Current electricity questions | form six Physics

Sketch the diagram showing the variation of current with potential difference across the
following:
(i) Filament electric bulb.
(ii) Gas-filled diode.

Answer / Solution

UNSOLVED

A wire of diameter 0.1​mm and resistivity 1.69×10​^-8​Ω​m with temperature coefficient of
resistance of 4.3×10^-3​K^-1​ ​ was required to make a resistance.
(i) What length of the wire is required to make a coil with a resistance of 0.5Ω?
(ii) If on passing a current of 2​A the temperature of the coil in (i) above rises by 10°​C, ​
what error would arise in taking the potential drop as 1.0V? ​

Answer / Solution

UNSOLVED

What is meant by the following terms:
(i) Alternating current (a.c.).
(ii) Effective value of A.C.

Answer / Solution

UNSOLVED

A 60​volt , ​ 10​watt ​ lamp is to be run on 100​volt , ​ 60​Hz ​A.C. mains.
(i) Calculate the inductance of a choke coil required.
(ii) If a resistor is used in (i) above instead of choke, what will be the value of its
resistance?

Answer / Solution

UNSOLVED

An ​ LCR circuit with ​ R=70Ω in series with a parallel combination of ​ L=1.5​H and C=30μF is driven by a 230​V ​ supply with angular frequency of 300​rad/s. ​
(i) Find the power in put to the circuit.
(ii) At the frequency ​, how does the circuit respond?.

Answer / Solution

UNSOLVED