Physics

The duration in which the displacement becomes half the amplitude in the case of a simple harmonic motion if its period is 12 second, is

A train of length 600 m is travelling with a velocity of 64 km/hr. The time taken by the train to cross clearly a bridge of 1 km will be

Which one of the following pairs of physical quantities has the same dimension?

A body of mass 1 kg is rotated in a horizontal circle of radius 50 cm. If F and v represent the centripetal force and the constant speed respectively, which one of the following expressions may be correct?

The root mean square (rms) speed of hydrogen molecule at STP is 2 km per second. The rms speed of oxygen molecule at 810°C is

Bolometer measures the

A temperature of 14°F is equivalent to

A myopic eye cannot see object beyond 1.5m. What power of lens will be required to correct this defect of vision?

The critical angle of glass water interface is

A diffraction grating has 5000 lines per cm. The maximum order visible with the radiation of wavelength 600nm in diffraction experiment is

Light travels through a glass plate of thickness t and refractive index n. If C is the velocity of light in vacuum, the time taken by light to travel this thickness is

Two charges of 2 μC and 4 μC are 1m apart. The electric field intensity is zero at a point between the charges. This point is approximately at a distance.

An open organ pipe can produce

Watt per ampere is the unit of

Two wires A and B of equal radii are drawn from the same material. Their lengths are 1m and 2m respectively. The resistivity of A is

When a capacitor is added in series in an LCR circuit, the impedance of the circuit

A cell of emf X if connected across a resistance R. The potential difference across the wire is measured as Y. The internal resistance of the cell should be

The ratio of wavelength of the first line of Lyman series to the first line of Balmer series is

If work function of a metal is 3.3 eV, the threshold frequency in photoelectric effect will be

A radioactive material of half-life 5 days has its initial mass of 1 kg. The amount decayed after 20 days will be.

A charged particle is undergoing a circular motion in a uniform magnetic field. The time period is independent of

Velocity of sound in at 330 m/s  at STP. Its value at 300K will nearly be

Time of flight T of a projectile is related to the horizontal range R by an equation $gT^2 = 2R$. the angle of projection (in degrees) is

An electron in a field of $1\text{ N C}^{-1}$ will have an approximate acceleration.

A bullet gets heated if stopped by a target. If its velocity is doubled the rise in temperature of the bullet will be

The dimensional formula for potential difference is

A stone is thrown vertically upward with a speed $u$ from the top of a tower reaches the ground with a speed of $3u$. The height of the tower

The acceleration of a particle in SHM is………......

An iron ball is heated. The percentage increase will be largest in...........

Two wires A and B are of the same material. Their lengths are in the ratio of 1:2 and diameters are in the ratio of 2:1. If they are pulled by the same force, their increase in length will be in the ratio

Water is flowing through a tube of non-uniform cross section. If the radius of the tube at the entrance and the exit is 3:2, then the ratio of velocity of liquid entering and leaving the tube is:

The thermodynamic process in which the pressure of the system remains constant is called...............

50 g of ice at -6°C is dropped into water at 0°C. How many grams of water freeze? Specific heat capacity of ice = $2000\,J\,kg^{-1}\,°C^{-1}$.

The image of an object placed at the focus of a concave mirror is at

The temperature of source and sink of Carnot engine are 400K and 300K respectively. What is its efficiency?

The refractive index of air with respect to glass is 2/3.The refractive index of diamond with respect to air is 12/5 Then the refractive index of glass with respect to diamond will be......

The focal length of a double convex lens for which radius of curvature of each surface is R will be... $(\mu = 1.5)$

Light of wavelength $7200 \AA$ in air has a wavelength in glass equal to... (Given refractive index of glass with respect to air = 1.5).

Three capacitors of capacitance $3\mu F, 9\mu F$ and $18\mu F$ are connected first in series and then in parallel. The ratio of equivalent capacitance in two cases $(C_s / C_p)$ will be

Three equal resistors each of resistance $r$ are connected to form a triangle. The equivalent resistance across any two corners of the triangle is...

The resistances of two lamps are in the ratio of 1:2. Their wattage will be in the ratio of

The energy stored in a 50mH inductor carrying a current of 4A is......

The alternating current in an LCR circuit is maximum when

A particle of mass $10^{-31} Kg$ is moving with a speed of $10^5\,m/s$. The de Broglie wavelength of the particle is...

Two waves of the same wavelength and amplitude amplitude interfere to give a minimum when their phase difference is

The mass of $\alpha$-particle is

Hard X-rays as compared to soft X-rays have

A common emitter transistor amplifier has a current gain of 50. If the load resistance is $4\,K\Omega$ and the input resistance is $500\,\Omega$. The voltage gain of the amplifier is...

A tube closed at one end has a length 1 meter. The air column in the pipe can resonate for sound of frequency... $(V = 320\,ms^{-1})$

A displacement wave is represented by $y = 0.25\sin(500t - 0.0025x)$, where y, t and x are in cm, second and meter respectively. The wavelength of wave is...