SSC JE 2014 Electrical question paper with solution(Morning-Shift)

A 3 1/2 (7/2) digits digital multimeter has three full digits that can change from 0 to 9 and a one-half digit that can change to either 0 or 1. That means 3 1/2 digits digital multimeter can show values from 0 to 1,999 or 0 to -1,999.

Speed time curve of urban and suburban service

 

In suburban service, the distance between two adjacent stop for the electric train is 1-8 Km while in urban service the distance between two adjacent stop is 1 km only therefore coasting period or deceleration period is longer in suburban service as compared to urban service

Quadrilateral speed time curve is used for urban and suburban service

A Capacitor Start Motors is a single phase Induction Motor that employs a capacitor in the auxiliary winding circuit to produce a greater phase difference between the current in the main and the auxiliary windings. Due to greater phase difference capacitor Start motors have very high starting torque for a single-phase AC motor.

Reverse biasing means, applying an external voltage that is opposite in direction to forward bias i.e connecting the positive terminal of the battery to the n-side of the diode and the negative terminal of the battery to the p-side of the diode.

Under reverse bias, the diode does not conduct when the applied voltage is changed. The current remains constant at a negligibly small value (in the range of microamps) for a long-range change in applied voltage.

• A repulsion motor is a type of electric motor for using on alternating current (AC). It was formerly used as a traction motor for electric trains.
• Repulsion motors are classified under single-phase motors. In repulsion motors, the stator windings are connected directly to the AC power supply and the rotor is connected to a commutator and brush assembly, similar to that of a direct current (DC) motor
• The starting torque of the repulsion start motor is 350 percent with a moderate starting current.
• It is usually applicable where starting period is of a long duration because of the high inertia of the load. such as the high-speed lift.

A linear circuit is an electric circuit in which circuit parameters (Resistance, inductance, capacitance, waveform, frequency, etc) are constant. In other words, a circuit whose parameters are not changed with respect to Current and Voltage is called Linear Circuit.

Whereas in a non-linear circuit the parameters (Resistance, inductance, capacitance, etc) is not constant, is called Non-Linear Circuit.

Example : – Diode,transistor,SCR , transformer, iron core, inductor etc

The level of magnetic flux established in a ferromagnetic core is a direct function of the permeability of the material.Ferromagnetic materials have a very high level of permeability, while nonmagnetic materials such as air, vacuum, and wood have very low levels of permeability

Junction point

A point where three or more branches meet is called a junction point.

Node

A point at which two or more elements are joined together is called a node. The junction points are also the nodes of the network.

The Graph plotted between the armature current Ia and field current If at no load the curve is obtained known as V Curve. Since the shape of these curves is similar to the letter “V”, thus they are called V curve of the synchronous motor.