Which scientific principle is 'electric generator' based on:

To which country, scientist J.J Thomson belong?

An ideal heat engine exhosting heat at 27°C is to have 25%efficiency. It must take heat at: _______.

For a gas, r = 1.4 then atomicity, C_P, and C_V of the gas are _______.

Water is poured from a height of 10m into an empty barrel at the rate of 1 litre per second. If the weight of the barrel is 10 kg, the weight indicated at time t = 60 s will be _______.

The pulley in the diagram is smooth and light. The masses of A and B are 5 kg and 2 kg. The acceleration of the system is _______.

For a ball falling in a liquid with constant velocity, ratio of resistance force due to the liquid to that due to gravity is

What is the shape when a non-wetting liquid in displaced in a capillary tube?

If g is the acceleration due to gravity on the earth's surface, the gain in the potential energy of an object of mass m raised from the earth's surface to a height equal to the radius R of the earth,is

If three uniform spheres, each having mass M and radius r, are kept in such a way that each touches the other two, the magnitude of the gravitational force on any sphere due to the other two is

Young's modulus of a material has the same unit as

Elastic limit is equal to

At about 4°C, a certain amount of water has maximum

If there are no heat losses, the heat released by the condensation of x gram of steam at 100°C into water at 100 °C can be used to convert y gram of ice at 0 °C into water at 100 ⁰C. Then the ratio y : x is nearly

An empty vessel is partially filled with water. The frequency of vibration of air column in the vessel

A string is stretched between fixed points separated by 75.0 cm. It is observed to have resonant frequencies of 420 Hz and 315 Hz. There are no other resonant frequencies between these two. Then the lowest resonance frequency for this string is

The dimensions of energy per unit volume are the same as those of _____.

The density of a cube is measured by measuring its mass and the length of its sides. If the maximum errors in the measurement of mass and length are 3% and 2% respectively, then the maximum error in the measurement of density is _____.

A particle executing simple harmonic motion along y-axis has its motion described by the equation y = A sin (ωt) + B. The amplitude of the simple harmonic motion is

A particle executes simple harmonic motion between x = - A and x = + A. The time taken for it to go from 0 to \(A\over 2\) is T₁ and to go from \(A\over 2\) to A is T₂. Then

Equal masses (m each) are attached at the two ends of a string passing over two pulleys. Another mass is attached at the centre of the string. In order that there is no sag in the string, this mass should be

What is the dimensions of power:

The displacement of an object at any instant is given by x = 30 + 20 t², where x is in metres and t in seconds. The acceleration of the object will be

In case of a moving body

A sealed container with negligible thermal coefficient of expansion contains helium (a monoatomic gas). When it is heated from 300 to 600 K, the average kinetic energy of the helium atom is

Two vessels having equal volume contain molecular hydrogen at one atmosphere and helium at two atmosphere pressure respectively.If both samples are at the same temperature the mean velocity of hydrogen molecule is

A particle performing uniform circular motion has angular momentum L. If its angular frequency is doubled and its kinetic energy halved, then the new angular momentum is

A loaded spring gun of mass M fires a 'shot' of mass m with a velocity \(\vartheta \) at an angle of elevation \(\theta\). The gun is initially at rest on a horizontal frictionless surface. After firing, the centre of mass of the gun-shot system

A boy aims a gun at a target from a point, at a horizontal distance of 100 m. if the gun can impart a horizontal velocity of 500 ms^-1 to the bullet, the height above the target where he must aim his gun, in order to hit it is (Take g = 10 ms=^-2)

A plane is indined at an angle of 30° with horizontal. The magnitude of component of a vector \(\overset\rightarrow{A}\)=-10\(\hat{k} \) perpendicular to this plane is (here z-direction is vertically upwards