Advertisements
Advertisements
प्रश्न
What is the function of a step-up transformer?
उत्तर
Function of a step-up transformer is to increase the a.c. voltage and decrease the current.
APPEARS IN
संबंधित प्रश्न
How many milliamperes as there in 1 ampere?
Draw a circuit diagram to show how two 4 V electric lamps can be lit brightly from two 2 V cells.
Which effect of current is utilised in the working of an electric fuse?
Complete the following sentence:
A fuse is connected in ........... with the ......... wire.
60 joules of heat was dissipated in a resistor when 20 C flowed for 5 s. Calculate:
(a) P.d. across the resistor,
(b) Resistance of the resistor, and
(c) Average power dissipated in the resistor.
Fig. shows a 3 pin plug with the cover removed. The electric cable
connected to the plug contains 3 wires with colour coded insulation namely brown, blue and green.
- Identify each of the colour coded wires by stating to which of the
terminals A, B or C in the diagram they should be connected. - Identify the terminal through which no current passes in normal
circumstances. - What is the purpose of the earthed wire connected to an electric
appliance like an electric heater? Describe how it works.
An electric bulb is rated at 220 V, 100 W.
- What is its resistance?
- What safe current can be passed through it?
For current to flow, one needs art open circuit.