Objective Questions Short notes Objective questions (Answers are given below) In a d.c. motor, undirectional torque is producedwith the help of(a) brushes (b) commutator(c) end-plates (d) both (a) and (b) The counter e.m.f. of a d.c. motor(a) often exceeds the supply voltage(b) aids the applied voltage(c) helps in energy conversion(d) regulates its armature voltage The … Read more
Objective Questions Short notes Objective questions (Answers are given below) LEDs are commonly fabricated from galliumcompounds like gallium arsenide and galliumphosphide because they(a) are cheap(b) are easily available(c) emit more heat(d) emit more light. A LED is basically a ………………. P-N junction.(a) forward-biased(b) reverse-biased(c) lightly-doped(d) heavily-doped. As compared to a LED display, the distinct advantageof … Read more
Objective Questions Short notes Objective questions (Answers are given below) For a silicon diode, the value of the forwardbiasvoltage typically(a) must be greater than 0.3 V(b) must be greater than 0.7 V(c) depends on the width of the depletionregion(d) depends on the concentration of majoritycarriers. When forward biased, a diode(a) blocks current(b) conducts current(c) has … Read more
Objective Questions Short notes Objective questions (Answers are given below) The total energy of a revolving electron in anatom can(a) have any value above zero(b) never be positive(c) never be negative(d) not be calculated. An atom is said to be ionised when any one ofits orbiting electron(a) Jumps from one orbit to another(b) is raised … Read more
MCQ ON ILLUMINATION Objective Questions Short notes Objective questions (Answers are given below) Candela is the unit of(a) flux(b) luminous intensity(c) illumination(d) luminance. The unit of illuminance is(a) lumen(b) cd/m2(c) lux(d) steradian. The illumination at various points on ahorizontal surface illuminated by the samesource varies as(a) cos3θ(b) cos θ(c) 1/r2(d) cos2 θ. The M.S.C.P. of … Read more