List of top Physics Questions

Match LIST I with LIST II

LIST I
Device

LIST II 
Purpose
AMicrophoneIUsed in vehicles to measure distance
BAudiometerIIFor measuring the force and velocity of
wind
C OdometerIIIConverts sound waves to electrical vibrations
DAnemometer IVMeasures intensity of sound
Choose the most appropriate answer from the options given below:
Match List I with List II
List IList II
(A) Rn22286 → Po21884(III) α particle
(B) Bi21483 → Po21484(I) β− particle
(C) Th23490 → U23492(I) β− particle
(D) Na2211 → Na2210(II) β+ particle
Brief exposure to the sound of minimum can damage ear drums of humans.
In a metallic conductor, under the effect of applied electric field, the free electrons of the conductor 
A source of sound is moving towards a stationary observer with $\left(\frac{1}{10}\right)^{\text{th}}$ the speed of sound. The ratio of apparent to real frequency is
Equation of simple harmonic progressive wave is given by $y=\frac{1}{\sqrt{a}}\sin(\omega t)\pm \frac{1}{\sqrt{b}}\cos(\omega t)$. Then the resultant amplitude of the wave is ($\cos 90^{\circ}=0$):
The power factor of an R-L circuit is $\frac{1}{\sqrt{2}}$. If the frequency of AC is doubled the power factor will now be
In an AC circuit, the current is $i=5 \sin(100t - \frac{\pi}{2})$ A and voltage is $e=200 \sin(100t)$ volt. Power consumption in the circuit is ($\cos 90^{\circ}=0$)
When a string of length 'l' is divided into three segments of length $l_{1}$, $l_{2}$ and $l_{3}$, the fundamental frequencies of three segments are $n_{1}$, $n_{2}$ and $n_{3}$ respectively. The original fundamental frequency 'n' of the string is
A closed organ pipe of length $L_{1}$ and an open organ pipe contain diatomic gases of densities $\rho_{1}$ and $\rho_{2}$ respectively. The compressibilities of the gases are same in both pipes, which are vibrating in their first overtone with same frequency. The length of the open organ pipe is (Neglect end correction)
A solid sphere rolls without slipping on an inclined plane at an angle $\theta$. The ratio of total kinetic energy to its rotational kinetic energy is
Two discs of same mass and same thickness (t) are made from two different materials of densities $d_{1}$ and $d_{2}$ respectively. The ratio of the moment of inertia $I_{1}$ to $I_{2}$ of two discs about an axis passing through the centre and perpendicular to the plane of disc is
A solid metallic sphere has a charge +3Q. Concentric with this sphere is a conducting spherical shell having charge -Q. The radius of the sphere is 'A' and that of the spherical shell is 'B' ($B>A$). The electric field at a distance 'R' ($A<R<B$) from the centre is ($\epsilon_{0} =$ permittivity of vacuum)
A seconds pendulum is placed in a space laboratory orbiting round the earth at a height '3R' from the earth's surface. The time period of the pendulum will be (R = radius of earth)
According to kinetic theory of gases, which one of the following statements is wrong?
The potential energy of charged parallel plate capacitor is $v_{0}$. If a slab of dielectric constant K is inserted between the plates, then the new potential energy will be
The rays of different colours fail to converge at a point after passing through a thick converging lens. This defect is called
In a thermodynamic process, there is no exchange of heat between the system and surroundings. Then the thermodynamic process is
The radii of two soap bubbles are $r_{1}$ and $r_{2}$. In isothermal condition they combine with each other to form a single bubble. The radius of resultant bubble is
The ratio of potential difference that must be applied across parallel and series combination of two capacitors $C_{1}$ and $C_{2}$ with their capacitance in the ratio 1: 2 so that energy stored in these two cases becomes same is
A gas at N.T.P. is suddenly compressed to $(\frac{1}{4})^{th}$ of its original volume. The final pressure in atmosphere is (Given $\gamma = \frac{3}{2}$ and $P = $ original pressure)
In a meter bridge experiment null point is obtained at $l$ cm from the left end. If the meter bridge wire is replaced by a wire of same material but twice the area of across-section, then the null point is obtained at a distance
In a single slit experiment, the width of the slit is doubled. Which one of the following statements is correct?
A long straight wire carrying a current of 25 A rests on the table. Another wire PQ of length 1 m and mass 2.5 g carries the same current but in the opposite direction. To what height ($h$) will wire PQ rise? ($\mu_0 = 4\pi \times 10^{-7}$ SI unit)}
The excess of pressure in a first soap bubble is three times that of other soap bubble. Then the ratio of the volume of first bubble to other is