ICSE question bank

Every question in the vault, filterable by class, subject, chapter, topic, year, marks, difficulty, type and source. The filters live in the URL, so any view you build can be shared.

93 questions

ISC Class XII 2025
Class 12 · Physics
But it is observed that they are attracting each other. (A) In questions (i) to (vii) given below, choose the What change should the student make for the wires correct alternative (a), (b), (c) or (d). to repel each other? [1]
Given below are two statements marked, Assertion
and Reason. Read the two statements and choose E
the correct option. Figure 4 Figure 5
Assertion: Diffraction of light is difficult to observe
in everyday situations but can be observed in (a) In which of the two combinations, emf of the
laboratory conditions. battery is greater?
Reason: To produce diffraction of waves, size of an (b) When a resistor ‘R’ is connected between the
obstacle must be comparable to the wavelength of terminals P and Q, I1 and I2 are the currents
the waves. flowing through ‘R’ in Figure 4 and Figure 5
(a) Both Assertion and Reason are true and Reason I
respectively. Obtain the ratio 1 .
is the correct explanation for Assertion. I2
(b) Both Assertion and Reason are true but Reason
Assertion–reason
ISC Class XII 2025
Class 12 · Physics
5] (3) State how a nuclear reactor can be shut down in
A semiconductor diode has two types of
USEFUL CONSTANTS AND RELATIONS
semiconducting materials: ‘P’ type and ‘N’ type.
1. Speed of light c = 3 × 108 ms-1
What is the difference between them? in vacuum
Short answer
ISC Class XII 2025
Class 12 · Physics
2] why current flowing through secondary coil is greater than that in primary coil. [1] (i) Figure 6 below shows an electric circuit. 3A 4 Q 1 4A P R Core Primary coil Secondary coil 10 V (input) (output) E S Figure 6 Apply Kirchhoff’s laws to calculate: Figure 3 (a) current ‘I’ flowing through the 2 Ω resistor.
Name any one phenomenon where moving particles
is at 63 cm mark. Calculate the emf of the second cell.
behave like waves.
1 markNumerical
ISC Class XII 2025
Class 12 · Physics
3] solenoid. A parallel beam of light is travelling obliquely from OR an optically rarer medium to an optically denser (ii) An alternating emf E = 5.0 sin(314 t)V is applied to a medium. circuit containing a resistor connected in series with
Use Huygen’s wave theory to prove Snell’s law.  314t - 3  A.
 
Short answer
ISC Class XII 2025
Class 12 · Physics
3] 10 cm apart in vacuum. Calculate magnetic field (B)
Harry sets up a circuit as shown in Figure 7 below. at the point X shown in Figure 8 below.
He measures potential difference ‘V’ across the P R
variable resistor R with an instrument Y. He also
measures current ‘I’ flowing through R with another I1 = 4A I2 = 16A
instrument X. 2 cm
Y X
10 cm
Q S
R
I Figure 8
X OR
Numerical
ISC Class XII 2025
Class 12 · Physics
3] (i) (a) Show that radius (rn) of the n Bohr orbit varies Two identical rectangular slits 5 mm apart are directly with square of the principal quantum illuminated with a monochromatic light of number (n) of the orbit. wavelength 600 nm. The screen is kept 1.2 m away (b) (1) Where does nuclear fusion reaction take place from the slits. continuously in the Universe?
What will be the change in the interference pattern
to Bhabha Atomic Research Centre, Mumbai. They
if the given light is replaced with monochromatic
visited various nuclear reactors like Apsara, Cirus,
light of wavelength 500 nm?
Zerlina and Dhruv and observed that Apsara was a
Short answer
ISC Class XII 2025
Class 12 · Physics
2] Satellite v(V) 2.5 2.0 1.5 1.0 0.5 Dish Antenna 0.1 0.2 0.3 0.4 0.5 i(A) (1) emf (E) of the cell.
Name the electromagnetic wave travelling from the
satellite to the dish antenna shown in the image (2) Internal resistance (r) of the cell.
above. OR
Short answer
ISC Class XII 2025
Class 12 · Physics
5] (3) State how a nuclear reactor can be shut down in
Draw a labelled diagram of a full wave rectifier.
2. Charge of a e = 1.6 × 10-l9C
Show graphically how its output voltage varies proton
with time.
3. Mass of a mρ = 1.67 × 10-27 kg
Diagram based
ISC Class XII 2025
Class 12 · Physics
2] why current flowing through secondary coil is greater than that in primary coil. [1] (i) Figure 6 below shows an electric circuit. 3A 4 Q 1 4A P R Core Primary coil Secondary coil 10 V (input) (output) E S Figure 6 Apply Kirchhoff’s laws to calculate: Figure 3 (a) current ‘I’ flowing through the 2 Ω resistor.
Hubble telescope employs a large parabolic mirror
Numerical
ISC Class XII 2025
Class 12 · Physics
2] If the position of the rod changes with time as x = πt, A convex lens having small focal length is to be used where x is in metre and t is in second, then: as a magnifying glass (simple microscope) to obtain (1) Calculate the motional emf developed in the an image of a small diamond. If the image lies at rod. least distance of distinct vision (D): (2) Name the law used to find the direction of
State any two characteristics of the image formed by from 15 A to 0 in 0.2 s, an emf of 30 V is induced in
the magnifying glass. it. Calculate the coefficient of self-inductance of the
Numerical
ISC Class XII 2025
Class 12 · Physics
5] (3) State how a nuclear reactor can be shut down in
What type of diode can be used as a voltage
proton
regulator?
4. Permeability μ0 = 4π × 10-7 Hm-1
of vacuum
5. 1 nm = 10-9m
6. π = 3.14

Short answer
ISC Class XII 2025
Class 12 · Physics
5] (3) State how a nuclear reactor can be shut down in
(a) Figure 9 shows a metallic rod AB of length case of an emergency.
l = 3 m moving in an (external uniform magnetic
(b) (1)
What is meant by the statement: ‘Angular
1 momentum of an orbiting electron is quantised’?
field, B =   T which is directed into the plane of
π (2) What is the physical significance of the fact that
this paper. total energy of an orbiting electron is negative?
B Question 20
When a television set (scientifically known as a
television receiver) is opened, many components
l V like semiconductor diodes, transistors, capacitors,
resistors, etc. can be observed on its motherboard.
There are different types of diodes like photo diode,
Zener diode, LED, etc. found in the T.V. set. With
A the help of these components, a television receives
Figure 9 audio as well as video signals.
5 marksLong answer
ISC Class XII 2025
Class 12 · Physics
3] 10 cm apart in vacuum. Calculate magnetic field (B)
An electron and a proton are moving along the +X
axis. If an external magnetic field B = 0.314 T is
E, r applied along -Z axis:
Figure 7 (a) What is the path followed by the electron due to
(a) Identify the instruments X and Y.
the magnetic field?
(b) Using the graph of V against I shown below,
(b) Calculate the frequency of revolution of the
calculate proton.
Numerical
ISC Class XII 2025
Class 12 · Physics
2] why current flowing through secondary coil is greater than that in primary coil. [1] (i) Figure 6 below shows an electric circuit. 3A 4 Q 1 4A P R Core Primary coil Secondary coil 10 V (input) (output) E S Figure 6 Apply Kirchhoff’s laws to calculate: Figure 3 (a) current ‘I’ flowing through the 2 Ω resistor.
In a potentiometer experiment, a cell of emf 1.25 V
as an objective. State any one advantage of using a
gives a balance point at 35 cm mark of the wire. If
mirror in place of a lens in such a telescope.
this cell is replaced by another cell, the balance point
1 markNumerical
ISC Class XII 2025
Class 12 · Physics
3] swimming pool type reactor. The teacher explained
Plot a labelled graph of stopping potential (VS) how water slows down fast moving neutrons and
versus frequency (f) of incident UV radiation. absorbs the heat produced in the reactor.
Diagram based
ISC Class XII 2025
Class 12 · Physics
3] swimming pool type reactor. The teacher explained
State how the value of Planck’s constant can be
(1) What is the use of a nuclear reactor?
determined from this graph.
(2) What is the name given to a material which
SECTION-D (15 MARKS) slows down fast moving neutrons?
Short answer
ISC Class XII 2025
Class 12 · Physics
2] different metallic wires A and B. J B With reference to photoelectric effect, define the terms:
Work function.
SECTION-C (27 MARKS)
E
Short answer
ISC Class XII 2025
Class 12 · Physics
2] is not the correct explanation for Assertion. In case of a short electric dipole: (c) Assertion is true and Reason is false.
Figure 3 below shows an ideal transformer. Explain
Assertion–reason
ISC Class XII 2025
Class 12 · Physics
2] why current flowing through secondary coil is greater than that in primary coil. [1] (i) Figure 6 below shows an electric circuit. 3A 4 Q 1 4A P R Core Primary coil Secondary coil 10 V (input) (output) E S Figure 6 Apply Kirchhoff’s laws to calculate: Figure 3 (a) current ‘I’ flowing through the 2 Ω resistor.
In an energy band diagram of a certain material, each of the current, number of turns of the coil and
forbidden band is absent. Identify this material. its radius is doubled.
SECTION-B (14 MARKS) Question 6
2 marksDiagram based
ISC Class XII 2025
Class 12 · Physics
3] (a) Which one of the wires, A or B, has higher An infinite plane metallic sheet having surface resistivity? charge density ‘+σ’ is placed in vacuum. P is a point (b) For a certain value of electric field (E), in which at a small distance ‘r’ to its right. wire ‘A’ or ‘B’ is drift velocity greater? Give a
Write an expression for intensity of electric field at
point P. reason for your answer.
Short answer