    $1367.04 J$
  • B
    $1698.04 J$
  • ✓
    $1751.04 J$
  • D
    $1856.04 J$
Answer
Correct option: C.
$1751.04 J$
1751.04 J
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MCQ 121 Mark
Two stones with radii 1:2 fall from a great height through the atmosphere. Their terminal velocities are in the ratio ______ 
  • A
    $2: 1$
  • ✓
    $1: 4$
  • C
    $4: 1$
  • D
    $1: 2$
Answer
Correct option: B.
$1: 4$
Two stones with radii 1:2 fall from a great height through the atmosphere. Their terminal velocities are in the ratio of 1:4
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MCQ 131 Mark
In a transistor amplifier, $IC = 5.5 mA , IE = 5.6 mA$. The current amplification factor $\beta$ is ______ 
  • A
    45
  • B
    50
  • ✓
    55
  • D
    60
Answer
Correct option: C.
55
In a transistor amplifier, $I _{ C }=5.5 mA, I _{ E }=5.6 mA$. The current amplification factor $\beta$ is $5 5 .$.
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MCQ 141 Mark
In Hydrogen, the electron jumps from the fourth orbit to the second orbit. The wavenumber of the radiations emitted by an electron is_______
  • A
    $\frac{ R }{16}$
  • ✓
    $\frac{3 R }{16}$
  • C
    $\frac{5 R }{16}$
  • D
    $\frac{7 R }{16}$
Answer
Correct option: B.
$\frac{3 R }{16}$
In Hydrogen, the electron jumps from the fourth orbit to the second orbit. The wavenumber of the radiations emitted by an electron is $\frac{3 R }{16}$.
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MCQ 151 Mark
Planck's constant is $6.6 \times 10^{-34} Js$. The momentum of each photon is given radiation Is $3.3 \times 10^{-}$ ${ }^{29} kg / s$. The $\lambda$ of radiation is
  • A
    $2 \times 10^{10} m$
  • B
    $2 \times 10^7 m z$
  • C
    $2 \times 10^5 m$
  • ✓
    $2 \times 10^{-5} m$
Answer
Correct option: D.
$2 \times 10^{-5} m$
Planck's constant is $6.6 \times 10^{-34} Js$. The momentum of each photon is given radiation Is $3.3 \times 10^{-29} kg / s$. The $\lambda$ of radiation is $\underline{2 \times 10^{-5} m }$.
Explanation:
$\lambda=\frac{ h }{ p } $
$=\frac{6.6 \times 10^{-34}}{3.3 \times 10^{-29}} $
$=2 \times 10^{-5} m$
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MCQ 161 Mark
A coil of resistance $300 \Omega$ and inductance $1.0 H$ is connected across an alternating voltage of frequency $\frac{300}{2 \pi} Hz$, therefore phase difference between the voltage and current in the circuit is
  • A
    $180^{\circ}$
  • ✓
    $90^{\circ}$
  • C
    $45^{\circ}$
  • D
    $0^{\circ}$
Answer
Correct option: B.
$90^{\circ}$
A coil of resistance $300 \Omega$ and inductance $1.0 H$ is connected across an alternating voltage of frequency $\frac{300}{2 \pi} Hz$, therefore the phase difference between the voltage and current in the circuit is $4 5 ^{\circ}$.
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MCQ 171 Mark
A magnet is moved towards a coil (i) quickly (ii) slowly, then the induced e.m.f. is ______ 
  • ✓
    larger in case (i)
  • B
    smaller in case (i)
  • C
    equal to both the cases
  • D
    larger or smaller depending upon the radius of the coil
Answer
Correct option: A.
larger in case (i)
A magnet is moved towards a coil (i) quickly (ii) slowly, then the induced e.m.f. is larger in case (i).
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MCQ 181 Mark
A magnetic material of susceptibility $3 \times 10-4$, and magnetic intensity is $4 \times 10-4 Am -1$. Then The magnetization in the units of Am-1 is..........
  • ✓
    $12 \times 10^8$
  • B
    $1.33 \times 10^8$
  • C
    $0.75 \times 10^{-8}$
  • D
    $14 \times 10^{-8}$
Answer
Correct option: A.
$12 \times 10^8$
A magnetic material of susceptibility $3 \times 10^{-4}$, and magnetic intensity is $4 \times 10^{-4} Am ^{-1}$. Then The magnetization in the units of $Am ^{-1}$ is $12 \times 10^8$.
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MCQ 191 Mark
A circular loop of radius 0.0157 m carries a current 2 A. The magnetic field at the centre of the loop is ______  
  • A
    $1.57 \times 10^{-3} Wb / m ^2$
  • ✓
    $8.0 \times 10^{-5} Wb / m ^2$
  • C
    $2.0 \times 10^{-3} Wb / m ^2$
  • D
    $3.14 \times 10^{-1} Wb / m ^2$
Answer
Correct option: B.
$8.0 \times 10^{-5} Wb / m ^2$
A circular loop of radius 0.0157 m carries a current 2 A. The magnetic field at the centre of the loop is $8.0 \times 10^{-5} Wb / m ^2$
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MCQ 201 Mark
A string of length ℓ fixed at one end carries a mass m at the other. The string makes 2/π revolutions/sec around the vertical axis through the fixed end. The tension in the string is ______ 
  • A
    2 ml
  • B
    4 ml
  • C
    8 ml
  • ✓
    16 ml
Answer
Correct option: D.
16 ml
A string of length ℓ fixed at one end carries a mass m at the other. The string makes 2/π revolutions/sec around the vertical axis through the fixed end. The tension in the string is 16 ml.
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MCQ 211 Mark
If the potential gradient of a wire decreases, then its length ______  
  • A
    remains constant
  • B
    decreases
  • ✓
    increases
  • D
    none of the above
Answer
Correct option: C.
increases
If the potential gradient of a wire decreases, then its length increases.
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MCQ 221 Mark
You are given a number of capacitors labelled as 8μF - 250V. Find the number of capacitors needed to get an arrangement equivalent to 16μF - 1000V. 
  • A
    4
  • B
    16
  • ✓
    32
  • D
    64
Answer
Correct option: C.
32
32
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MCQ 231 Mark
Which of the following cannot produce two coherent sources?
  • A
    Lloyd’s mirror
  • B
    Fresnel biprism
  • C
    Young’s double-slit
  • ✓
    Prism
Answer
Correct option: D.
Prism
Prism
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MCQ 241 Mark
The integral multiple of fundamental frequencies are ______ 
  • A
    beats
  • B
    resonance
  • C
    overtones
  • ✓
    harmonics
Answer
Correct option: D.
harmonics
The integral multiple of fundamental frequencies are harmonics.
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MCQ 251 Mark
When the displacement of a simple harmonic oscillator is half of its amplitude, its P.E. is 3 J. Its total energy is ______ 
  • A
    6 J
  • ✓
    12 J
  • C
    15 J
  • D
    20 J
Answer
Correct option: B.
12 J
When the displacement of a simple harmonic oscillator is half of its amplitude, its P.E. is 3 J. Its total energy is 12 J.
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MCQ 261 Mark
The second law of thermodynamics deals with the transfer of ______ 
  • A
    work done
  • B
    energy
  • C
    momentum
  • ✓
    heat
Answer
Correct option: D.
heat
The second law of thermodynamics deals with the transfer of heat.
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MCQ 271 Mark
The molar specific heat of a gas at constant volume is 12307.69 J kg-1 K-1. If the ratio of the two specific heats is 1.65, calculate the difference between the two molar specific heats of gas. 
  • ✓
    $7999 J kg ^{-1} K ^{-1}$
  • B
    $7245 J kg ^{-1} K ^{-1}$
  • C
    $6890 J kg ^{-1} K ^{-1}$
  • D
    $4067 J kg ^{-1} K ^{-1}$
Answer
Correct option: A.
$7999 J kg ^{-1} K ^{-1}$
$7999 J kg ^{-1} K ^{-1}$
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MCQ 281 Mark
The energy stored in a soap bubble of diameter $6$ cm and $T = 0.04 N/m$ is nearly
  • ✓
    $0.9 \times 10^{-3} J$
  • B
    $0.4 \times 10^{-3} J$
  • C
    $0.7 \times 10^{-3} J$
  • D
    $0.5 \times 10^{-3} J$
Answer
Correct option: A.
$0.9 \times 10^{-3} J$
The energy stored in a soap bubble of diameter $6 cm$ and $T=0.04$ $N / m$ is nearly $0 . 9 \times 10^{-3} J$
Explanation:
Increase in surface area of the sphere is given by:
$A =4 \pi r^2$
Here, $r$ is the radius of the sphere and $A$ is the increase in the surface area.
The bubble contains two surfaces. So multiply Equation (i) by $2$
$A=2 \times 4 \pi r^2$
Substitute the value of $r=3 cm$ to find the value of the area.
$A=2 \times 4 \pi \times\left(3 cm \times \frac{1 m }{100 cm }\right)^2$
$A=0.023 m ^2$
The formula for stored energy is:
$E = T \times A$
Here, $T$ is the surface tension.
Substitute the value of $T=0.04 N / m$ and $A=0.023 m ^2$ to find the stored energy.
$E=T \times A $
$E=0.04 N / m \times 0.023 m ^2$
$E=0.9 \times 10^{-3} J$
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MCQ 291 Mark
For a transistor $\beta=75$ and $IE =7.5 mA$. The value of $\alpha$ is.......
  • A
    0.1
  • B
    0.66
  • C
    0.75
  • ✓
    0.98
Answer
Correct option: D.
0.98
For a transistor $\beta=75$ and $I _{ E }=7.5 mA$. The value of $\alpha$ is $0 . 9 8$.
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MCQ 301 Mark
The dimensions of Rydberg’s constant are ______ 
  • A
    $\left[M^0 L^1 T^0\right]$
  • ✓
    $\left[ M ^0 L ^{-1} T ^0\right]$
  • C
    $\left[M^0 L^1 T^1\right]$
  • D
    $\left[ M ^0 L ^{-1} T ^{-1}\right]$
Answer
Correct option: B.
$\left[ M ^0 L ^{-1} T ^0\right]$
The dimensions of Rydberg’s constant are $\left[M^0 L^{-1} T^0\right]$
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MCQ 311 Mark
Ultraviolet radiation of 6.2 eV falls on an aluminum surface (work function 4.2 eV). The kinetic energy in joules of the fastest electron emitted is ______ 
  • A
    $3.2 \times 10^{-21}$
  • ✓
    $3.2 \times 10^{-19}$
  • C
    $3.2 \times 10^{-1}$
  • D
    $3.2 \times 10^{-15}$
Answer
Correct option: B.
$3.2 \times 10^{-19}$
Ultraviolet radiation of 6.2 eV falls on an aluminum surface (work function 4.2 eV). The kinetic energy in joules of the fastest electron emitted is $3.2 \times 10^{-19}$
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MCQ 321 Mark
An electric bulb operates 10 V d.c. If this bulb is connected to an a.c. source and gives normal brightness, then the peak value of the source is ______ 
  • A
    141.4 V
  • ✓
    14.14 V
  • C
    1.414 V
  • D
    0.1414 V
Answer
Correct option: B.
14.14 V
An electric bulb operates 10 V d.c. If this bulb is connected to an a.c. source and gives normal brightness, then the peak value of the source is 14.14 V.
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MCQ 331 Mark
Two pure inductors each of self-inductance L are connected in series, the net inductance is ______  
  • ✓
    2L
  • B
    L
  • C
    L/2
  • D
    L/4
Answer
Correct option: A.
2L
Two pure inductors each of self-inductance L are connected in series, the net inductance is 2L.
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MCQ 341 Mark
What is the magnetization of a bar magnet having a length of $6 cm$ and the area of cross-section $5 cm ^2$ ?
  • A
    $1.2 \times 10^{-4} A / m$
  • ✓
    $3.3 \times 10^4 A / m$
  • C
    $1.25 \times 10^{-4} A / m$
  • D
    $3.3 \times 10^{-4} A / m$
Answer
Correct option: B.
$3.3 \times 10^4 A / m$
$3.3 \times 10^4 A / m$
Explanation:
$I =6 cm , \Delta=5 cm ^2, M =1 Am ^2$
$\text { magnetization }= $
$\frac{\text { Magnetic moment }}{\text { Volume }}=\frac{ Am ^2}{ m ^3}= Am ^{-1}$
$=\frac{1 Am ^2}{6 \times 5 cm ^3}=\frac{1 Am ^2}{30 \times 10^{-6} m ^3}=\frac{10^6}{30} Am ^{-1}$
$=\frac{1}{3} \times 10^5=0.33 \times 10^5=3.3 \times 10^4 Am ^{-1}$
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MCQ 351 Mark
The magnetic dipole moment of the current loop is independent of ______  
  • A
    number of turns
  • B
    area of loop
  • C
    current in the loop
  • ✓
    the magnetic field in which it is lying 
Answer
Correct option: D.
the magnetic field in which it is lying 
The magnetic dipole moment of the current loop is independent of the magnetic field in which it is lying.
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MCQ 361 Mark
A cyclist riding a bicycle at a speed of $14 \sqrt{3} m / s$ takes a turn around a circular road of radius $20 \sqrt{3} m$ without skidding. Given $g =9.8$ $m / s ^2$, what is his inclination to the vertical
  • A
    $30^{\circ}$
  • B
    $45^{\circ}$
  • ✓
    $60^{\circ}$
  • D
    $90^{\circ}$
Answer
Correct option: C.
$60^{\circ}$
A cyclist riding a bicycle at a speed of $14 \sqrt{3} m / s$ takes a turn around a circular road of radius $20 \sqrt{3} m$ without skidding. Given $g =9.8$ $m / s ^2$, what is his inclination to the vertical $\underline{ 6 }{ }^{\circ}$
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MCQ 371 Mark
When the null point is obtained in the potentiometer, the current is drawn from the ______
  • ✓
    main battery
  • B
    cell battery
  • C
    both main and cell battery
  • D
    neither main nor cell battery
Answer
Correct option: A.
main battery
When the null point is obtained in the potentiometer, the current is drawn from the main battery.
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MCQ 381 Mark
The work done in carrying a charge $Q$ once round a circle of radius $r$ with charge $q$ at the centre of the circle is
  • A
    $\frac{1}{4 \pi \varepsilon_0} \cdot \frac{Q}{r}$
  • B
    $\frac{Q \cdot q}{4 \pi \varepsilon_0 r}$
  • ✓
    Zero
  • D
    $\frac{Q \cdot q}{2 r}$
Answer
Correct option: C.
Zero
The work done in carrying a charge Q once round a circle of radius r with charge q at the centre of the circle is Zero.
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MCQ 391 Mark
The path difference between two waves meeting at a point is (11/4)λ. The phase difference between the two waves is ______
  • A
    11 π/4
  • ✓
    11 π/2
  • C
    11 π
  • D
    22 π
Answer
Correct option: B.
11 π/2
The path difference between two waves meeting at a point is (11/4)λ. The phase difference between the two waves is 11 π/2.
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MCQ 401 Mark
In the law of tension, the fundamental frequency of the vibrating string is, ______ 
  • A
    inversely proportional to the square root of tension
  • B
    directly proportional to the square of tension
  • ✓
    directly proportional to the square root of the tension
  • D
    inversely proportional to the density 
Answer
Correct option: C.
directly proportional to the square root of the tension
In the law of tension, the fundamental frequency of the vibrating string is directly proportional to the square root of the tension.
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MCQ 411 Mark
The maximum speed of a particle executing S.H.M. is 10 m/s and maximum acceleration is 31.4 m/s2. Its periodic time is ______ 
  • A
    1 s
  • ✓
    2 s
  • C
    4 s
  • D
    6 s
Answer
Correct option: B.
2 s
The maximum speed of a particle executing S.H.M. is 10 m/s and maximum acceleration is $31.4 m / s ^2$. Its periodic time is 2 s.
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MCQ 421 Mark
Choose the correct option. A gas in a closed container is heated with 10 J of energy, causing the lid of the container to rise 2m with 3N of force. What is the total change in energy of the system?
  • A
    10J
  • ✓
    4J
  • C
    – 10J
  • D
    – 4J
Answer
Correct option: B.
4J
4J

Explanation:

Write the equation from the first law of thermodynamics.

ΔU = Q – W

Write the expression of work done.

W = F × Δx

W = (3N) × (2m)

W = 6J

Substitute 10J for Q and 6J for W to find a change in energy.

ΔU = 10J – 6J

ΔU = 4J

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MCQ 431 Mark
Calculate the value of λmax for radiation from a body having a surface temperature of 3000 K. (b = 2.897 x 10-3 m K) 
  • A
    9935 Å
  • ✓
    9656 Å
  • C
    9421 Å
  • D
    9178 Å
Answer
Correct option: B.
9656 Å
9656 Å
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MCQ 441 Mark
Two capillary tubes of radii 0.6 cm and 0.3 cm are dipped in the same liquid. The ratio of heights through which the liquid will rise in the tubes is ______ 
  • A
    $2: 1$
  • ✓
    $1: 2$
  • C
    $4: 1$
  • D
    $1: 4$
Answer
Correct option: B.
$1: 2$
Two capillary tubes of radii 0.6 cm and 0.3 cm are dipped in the same liquid. The ratio of heights through which the liquid will rise in the tubes is 1:2
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MCQ 451 Mark
In a common base configuration, the transistor has an emitter current of 10 mA and a collector current of 9.8 mA. The value of base current is ______ 
  • A
    0.1 mA
  • ✓
    0.2 mA
  • C
    0.3 mA
  • D
    0.4 mA
Answer
Correct option: B.
0.2 mA
In a common base configuration, the transistor has an emitter current of 10 mA and a collector current of 9.8 mA. The value of the base current is 0.2 mA.Explanation:
Let $I _{ e } b _{ e }$ emitter current $I _{ b } b _{ e }$ base current and $I _{ c } b _{ e }$ collector current.
$I_e=I_b+I_c$
$10 mA=I_b+9.8 mA$
$>I_b=0.2 mA .$
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MCQ 461 Mark
For the hydrogen atom, the minimum excitation energy ( of n =2) is ______For the hydrogen atom, the minimum excitation energy ( of n =2) is ______
  • A
    3.4 e V
  • ✓
    10.2 eV
  • C
    13.6 eV
  • D
    – 10.2 eV
Answer
Correct option: B.
10.2 eV
For the hydrogen atom, the minimum excitation energy ( of n =2) is 10.2 eV.
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MCQ 471 Mark
The work function of a metal is 4.2 Ev. Its threshold wavelength will be ______ 
  • A
    4000 Å
  • B
    3500 Å
  • ✓
    2959 Å
  • D
    2500 Å
Answer
Correct option: C.
2959 Å
The work function of a metal is 4.2 Ev. Its threshold wavelength will be 2959 Å.
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MCQ 481 Mark
A parallel LC resonant circuit is used as ______ 
  • A
    a tunning circuit in a television receiver set.
  • B
    a transformer
  • C
    a rectifier
  • ✓
    a filter circuit
Answer
Correct option: D.
a filter circuit
A parallel LC resonant circuit is used as a filter circuit.
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MCQ 491 Mark
In the expression e = –dΦ/dt, the -ve sign signifies ______ 
  • A
    The induced emf is produced only when magnetic flux decreases
  • ✓
    The induced emf opposes the change in the magnetic flux
  • C
    The induced emf is opposite to the direction of the flux.
  • D
    The induced emf is independent of change in magnetic flux.
Answer
Correct option: B.
The induced emf opposes the change in the magnetic flux
In the expression e = –dΦ/dt, the -ve sign signifies the induced emf opposes the change in the magnetic flux.
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MCQ 501 Mark
Relative permeability of iron 5500, then its magnetic susceptibility will be ______ 
  • A
    $5500 \times 10^7$
  • B
    5501
  • ✓
    5499
  • D
    $5500 \times 10^{-7}$
Answer
Correct option: C.
5499
Relative permeability of iron 5500 , then its magnetic susceptibility will be $\underline{ 5 4 9 9 }$.
Explanation:
$
\chi_m=\left(\mu_r-1\right) \Rightarrow \chi_m=(5500-1)=5499
$
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