Physics Questions

Heat transfer through radiation takes place in form of electromagnetic waves mainly in the infrared region. It depends on nature of the body, its temperature and kind & extent of its surface.

This acceleeration denoted by letter g varies from place to place. Unless stated otherwise, it can be taken 9.8 m/s2.

Electrical Pressure is also called as Voltage. Voltage is measured in Volts.

Volt : A unit of electrical pressure or Voltage is called Volt.

One volt is the amount of pressure required to cause one ampere of current to flow against one ohm of resistance.

Voltage is also referred to as Electromotive Force or Electrical Potential or Electrical Pressure.

True, Air is a Mixture.

Air is considered as mixture for the following reasons ;

1. Air can be separated into its components like N2, O2 , Argon and CO2 by the process of fractional distillation of liquid air.

2. Air shows the properties of all the gases present in the atmosphere.
For example : Oxygen is good Supporter of combustion. Hence air also is good supporter of combustion.

3. Air does not have a fixed formula.

4. Air has a variable composition because air at different places contains different amount of gases.

5. Heat or Light energy is neither absorbed nor released when air is prepared physical by mixing required amount of gases .

6. Mixture does have fixed boiling Point. It holds good in case of liquid air.

A Slip ring is a ring in a dynamo or electric motor which is attached to and rotates with the shaft, passing an electric current to a circuit via a fixed brush pressing against it.

Slip rings are usually made of Phosphor Bronze.

Slip ring motors usually have a 'phase-wound' rotor. This type of rotor has a 3-phase, double-layer, distributed winding consisting of coils used in alternators. The rotor core is made up of steel laminations which have slots to accommodate formed 3-single phase windings.

The resistance of metallic conductors e.g, platinum, increases with rise of  temperature . The increase in temperature results in a decrease of current which can be recorded in a galvanometer if the conductor is included in an electrical circuit. Thus the temperature can be known; platinum resistance thermometer is used generally for accurate scientific work. When two dissimilar metals are joined at the ends, and these ends are subjected to a difference of temperature, a current flows through the metals. Greater the difference of temperature , greater the current. So the curent strength can form the basis for measuring the difference in temperature. And when one of these temperatures is known, we can calculate the other.

Electrical burns occur principally because of the heat generated by the flow of electrical current through the body.

Burns caused by electricity are divided into three types:

electrical burns,

arc burns, and

thermal contact burns.

Electrical burns can result when a person touches electrical wiring or equipment that is used or maintained improperly.

Siphon is a tube bent to form two legs of unequal length by which a liquid can be transferred from a reservoir and then down to a lower level of it.

Siphon will fail to work if, the level of the liquid in the two vessels are at the same height.