Electric Circuits Answers

Which action causes the LED to light up during the day?
A) Replace the npn transistor with a pnp transistor.
B) Interchange the position of LDR and R
C) Interchange the position of LDR and RB
D) Increase the number of cells

If IC = 50 mA and IE = 52 mA, calculate the current gain of the transistor.
A) 1.04
B) 2.04
C) 25
D) 26

What will happen to the value of IC if IB is increased?
A) Increases
B) Decreases
C) Remains

Which of the following statements is true?
A) A large base current controls a small collector current.
B) When used as an amplifier, the input is connected across C and E.
C) Resistor R is to avoid the transistor from being spoilt.
D) Collector current will reach its maximum value once base current flows.

Which of the following is not a terminal for a transistor?
A) Collector
B) Emulator
C) Base
D) Emitter

Which statement about a transistor is true?
A) Acts as a half-wave rectifier
B) Has its own internal energy supply
C) Is used to rectify a.c. to d.c.
D) Functions as a current amplifier

What is the threshold frequency of metal if its work function is 4.0 eV and wavelength of 700nm is incident on it?

Capacitance of 3uf, 6uf, and 12uf are connected in series across a 350V supply.
Calculate 1: the equivalent circuit capacitance
2: the charge on each capacitor
3: the potential difference across each capacitor

Three identical coils, each of resistance 10ohm and inductance 42mh are connected in star to a 415v, 50hz, 3 phase supply determine a-phase impedance, b-line voltage, c-phase voltage, d-phase current, power factor, e-power dissipated

Two resisters of R1 = 100±3 Ω and R2 = 200±4 Ω are connected on series. Find the maximum absolute error, relative error and percentage error in the equivalent resistance of the combination