Q1
mcq
1 mark
A point charge $q_1$ exerts a force $F$ on another point charge $q_2$ when placed at a fixed distance. If another point charge $q_3$ is brought near $q_2$, the force on $q_2$ due to $q_1$ :
- A. increases
- B. decreases
- C. may increase or decrease
- D. does not change
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Q2
mcq
1 mark
Equipotential surfaces for an isolated point charge are ________ in shape.
- A. spherical
- B. planar
- C. cylindrical
- D. conical
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Q3
mcq
1 mark
Resistivity of a metal wire depends on its :
- A. area of cross-section
- B. length
- C. material
- D. volume
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Q4
mcq
1 mark
The following table lists magnetic fields due to different current configurations. Column – I lists the current configurations and Column – II lists expressions for magnetic fields. Symbols have usual meanings.
Column – I | Column – II
---|---
i) At a distance r from an infinitely long straight wire. | p) $B = \mu_0 nI$
ii) At the centre of a circular current loop of radius r. | q) $B = \frac{\mu_0 I}{2r}$
iii) At the centre of a current carrying solenoid. | r) $B = \frac{\mu_0 I}{2\pi r}$
Match the current configurations in Column – I with the correct magnetic field expressions in Column – II.
- A. (i) – (p), (ii) – (q), (iii) – (r)
- B. (i) – (r), (ii) – (q), (iii) – (p)
- C. (i) – (r), (ii) – (p), (iii) – (q)
- D. (i) – (q), (ii) – (r), (iii) – (p)
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Q5
mcq
1 mark
‘The net magnetic flux through any closed surface is zero’. This law is called
- A. Gauss’ law in electrostatics
- B. Gauss’ law in magnetism
- C. Ampere’s circuital law
- D. Faraday’s law of electromagnetic induction
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Q6
mcq
1 mark
Consider the following statements :
Statement – 1 : A.C. Generator works on the principle of electromagnetic induction
Statement – 2 : In an A.C. Generator , as the armature is rotated in a uniform magnetic field , the magnetic flux linked with the coil changes which induces an emf in the coil.
Among the above two statements :
- A. Both Statements are true
- B. Both Statements are false
- C. Statement-1 is true and Statement-2 is false
- D. Statement-1 is false and Statement-2 is true
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Q7
mcq
1 mark
The variation of voltage and current through an a.c. circuit with time is as shown in the figure. Along with the a.c. source, the circuit :
- A. has a series combination of resistance and capacitance
- B. has only inductance
- C. has only capacitance
- D. may have only resistance or may have a suitable series combination of inductance (L), capacitance (C) and resistance (R)
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Q7
mcq
When a.c. is passed through an a.c. circuit, it is observed that the voltage and the current are in phase. Along with the a.c. source, the circuit :
- A. has a series combination of resistance and capacitance.
- B. has only inductance.
- C. has only capacitance.
- D. may have only resistance or may have a suitable series combination of inductance (L), capacitance (C) and resistance (R).
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Q8
mcq
1 mark
Transformer cores are usually laminated. This is to reduce energy loss due to
- A. flux leakage
- B. winding resistance
- C. eddy currents
- D. hysteresis
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Q9
mcq
1 mark
‘Ampere-Maxwell Law’ is written as (symbols have usual meanings) :
- A. $\oint \vec{B} \cdot d\vec{l} = \mu_0 i + \mu_0 \epsilon_0 \frac{d\phi_E}{dt}$
- B. $\oint \vec{B} \cdot d\vec{l} = \mu_0 i + \epsilon_0 \frac{d\phi_E}{dt}$
- C. $\oint \vec{B} \cdot d\vec{l} = \mu_0 i$
- D. $\oint \vec{E} \cdot d\vec{l} = -\frac{d\phi_B}{dt}$
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Q10
mcq
1 mark
Final image of a real object formed by a compound microscope is ____________ with respect to the object.
- A. real, inverted and magnified
- B. virtual, erect and magnified
- C. virtual, erect and diminished
- D. virtual, inverted and magnified
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Q11
mcq
1 mark
Which one of the following statements is WRONG about interference of light?
- A. Light waves of same wavelength coming from two independent sources can be coherent and can produce interference
- B. When the path difference between two interfering waves is $n\lambda$, bright fringe is produced (Here $n = 0, 1, 2, ....$ and $\lambda$ is the wavelength of light)
- C. When the phase difference between two interfering waves is $(2n+1)\pi$, dark fringe is produced (Here $n = 0, 1, 2, ..)$
- D. In Young’s double slit experiment, dark and bright fringes are equally spaced
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Q12
mcq
1 mark
A ball is dropped from a certain height and it falls freely under gravity. During the fall, the de Broglie wavelength associated with it :
- A. keeps increasing
- B. keeps decreasing
- C. is zero
- D. may increase or decrease
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Q13
mcq
1 mark
In Rutherford’s α-ray scattering experiment, α-particles of specific energy are projected towards a thin gold foil. If the impact parameter for the α-particles is zero, the angle of scattering is
- A. $\theta = 0^\circ$
- B. $\theta = 90^\circ$
- C. $\theta = 180^\circ$
- D. $\theta = 45^\circ$
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Q14
mcq
Binding energy per nucleon of a nucleus is a measure of its
- A. radius
- B. mass
- C. volume
- D. stability
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Q15
mcq
The energy gap for silicon is :
- A. 0.72 eV
- B. 1.1 eV
- C. 3 eV
- D. 5 eV
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Q16
short answer
1 mark
An electric dipole placed in a uniform electric field experiences a net ____________.
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Q17
short answer
1 mark
Water is an example for __________ material.
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Q18
short answer
1 mark
When a ____________ rod is inserted into a coil, its self-inductance increases.
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Q19
short answer
1 mark
Polarization of light shows that light is a _________ wave.
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Q20
short answer
1 mark
Photoelectric effect is a/an _____________ effect.
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Q21
short answer
2 marks
Define electric potential energy of a system of charges. What happens to the potential energy of a system of two unlike charges when the distance between them is increased (assume there is no external electric field)?
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Q22
short answer
2 marks
List any two limitations of Ohm’s law.
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Q23
short answer
2 marks
Write the expression for Lorentz force and explain the terms.
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Q24
short answer
2 marks
State Lenz’s law. What is its significance?
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Q26
short answer
2 marks
How are focal length ($f$) and radius of curvature ($R$) of a spherical mirror related? What is the sign of focal length of a convex mirror?
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Q27
short answer
2 marks
Mention the conditions for total internal reflection.
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Q28
short answer
2 marks
An intrinsic semi conductor crystal is doped with pentavalent atoms has an electron concentration of $10^{22} \times 5 \text{ m}^{-3}$. If, at thermal equilibrium, the intrinsic concentration $n_i = 1.5 \times 10^{16} \text{ m}^{-3}$, find the hole concentration.
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Q29
short answer
3 marks
Mention three properties of electric field lines.
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Q30
long answer
3 marks
Derive the expression for the equivalent capacitance of two capacitors connected in parallel.
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Q31
long answer
3 marks
Explain with a circuit diagram, how a galvanometer can be converted into voltmeter.
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Q32
short answer
3 marks
Define the terms: a) Magnetization, b) Magnetic permeability and c) Magnetic susceptibility.
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Q33
long answer
3 marks
Derive the expression for motional emf induced in a rod moving in a uniform magnetic field.
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Q34
short answer
3 marks
When a light radiation of energy 3 eV falls on a metal surface, photoelectrons with a maximum kinetic energy 1 eV are emitted from the surface. Find the threshold frequency for the metal surface. (Given: Planck’s constant, $h = 6.63 \times 10^{-34} \text{ Js}$; Charge on the electron $e = 1.6 \times 10^{-19} \text{ C}$).
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Q35
short answer
3 marks
State the postulates of Bohr’s hydrogen atom model.
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Q36
short answer
3 marks
Write any three properties of nuclear force.
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Q37
long answer
5 marks
Derive the expression for the electric potential at a point due to a point charge.
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Q38
long answer
5 marks
Arrive at the condition for balance of a Wheatstone’s network using Kirchhoff’s rules.
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Q39
long answer
5 marks
Obtain the expression for the force per unit length between two infinitely long straight parallel current carrying conductors placed in vacuum. Hence define the unit ‘ampere’.
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Q40
long answer
5 marks
a) State Huygen’s principle. b) Prove Snell’s law of refraction using Huygen’s principle by considering refraction of a plane wave by a surface.
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Q41
long answer
5 marks
a) What is a rectifier? b) With the help of a circuit diagram, input and output waveforms, explain the working of a full wave rectifier.
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Q42
long answer
5 marks
A uniformly charged spherical shell of radius 10 cm has a surface charge density of $16 \text{ } \mu\text{cm}^{-2}$. Find the electric field due to the shell at a distance of a) 20 cm from the centre of the shell, b) 5 cm from the centre of the shell.
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Q42
long answer
5 marks
A uniformly charged spherical shell of radius $10\text{ cm}$ has a surface charge density of $16\ \mu\text{C m}^{-2}$. Find the electric field due to the shell at a distance of:
a) $20\text{ cm}$ from the centre of the shell.
b) $5\text{ cm}$ from the centre of the shell.
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Q43
long answer
5 marks
Two identical cells each of emf 15 V either connected in series or connected in parallel across an external resistance of $5 \text{ } \Omega$ produce the same current through the resistor. a) Calculate the value of internal resistance of the cell. b) Find the current through the external resistor in either case.
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Q44
long answer
5 marks
A series LCR circuit with $L = 0.5\text{ H}$ and $R = 100\ \Omega$ is connected to a $200\text{ V}, 50\text{ Hz}$ a.c. supply.
a) Calculate the value of capacitance of the capacitor that drives the circuit into resonance.
b) Find the value of voltage across the inductor at resonance.
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Q45
long answer
5 marks
An object of height $1\text{ mm}$ is kept perpendicular to the axis of a thin convex lens of power $+10\text{ D}$. The distance between the object and the lens is $15\text{ cm}$. Find the position and height of the image formed.
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