MCQ
Two identical wires have the same fundamental frequency of $400 Hz$. when kept under the same tension. If the tension in one wire is increased by $2\%$ the number of beats produced will be
- ✓$4$
- B$2$
- C$8$
- D$1$
✓
Answer
Correct option: A.
$4$
a
(a) $n \propto \sqrt T $ ==> $\frac{{\Delta n}}{n} = \frac{1}{2}\frac{{\Delta T}}{T}$
(a) $n \propto \sqrt T $ ==> $\frac{{\Delta n}}{n} = \frac{1}{2}\frac{{\Delta T}}{T}$
Beat frequency $ = \Delta n = \left( {\frac{1}{2}\frac{{\Delta T}}{T}} \right)\,n = \frac{1}{2} \times \frac{2}{{100}} \times 400 = 4$
Need a full question paper?
Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.
Explore more
Similar questions
Two metal wires of identical dimensions are connected in series. If $\sigma _1$ and $\sigma _2$ are the conductivities of the metal wires respectively, the effective conductivity of the combination is
→In sum and difference method in vibration magnetometer, the time period is more if
Two spheres $P$ and $Q$, of same colour having radii $8\;cm$ and $2\;cm$ are maintained at temperatures ${127^o}C$ and ${527^o}C$ respectively. The ratio of energy radiated by $P$ and $Q$ is
→When a rubber-band is stretched by a distance $x$, it exerts restoring force of magnitude $F=ax+bx^2$ where $a$ and $b$ areconstants. The work done in stretching the unstretched rubber-band by $L$ is
→The temperature of a gas is $-50^{\circ}\,C$. To what temperature the gas should be heated so that the rms speed is increased by $3$ times?
→Major product $(Q)$ of following reaction is :
→A ball is suspended on a thread from the ceiling of a car. The brakes are applied and the speed of car changes from $5\, m/sec$ to $5/3\, m/sec$ during the time interval of $3\, seconds$. The angle that the thread will deviate from vertical
→The graphs in figure show that a quantity $y$ varies with displacement $d$ in a system undergoing simple harmonic motion. Which graphs best represents the relationship obtained when $y$ is The total energy of the system
→How many times more intense is $90\,\, dB$ sound than $40\,\, dB$ sound?
→A lamp is hanging $1 \,m$ above the centre of a circular table of diameter $1\,m$. The ratio of illuminaces at the centre and the edge is
→