It is more comfortable to wear white cloths in summer because
A copper ball of mass 100 gm is at a temperature T. It is dropped in a copper calorimeter of mass 100 gm, filled with 170 gm of water at room temperature. Subsequently, the temperature of the system is found to be 75°C. T is given by : (Given : room temperature = 30° C, specific heat of copper = 0.1 cal/gm°C
When a p.d is applied across a conductor, the electrons experience a force in?
A current of 5A is flowing at 220 V in the primary coil of a transformer. If the voltage produced in the secondary coil is 2200 V and 50% of power is lost, then the current in the secondary will be
Light from the star, Alpha Centauri, which is nearest to the earth after the sun, reaches the earth in
The magnitude of the weight is expressed in the units of?
Optical fibre works on the
Which instrument is used to measure sound under water ?
A fluorescent tube is preferred to an electric bulb because
At the center of earth dt R, value of “g”?
If the wire of uniform area of cross-section is cut into two equal parts, the resistivity of each parts will be?
Name of the instrument to measure atomspheric pressure ?
A body floats in water with 40% of its volume outside water. When the same body floats in an oil, 60% of its volume remains outside oil. The relative density of oil is
An external pressure P is applied on a cube at 0°C so that it is equally compressed from all sides. K is the bulk modulus of the material of the cube and is its coefficient of linear expansion. Suppose we want to bring the cube to its original size by heating. The temperature should be raised by :
A piece of ice is floating in a beaker containing water. When whole of the ice melts
Siphon will fail to work if
In Young's double slit experiment, a third slit is made in between the double slits. Then
When a body moves with a constant speed in a circle?
Current has a direction. By convention, current is in the direction that ___.
Which instrument is used to measure pressure of gases ?
If escape velocity from the earth’s surface is 11.2 km/sec. then escape velocity from a planet of mass same as that of earth but radius one fourth as that of earth is
Mercury is commonly used as a thermometric fluid rather than water because
Choose the incorrect option ?
Lognitudinal waves and Transverse waves are types of ?
If no external force acts on a system of bodies, the total linear momentum of the system of bodies remains constant. Which law states this ?
The maximum current that can be measured.by a galvenometer of resistance 400 is 10 mA. It is converted into a voltmeter that can read upto 50 V. The resistance to be connected in series with the galvanometer is (in ohm).
Which of the following describes the energy changes takes place when a steam engine drives a generator which lights a lamp?