#2601

315 A body at rest may have

(a) speed

(b) momentum

(c) velocity

(d) energy

Explanation: A body at rest can still possess energy (e.g., potential energy), so option D is correct.

#2602

A sample of an ideal gas may (i) expand adiabatically, or (ii) expand isothermally. The net flow of heat into the gas from the exterior is

(a) positive in each case

(b) zero in each case

(c) negative for (i) and positive for (ii)

(d) zero in (i) and positive for (ii)

Explanation: In adiabatic expansion (i) heat flow is zero; in isothermal expansion (ii) heat flows into the gas to compensate the work, so zero for (i) and positive for (ii).

#2603

A glass may not break when it falls to a carpeted floor because of the ______ to stop.

(a) Short time

(b) Long time

(c) Both a & b

(d) None of these

Explanation: A carpet increases the stopping time, reducing force and preventing breakage, so option B.

#2604

327. Which of the following sets of concurrent forces may be in equilibrium?

(a) F1 = 3 N, F2 = 5 N, F3 = 0 N

(b) F1 = 3 N, F2 = 5 N, F3 = 6 N

(c) F1 = 3 N, F2 = 5 N, F3 = 1 N

(d) F1 = 3 N, F2 = 5 N, F3 = 15 N

Explanation: Three concurrent forces can be in equilibrium if they satisfy the triangle inequality; 6 < 3 + 5 so option D can form a closed triangle.

#2605

External forces may or may not be _____

(a) Balanced

(b) Identical

(c) Opposite

(d) Contradictory

Explanation: External forces acting on a body can be balanced or unbalanced depending on the situation.

#2606

The magnitude of the resultant of two forces may be increased by

(a) increasing the angle between them

(b) drawing the parallelogram to represent them

(c) drawing the forces perpendicularly

(d) decreasing the angle between them

Explanation: Bringing two forces closer in direction (decreasing the angle) increases their vector sum, so decreasing the angle increases the resultant's magnitude.

#2607

A body in equilibrium may not have:

(a) Momentum

(b) Kinetic energy

(c) Acceleration

(d) Velocity

Explanation: A body in equilibrium has zero net force and therefore may not have acceleration (acceleration is zero).

#2608

Surface tension of a liquid may be defined as

(a) Surface energy per unit area

(b) Heat energy per unit area

(c) P.E. per unit area

(d) K.E. per unit area

Explanation: Surface tension is the surface energy per unit area (or work required to increase surface area), so option C is correct.

#2609

67. A body in equilibrium may not have:

(a) Momentum

(b) Velocity

(c) Acceleration

(d) Kinetic energy

Explanation: A body in equilibrium has zero acceleration; it may have velocity (dynamic equilibrium), so it 'may not have' acceleration.

#2610

Temperature of Argon kept in a vessel is raised by 1°C at constant volume. Heat supplied to the gas may be taken partly as translational and partly rotational kinetic energies. Their respective shares are

(a) 60%, 40%

(b) 40%, 60%

(c) 100%, zero

(d) 50%, 50%

Explanation: Argon is a monatomic gas, so all supplied heat at constant volume goes to translational degrees of freedom (100%) and none to rotational (0%).

#2611

Absolute zero may be regarded as the temperature at which

(a) all substances are solids

(b) all gases become liquids

(c) water freezes

(d) molecular motion in a gas would cease

Explanation: Absolute zero is defined as the temperature at which molecular motion would cease.

#2612

1. Surface tension may be defined as

(a) free surface energy per unit volume.

(b) the work done per unit area in increasing the surface area of a liquid under isothermal conditions.

(c) the work done per unit area in increasing the surface area of a liquid under adiabatic conditions.

(d) the work done per unit area in increasing the surface area of a liquid both under isothermal and adiabatic conditions.

Explanation: Surface tension is defined as work done per unit area to increase surface area under isothermal conditions (option A).

#2613

If a bar is made of copper whose coefficient of linear expansion is one and a half times that of iron, the ratio of the force developed in the copper bar to the iron bar of identical lengths and cross-sections, when heated through the same temperature range (Young's modulus for copper may be taken to be equal to that of iron) is

(a) 3/2

(b) 4/9

(c) 9/4

(d) 2/3

Explanation: Force developed ∝ YαΔT; with equal Y and ΔT, ratio = α_copper / α_iron = 1.5/1 = 3/2.

#2614

A light rod of length 2 m is suspended from the ceiling horizontally by means of two vertical wires of equal length tied to its ends. One wire is steel with cross-sectional area 1×10^-9 m^2 and the other is brass with cross-sectional area 2×10^-9 m^2. The position along the rod from the steel wire at which a weight may be hung to produce equal stress in both wires is

(a) 1.5 m

(b) 0.67 m

(c) 1.0 m

(d) 1.33 m

Explanation: Equal stress means tensions are proportional to areas (T_s/T_b = A_s/A_b = 1/2). Balancing torques: (1/2)T_b·x = T_b·(2−x) gives x = 4/3 ≈ 1.33 m from the steel end.

#2615

A child whose class is in a windowless room may have to be assigned to another class if he/she suffers from ____.

(a) Acrophobia

(b) Agoraphobia

(c) Claustrophobia

(d) None of these

Explanation: Claustrophobia is the fear of confined or enclosed spaces, so a windowless room could trigger this condition.

#2616

A paraprofessional may properly engage in all of the following activities except

(a) Assisting on parents night

(b) Conferring with parents about a child behaviour

(c) Making short answer tests

(d) None of these

Explanation: Paraprofessionals generally should not confer with parents about student behavior without a certified teacher present; such communications are typically handled by certified staff.

#2617

The light reflected by a plane mirror may form a real image

(a) If the rays incident on the mirror are diverging

(b) under no circumstances

(c) If the rays incident on the mirror are converging

(d) If the object is placed very close to the mirror

Explanation: A plane mirror can form a real image only if the incident rays on the mirror are already converging so that reflection brings them to a focus.

#2618

A LASER beam may be used to measure very large distance because it is

(a) unidirectional

(b) coherent

(c) monochromatic

(d) not absorbed

Explanation: Lasers are highly coherent, which allows precise interference and distance measurements over long ranges.

#2619

At what distance from a concave mirror of focal length 10 cm must an object be placed in order that an image double its size may be obtained?

(a) either 5 cm or 15 cm

(b) 5 cm only

(c) at 10 cm

(d) 15 cm only

Explanation: A concave mirror gives a magnification of 2 for an object at 15 cm (real inverted) and a virtual erect magnification 2 for an object at 5 cm, so both positions apply.

#2620

A diverging lens may not have

(a) positive focal length

(b) one plane surface

(c) one convex surface

(d) negative focal length

Explanation: A diverging lens always has a negative focal length, so it cannot have a positive focal length.

May 2025 Current Affairs MCQs & Solutions

315 A body at rest may have

A sample of an ideal gas may (i) expand adiabatically, or (ii) expand isothermally. The net flow of heat into the gas from the exterior is

A glass may not break when it falls to a carpeted floor because of the ______ to stop.

327. Which of the following sets of concurrent forces may be in equilibrium?

External forces may or may not be _____

The magnitude of the resultant of two forces may be increased by

A body in equilibrium may not have:

Surface tension of a liquid may be defined as

67. A body in equilibrium may not have:

Temperature of Argon kept in a vessel is raised by 1°C at constant volume. Heat supplied to the gas may be taken partly as translational and partly rotational kinetic energies. Their respective shares are

Absolute zero may be regarded as the temperature at which

1. Surface tension may be defined as

A child whose class is in a windowless room may have to be assigned to another class if he/she suffers from ____.

A paraprofessional may properly engage in all of the following activities except

The light reflected by a plane mirror may form a real image

A LASER beam may be used to measure very large distance because it is

At what distance from a concave mirror of focal length 10 cm must an object be placed in order that an image double its size may be obtained?

A diverging lens may not have