CIRCUIT THEORY

A pure capacitor connected across an A.C. voltage consumed 50 W. This is due to

• The capacitive reactance in ohms

• The current flowing in capacitor

• The size of the capacitor being quite

• The statement is incorrect

The period of a wave is

• The same as frequency

• Time required to complete one cycle

• Expressed in amperes

• None of the above

The r.m.s. value and mean value is the same in the case of

• Triangular wave

• Sine wave

• Half wave rectified sine wave

• Square wave

Poor power factor

• Reduces load handling capability of electrical system

• Results in more power losses in the electrical system

• Overloads alternators, transformers and distribution lines

• Results in all above

The safest value of current the human body can carry for more than 3 second is

• 25 mA

• 9 mA

• 4 mA

• 15 mA

In a pure resistive circuit

• Current lags behind the voltage by 90°

• Current leads the voltage by 90°

• Current can lead or lag the voltage by 90°

• Current is in phase with the voltage

When an alternating current passes through an ohmic resistance the electrical power converted into heat is

• Apparent power

• True power

• Reactive power

• None of the above

The power factor of a D.C. circuit is always

• Greater than unity

• Zero

• Less than unity

• Unity

Power factor of electric bulb is

• Unity

• Zero

• Lagging

• Leading

A heater is rated as 230 V, 10 kW, A.C. The value 230 V refers to

• Average voltage

• None of the above

• Peak voltage

• r.m.s. voltage