Group - A
1. Choose the most suitable answer from the following options.
(i) Which of the following is an active element in a circuit?
(a) Current source
(b) Resistance
(c) Inductance
(d) Capacitance
(ii) A circuit having neither any energy source nor emf source is called the ____ circuit?
(a) unilateral
(b) bilateral
(c) passive
(d) active
(iii) In a semiconductor, the movement of holes is due to
- Movement of electrons in conduction band
- Movement of holes in conduction band
- Movement of holes in valence band
- Movement of electronics in valance band
(iv) Which of the following statement is correct for transistor?
- Base region is of low resistivity material and heavily doped
- Collector region is of higher conductivity than emitter
- Emitter region is of high resistivity material and lightly doped
- Emitter region is of high resistivity material and heavily doped
(v) An ideal voltage source should have
- Large emf
- Small emf
- Zero resistance
- None of these
(vi) An operational amplifier is basically a
- Low gain ac amplifier
- High gain dc amplifier
- High gain Rc coupled amplifier
- Low gain transformer coupled amplifier
(vii) In ideal Op-amp has the following characteristics.
(a) Ri = ∞ , A = ∞ , Ro = 0
(b) Ri = o , A = ∞ , Ro = 0
(c) Ri = ∞ , A = ∞ , Ro = ∞
(d) Ri = o , A = o , Ro = ∞
(viii) The output of a 2 - input OR gate is zero only when its
(a) either input is 0
(b) Either input is 1
(c) both inputs are 1
(d) both inputs are 0
(ix) An AND gate
- implements logic addition
- Gives high output only when all inputs are low
- Is equivalent to a series switching circuit
- Is equivalent to a parallel switching circuit
(x) The conductance of electrical circuit is analogous in magnetic circuit by
(a) Flux
(b) Reluctance
(c) Permeance
(d) Relative permeability
(xi) The magnitude of induced emf in a conductor depends upon the
(a) Among of flux cut
(b) Rate of change of flux linkage
(c) Amount of flux linkage
(d) Flux density of their magnetic field
(xii) When a single turn coil rotates in a uniform magnetic field, at a uniform speed the induced emf will be
(a) Alternating
(b) Pulsating
(c) steady
(d) None of these
(xiii) In a magnetic material, hysteresis loss takes place primarily due to
(a) Flux density lagging behind
(b) Molecular Friction
(c) Its high retentivity
(d) Rapid reversal of its magnetization
(xiv) The power factor of a practical inductor is
(a) unity
(b) Zero
(c) Lagging
(d) Leading
(xv) Under the condition of resonance in R-L-C services circuit, the power factor of the circuits is
(a) 0.5 lagging
(b) 0.5 leading
(c) Unity
(d) Zero
(xvi) Total instantaneous power supplied by a 3 phase ac supply to a balanced R-C load is
(a) Zero
(b) Constant
(c) Pulsating with zero average
(d) Pulsating with non-zero average
(xvii) The flux created by the current following through the primary winding, induced emf in
- Primary winding only
- Secondary winding only
- Transformer core only
- Both Primary and secondary windings
(xviii) In an auto transformer, power is transferred through
- Conduction process only
- Induction process only
- Both conduction and induction process
- Mutual coupling
(xix) The armature current of a synchronous motor at no load
(a) Leads the applied voltage by 90°
(b) Lags behind the applied voltage by 90°
(c) Is in phase with applied voltage
(d) Zero
(xx) In an Induction meter, if the air gap is increased
(a) Its speed will reduce
(b) its efficiency will improve
(c) its power factor will reduce
(d) Its breakdown torque will reduce
