Physics (Part-V) (Railway)

• The SI unit of potential difference is volt.

• Induced potential difference is potential difference only: hence, its unit is volt only.

• According to the question, the other wire is of the same material having nine times the length and the same area of cross section. So, length is the only variable among the two wires.

• Since, resistance of a wire is directly proportional to its length, 9 times increase in length imply nine times increase in resistance.

• The image thus formed is highly diminished, point size, real and inverted.

• In other words, m = v/u, where m is magnification, v is the image distance and u i the object distance.

• So, according to the question, m= 10/30 = 1/3 cm

• It is based on the principle that when there is a motion of a conductor within a constant magnetic field, an electromotive force is generated in it due to which a current start flowing in it.

• When the lines of force that pass from the north to the south pole of a magnet are cut by a wire there is produced or induced in the wire current of electricity.

• The centre of curvature is the centre of the sphere of which the spherical mirror is a part of It.

• It is at the same distance from every part of the surface of the mirror.

• Most electric motors operate through the interaction be tween the motor's magnetic field and electric current in a wire winding to generate force in the form of torque applied on the motor's shaft.

• Electric fans, mixers, washing machines, etc, are some of the domestic appliances that have electric motor.

•S0, R = 4/2 = 2 Ω

• From Ohm's law, Current 1 = V/R = 5/2 =2.5 Ampere

• Because nichrome does not oxidize and burn easily at high temperature i.e.it has higher melting and boiling point than metals.

• Thus, it does not melt even when a large amount of heat is produced due to passage of current.

•  As light travels from air(rarer) to water (denser) medium, it bend towards the remains due to this lemon would appear larger.