**1.**Inductance of a coil Varies

- directly as the cross-sectional area of magnetic core
- directly as square of number of turns
- directly as the permeability of the core
- inversely as the length of the iron path
- as (a) to (d)

Correct answer: (E)

as (a) to (d)

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

- average voltage
- r.m.s. voltage
- peak voltage
- none of the above

Correct answer: (B)

r.m.s. voltage

**3.**A parallel AC. circuit in resonance will

- have a high voltage developed across each inductive and capacitive section
- have a high impedance
- act like a resistor of low value
- have current in each section equal to the line current

Correct answer: (B)

have a high impedance

**4.**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 big
- the statement is incorrect

Correct answer: (D)

the statement is incorrect

**5.**A pure inductance connected across 250 V, 50 Hz supply consumes 100 W. This consumption can be attributed to

- the big size of the inductor
- the reactance of the inductor
- the current flowing in the inductor
- the statement given is false

Correct answer: (D)

the statement given is false

**6.**A sine wave has a frequency of 50 Hz. Its angular frequency is _________ radian/second.

- 100 n
- 50 jt
- 25 JT
- 5 n

Correct answer: (A)

100 n

**7.**All definitions of power factor of a series R-L-C circuit are correct except

- ratio of net reactance and impedance
- ratio of kW and kVA
- ratio of J and Z
- ratio of W and VA

Correct answer: (A)

ratio of net reactance and impedance

**8.**All the rules and laws of D.C. circuit also apply to A.C. circuit containing

- capacitance only
- inductance only
- resistance only
- all above

Correct answer: (C)

resistance only

**9.**An A.C. voltage is impressed across a pure resistance of 3.5 ohms in parallel with a pure inductance of impedance of 3.5 ohms,

- the current through the resistance is more
- the current through the resistance is less
- both resistance and inductance carry equal currents
- none of the above

Correct answer: (C)

both resistance and inductance carry equal currents

**10.**Aphasoris

- a line which represents the magnitude and phase of an alternating quantity
- a line representing the magnitude and direction of an alternating quantity
- a coloured tag or band for distinction between different phases of a 3-phase supply
- an instrument used for measuring phases of an unbalanced 3-phase load

Correct answer: (A)

a line which represents the magnitude and phase of an alternating quantity