CBSE 12 Physics Question Paper-2017 by Pavan | Practice Test to Test Your Knowledge
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  3. CBSE 12 Physics Question Paper-2017
CBSE 12 Physics Question Paper-2017

CBSE 12 Physics Question Paper-2017

This mock test includes actual CBSE Class 12 Physics board exam questions from the year 2017, helping students understand exam trends and practice real paper formats

2025-08-04
Pavan Pavan
CBSE Class 12 Physics 2017 Grade 12

Duration

30 min

Questions

30

Marking

Negative

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Questions Preview

Does the charge given to a metallic sphere depend on whether it is hollow or solid? Give reason for your answer.

A
Yes, the charge depends on whether the sphere is hollow or solid.
B
No, the charge is independent of whether the sphere is hollow or solid.
C
The charge depends on the material of the sphere.
D
The charge depends only on the size of the sphere.

A long straight current carrying wire passes normally through the centre of a circular loop. If the current through the wire increases, will there be an induced emf in the loop? Justify.

A
Yes, there will be an induced emf due to the changing magnetic flux.
B
No, the current does not induce emf.
C
The induced emf will be zero due to constant magnetic field.
D
The induced emf will decrease with the increase in current.

At a place, the horizontal component of earth's magnetic field is B and the angle of dip is 60°. What is the value of the horizontal component of the earth's magnetic field at the equator?

A
B
B
Zero
C
B/2
D
B*√3

Name the junction diode whose I-V characteristics are drawn below:

A
Zener diode
B
Schottky diode
C
PN junction diode
D
Tunnel diode

How is the speed of electromagnetic waves in a vacuum determined by the electric and magnetic fields?

A
By the ratio of the electric field to the magnetic field.
B
By the magnitude of the electric field alone.
C
By the product of the electric and magnetic fields.
D
By the permeability and permittivity of the vacuum.

How does Ampere-Maxwell law explain the flow of current through a capacitor when it is being charged by a battery? Write the expression for the displacement current in terms of the rate of change of electric flux.

A
By considering the changing electric field as the source of displacement current.
B
By using the formula for current as I = V/R.
C
By using the Ohm’s law and the rate of voltage change.
D
By relating the displacement current to the rate of change of the magnetic field.

Define the distance of closest approach. An α-particle of kinetic energy 'K' is bombarded on a thin gold foil. The distance of the closest approach is 'r'. What will be the distance of the closest approach for an α-particle of double the kinetic energy?

A
The distance will be doubled.
B
The distance will remain the same.
C
The distance will decrease by half.
D
The distance will be halved.

Find out the wavelength of the electron orbiting in the ground state of hydrogen atom.

A
1.21 × 10^-10 m
B
2.57 × 10^-10 m
C
1.65 × 10^-10 m
D
1.50 × 10^-10 m

Define the magnifying power of a compound microscope when the final image is formed at infinity. Why must both the objective and the eyepiece of a compound microscope have short focal lengths? Explain.

A
Magnifying power is the ratio of the image size to the object size. Short focal lengths are needed for high magnification.
B
Magnifying power is the ratio of the object size to the image size. Short focal lengths are required for high power.
C
Magnifying power is irrelevant to the focal lengths, but short focal lengths increase the depth of field.
D
Magnifying power is the ratio of the object size to the lens size. Short focal lengths reduce the magnifying power.

Which basic mode of communication is used in satellite communication? What type of wave propagation is used in this mode? Write, giving reason, the frequency range used in this mode of propagation.

A
Microwave communication is used. Propagation involves line-of-sight, and the frequency range is in the GHz band.
B
Radio communication is used. Propagation is through ground waves, and the frequency range is in the MHz band.
C
Infrared communication is used. Propagation involves diffraction, and the frequency range is in the THz band.
D
Optical communication is used. Propagation occurs through fiber-optics, and the frequency range is in the PHz band.

Find the value of the phase difference between the current and the voltage in the series LCR circuit. Which one leads in phase: current or voltage?

A
The current leads the voltage.
B
The voltage leads the current.
C
There is no phase difference.
D
The phase difference is 90 degrees.

Write the two processes that take place in the formation of a p-n junction. Explain the formation of depletion region and barrier potential with the help of a diagram.

A
Diffusion of charge carriers and formation of depletion region.
B
Electron capture and recombination of holes.
C
Formation of electric field and ionization.
D
Drift current and diffusion current.

Obtain the expression for the cyclotron frequency. Can a deuteron and a proton be accelerated by a cyclotron with the same oscillator frequency? Justify your answer.

A
Yes, they can be accelerated at the same frequency because they have the same charge.
B
No, they cannot be accelerated at the same frequency because their mass differs.
C
Yes, they can be accelerated at the same frequency because the frequency is dependent on charge.
D
No, their frequency would depend on both charge and mass, so they need different frequencies.

How does one explain the emission of electrons from a photosensitive surface with the help of Einstein's photoelectric equation? Which metals will not emit electrons for radiation of wavelength 3300 A from a laser source placed 1 m away from these metals? What happens if the laser source is placed 50 cm away?

A
Metals with work functions less than the energy of the incident photons will emit electrons.
B
The emission depends on the wavelength, and the laser distance does not affect the emission.
C
The emission depends on both the work function and the intensity of the laser.
D
The metals Na and K will not emit electrons at 3300 A, but the emission will increase if the source is brought closer.

A resistance of R draws current from a potentiometer. The potentiometer wire, AB, has a total resistance of R. A voltage V is supplied to the potentiometer. Derive an expression for the voltage across R when the sliding contact is in the middle of the potentiometer wire.

A
V * R / (2 * R)
B
V * R / R
C
V * R / (R + R)
D
V / 2

Define the term 'amplitude modulation'. Explain any two factors which justify the need for modulating a low-frequency base-band signal.

A
Amplitude modulation is a method of varying the amplitude of a carrier wave. Modulation is needed to transmit the signal over long distances.
B
Amplitude modulation is the process of encoding information into a carrier signal. It allows better frequency spectrum use.
C
Amplitude modulation increases the frequency of the signal for better reception.
D
Amplitude modulation changes the phase of the signal for easier reception.

Find equivalent capacitance between A and B in the combination given below. Each capacitor is of 2 µF capacitance. If a dc source of 7 V is connected across AB, how much charge is drawn from the source and what is the energy stored in the network?

A
The equivalent capacitance is 4 µF, charge is 28 µC, and the energy stored is 0.098 J.
B
The equivalent capacitance is 2 µF, charge is 14 µC, and the energy stored is 0.049 J.
C
The equivalent capacitance is 6 µF, charge is 42 µC, and the energy stored is 0.196 J.
D
The equivalent capacitance is 8 µF, charge is 56 µC, and the energy stored is 0.245 J.

Derive the expression for the electric field at a point on the equatorial line of an electric dipole. Depict the orientation of the dipole in stable and unstable equilibrium in a uniform electric field.

A
The electric field is derived using the dipole moment and the distance from the point to the dipole. The dipole aligns with the field in stable equilibrium.
B
The electric field is calculated as E = k * (2p) / r^3, where p is the dipole moment and r is the distance. The dipole aligns with the field in unstable equilibrium.
C
The electric field is proportional to the square of the distance from the dipole. The dipole aligns opposite to the field in stable equilibrium.
D
The electric field is inversely proportional to the cube of the distance. The dipole aligns perpendicular to the field in both stable and unstable equilibrium.

A radioactive nucleus 'A' undergoes a series of decays. The mass number and atomic number of A₂ are 176 and 71, respectively. Determine the mass and atomic numbers of A and A₃. Write the basic nuclear processes underlying β+ and β− decays.

A
The mass number of A is 177, and the atomic number is 72. A undergoes β+ decay.
B
The mass number of A is 176, and the atomic number is 71. A undergoes β− decay.
C
The mass number of A is 175, and the atomic number is 71. A undergoes γ decay.
D
The mass number of A is 175, and the atomic number is 70. A undergoes α decay.

A ray of light incident on face AB of an equilateral glass prism shows minimum deviation of 30°. Calculate the speed of light through the prism. Find the angle of incidence at face AB so that the emergent ray grazes along the face AC.

A
Speed of light is 2 × 10^8 m/s. Angle of incidence for grazing ray is 45°.
B
Speed of light is 3 × 10^8 m/s. Angle of incidence for grazing ray is 60°.
C
Speed of light is 1.5 × 10^8 m/s. Angle of incidence for grazing ray is 30°.
D
Speed of light is 2.5 × 10^8 m/s. Angle of incidence for grazing ray is 50°.

For a CE-transistor amplifier, the audio signal voltage across the collector resistance of 2 kΩ is 2V. Given that the current amplification factor is 100, find the input signal voltage and base current, if the base resistance is 1 kΩ.

A
Input voltage is 0.02 V, base current is 0.02 mA.
B
Input voltage is 0.1 V, base current is 0.1 mA.
C
Input voltage is 0.2 V, base current is 0.2 mA.
D
Input voltage is 0.5 V, base current is 0.5 mA.

What is the principle of operation of a transistor amplifier? How does the transistor amplify the input signal?

A
A transistor amplifier works by controlling the output current with a small input current. It amplifies the signal by modulating the current flow through a load resistor.
B
A transistor amplifier works by amplifying the input voltage using a high-gain resistor. It amplifies the signal by altering the output voltage.
C
A transistor amplifier works by amplifying the input power using a capacitor. It increases the signal strength by reducing the impedance.
D
A transistor amplifier works by converting a high-frequency input signal into a low-frequency output. It amplifies the signal through electromagnetic induction.

What is the difference between alpha and beta radiation in terms of mass and charge?

A
Alpha particles have more mass and charge than beta particles.
B
Beta particles have more mass and charge than alpha particles.
C
Alpha particles have less mass and no charge, while beta particles have more mass and negative charge.
D
Alpha particles have no charge, and beta particles have a positive charge.

Explain the working of a cyclotron. How does the magnetic field affect the motion of the charged particles in a cyclotron?

A
The cyclotron uses an alternating electric field to accelerate particles. The magnetic field forces the particles to move in a circular path, increasing their speed with each cycle.
B
The cyclotron uses a constant electric field to accelerate particles. The magnetic field controls the particles' speed by changing their velocity.
C
The cyclotron accelerates particles using a high-voltage source, and the magnetic field helps in their linear motion.
D
The cyclotron accelerates particles with a uniform electric field. The magnetic field alters the particle's trajectory but does not change the speed.

What is the difference between the electric field produced by a point charge and the electric field produced by an electric dipole?

A
The electric field of a point charge is radial and decreases with the square of the distance, while the electric field of a dipole is dipolar and decreases with the cube of the distance.
B
The electric field of a point charge is non-radial, while the electric field of a dipole is radial.
C
The electric field of a point charge is dipolar, while the electric field of a dipole is spherical.
D
The electric field of a point charge is uniform, while the electric field of a dipole is non-uniform.

In the context of photoelectric effect, what happens when the frequency of incident light is below the threshold frequency?

A
No electrons are emitted, regardless of the intensity of the light.
B
Electrons are emitted with lower energy, but only if the intensity is high.
C
Electrons are emitted, but they have less energy than expected.
D
Electrons are emitted only if the light is of sufficient intensity.

What is the principle of operation of a transistor amplifier? How does the transistor amplify the input signal?

A
A transistor amplifier works by controlling the output current with a small input current. It amplifies the signal by modulating the current flow through a load resistor.
B
A transistor amplifier works by amplifying the input voltage using a high-gain resistor. It amplifies the signal by altering the output voltage.
C
A transistor amplifier works by amplifying the input power using a capacitor. It increases the signal strength by reducing the impedance.
D
A transistor amplifier works by converting a high-frequency input signal into a low-frequency output. It amplifies the signal through electromagnetic induction.

What is the difference between alpha and beta radiation in terms of mass and charge?

A
Alpha particles have more mass and charge than beta particles.
B
Beta particles have more mass and charge than alpha particles.
C
Alpha particles have less mass and no charge, while beta particles have more mass and negative charge.
D
Alpha particles have no charge, and beta particles have a positive charge.

Explain the working of a cyclotron. How does the magnetic field affect the motion of the charged particles in a cyclotron?

A
The cyclotron uses an alternating electric field to accelerate particles. The magnetic field forces the particles to move in a circular path, increasing their speed with each cycle.
B
The cyclotron uses a constant electric field to accelerate particles. The magnetic field controls the particles' speed by changing their velocity.
C
The cyclotron accelerates particles using a high-voltage source, and the magnetic field helps in their linear motion.
D
The cyclotron accelerates particles with a uniform electric field. The magnetic field alters the particle's trajectory but does not change the speed.

What is the difference between the electric field produced by a point charge and the electric field produced by an electric dipole?

A
The electric field of a point charge is radial and decreases with the square of the distance, while the electric field of a dipole is dipolar and decreases with the cube of the distance.
B
The electric field of a point charge is non-radial, while the electric field of a dipole is radial.
C
The electric field of a point charge is dipolar, while the electric field of a dipole is spherical.
D
The electric field of a point charge is uniform, while the electric field of a dipole is non-uniform.