List of top Physics Questions

Two similar thin $equi-convex$ lenses, of focal length $f$ each, are kept coaxially in contact with each other such that the focal length of the combination is $F_1$. When the space between the two lenses is filled with glycerin (which has the same refractive index $(p = 1.5)$ as that of glass) then the equivalent focal length is $F_2$. The ratio $F_1$ : $F_2$ will be :
A soap bubble, blown by a mechanical pump at the mough of a tube, increases in volume, with time, at a constant rate. The graph that correctly depicts the time dependence of pressure inside the bubble is given by :
A copper rod of $88 \,cm$ and an aluminium rod of unknown length have their increase in length independent of increase in temperature. The length of aluminium rod is $(a_{C_{u}}=1.7 \times 10^{-5}\,K^{-1}$ and $\left.a_{A_{l}}=2.2 \times 10^{-5} K^{-1}\right)$
Find the magnetic field at point $P$ due to a straight line segment $AB$ of length $6\, cm$ carrying a current of $5\, A$. (See figure) ($\mu_0 \, = \, 4\pi \times \, 10^{-7} \, N-A^{-2})$
$\alpha$-particle consists of:
A cycle wheel of radius $0.5\, m$ is rotated with constant angular velocity of $10 \,rad/s$ in a region of magnetic field of $0.1\, T$ which is perpendicular to the plane of the wheel. The $EMF$ generated between its centre and the rim is,
A wave along a string has the following equation $y = 0.05 \sin (28t - 1.78x)\, m$ (where t is in seconds and x is in meters). What are the amplitude, (A) frequency (f) and wavelength $(\lambda)$ of the wave?
A block of mass 5 kg resting on a horizontal surface is connected by a cord, passing over a light frictionless pulley to a hanging block of mass $5\, kg$. The coefficient of kinetic friction between the block and the surface is 0.5. Tension in the cord is : $(g = 9.8 \,m/sec^2)$
A ball falling in a lake of depth 200 m shows 0.1% decrease in its volume at the bottom. The bulk modulus of the material of the ball is
The radius of gyration about an axis through the center of a hollow sphere with external radius a and internal radius b is
The $ C.G.S. $ unit of magnetic field at a point, due to Biot-Savart law is
An electric bulb is rated $ 220\, V $ and $ 100\, W $ . What is the power consumed by it when operated on $ 110\, V $ ?
Which o f the following is true with respect to Rogers spiral experiment?
A vehicle moving at $36\, km/hr$ is to be stopped by applying brakes in the next $5\, m$. If the vehicle weighs $2000\, kg,$ determine the average force that must be applied on it
An example for the best source of monochromatic light is
What is the electric field at the centroid of an equilateral triangle of side length $ r $ , carrying charge $ q $ at each corner?
A refrigerator is to maintain eatables kept inside at $ 9 $ degree Celsius. If the room temperature is $ 36 $ degree Celsius, then what is the coefficient of performance?
What will be the potential at the centre of the sphere when a hollow metal sphere of radius $ 10\, cm $ is charged such that the potential on its surface is $ 80\, volts $ ?
Molecular weight of oxygen is $ 32\, amu $ . At $ STP $ , volume of $ 1\, gm $ of oxygen is $ 700 \,cm^3 $ . What is the value of gas constant $ R $ ?
If the heat of $ 110\,\,J $ is added to a gaseous system, whose internal energy is $ 40\,\,J $ , then the amount of external work done is:
A $ 1000\, kHz $ carrier wave is modulated by an audio signal of frequency range $ 600-6000 \,Hz $ . What is the bandwidth of the channel?
When a light ray enters from oil to glass on oil glass interface. Velocity of light changes by a factor of: \(\left(\mu_{oil}=2,\,\mu_{glass}=\frac{3}{2}\right)\)
The dimensional formula of coefficient of viscosity can be expressed as $ M^a\, L^bT^c $ . What are the values of $ a $ , $ b $ and $ c $ .
Find the distance between two consecutive nodes if a string has tension 0.25 N, mass per unit length is 1 mg/m and frequency is 250 Hz.
Out of soft iron and steel which has more coercivity, less retentivity.