Paper 1 Superposition of Waves Drills

Q1

The principle of superposition states that when waves overlap, the resultant displacement is

A. the larger displacement only.
B. the vector sum of the individual displacements.
C. the product of the amplitudes.
D. always zero.

Q2

For two coherent waves of the same amplitude, constructive interference occurs when path difference is

A. $(n+\frac{1}{2})\lambda$.
B. $n\lambda$.
C. $\lambda /4$.
D. always zero only.

Q3

Destructive interference for two equal-amplitude coherent waves occurs when phase difference is

A. $0$.
B. $2\pi$.
C. $(2n+1)\pi$.
D. $4\pi$.

Q4

Coherent sources have a constant

A. amplitude only.
B. phase difference.
C. wavelength of zero.
D. intensity of zero.

Q5

In Young’s double-slit experiment, fringe spacing $x$ is given by

A. $x=\lambda D/a$.
B. $x=aD/\lambda$.
C. $x=\lambda a/D$.
D. $x=D/(a\lambda )$.

Q6

If double-slit separation is doubled with $D$ and $\lambda$ unchanged, fringe spacing

A. doubles.
B. halves.
C. quadruples.
D. is unchanged.

Q7

A stationary wave is formed by superposition of two waves with the same frequency and amplitude travelling

A. in the same direction.
B. in opposite directions.
C. at right angles.
D. with different speeds in the same medium.

Q8

At a node in a stationary wave, displacement amplitude is

A. maximum.
B. zero.
C. half maximum.
D. equal to wavelength.

Q9

Adjacent nodes in a stationary wave are separated by

A. $\lambda /4$.
B. $\lambda /2$.
C. $\lambda$.
D. $2\lambda$.

Q10

For a string fixed at both ends, the fundamental mode has length

A. $L=\lambda /4$.
B. $L=\lambda /2$.
C. $L=\lambda$.
D. $L=2\lambda$.

Q11

Single-slit diffraction becomes more pronounced when the gap width is

A. much larger than wavelength.
B. comparable to wavelength.
C. zero for all waves.
D. independent of wavelength.

Q12

For a single slit, the first minimum occurs approximately when

A. $a\sin \theta =\lambda$.
B. $d\sin \theta =n\lambda$.
C. $x=\lambda D/a$.
D. $v=f\lambda$.

Q13

For a diffraction grating, maxima satisfy

A. $d\sin \theta =n\lambda$.
B. $a\sin \theta =\lambda /2$.
C. $x=\lambda D/a$.
D. $T=1/f$.

Q14

The central maximum in a single-slit diffraction pattern is usually

A. narrower than all side maxima.
B. wider than side maxima.
C. absent.
D. always dark.

Q15

Increasing wavelength in a grating experiment with fixed spacing makes a given order appear at

A. smaller angle.
B. larger angle.
C. the same angle.
D. zero angle only.

Q16

The Rayleigh criterion concerns

A. terminal speed.
B. resolution of two sources.
C. internal resistance.
D. thermal equilibrium.

Q17

Interference changes the local resultant amplitude but not the waves’

A. frequency.
B. displacement.
C. resultant intensity.
D. phase relation.

Q18

In a stationary wave, energy is

A. transported steadily along the pattern.
B. not transferred along the string on average.
C. created at antinodes.
D. destroyed at nodes.

Q19

For an open pipe at both ends, displacement antinodes occur at

A. both ends.
B. neither end.
C. one end only.
D. the centre only.

Q20

For two-source interference, a path difference of $3\lambda$ gives

A. constructive interference.
B. destructive interference.
C. no resultant wave.
D. antiphase sources necessarily.