Advertisements
Advertisements
Question
MCB is used to protect household electrical appliances.
Options
True
False
Advertisements
Solution
MCB is used to protect household electrical appliances - true.
APPEARS IN
RELATED QUESTIONS
Calculate the number of electrons constituting one coulomb of charge.
Three 2 V cells are connected in series and used as a battery in a circuit.
How many joules of electrical energy does 1 C gain on passing through (i) one cell (ii) all three cells?
If 20 C of charge pass a point in a circuit in 1 s, what current is flowing?
A 5 V battery is connected to two 20 Ω resistors which are joined together in series.
(a) Draw a circuit diagram to represent this. Add an arrow to indicate the direction of conventional current flow in the circuit.
(b) What is the effective resistance of the two resistors?
(c) Calculate the current that flows from the battery?
(d) What is the p.d. across each resistor?
Name two devices which work on the heating effect of electric current.
A charge of 80 C flows in a conductor for 2 minutes.
(a) Calculate the current flowing through the conductor.
(b) If the current through a heater is 4 A what charge must be passing in 8 seconds?
What would be the danger involved in replacing a blown fuse with the one which would carry a large current?
Explain with the help of a diagram how does 'short circuiting' occur in an electric kettle.
Electrical appliances have voltage and power ratings as listed below. Which
has the larger working resistance?
| Appliances | Voltage (V) | Power (W) |
| (a) Washing machine | 250 | 3000 |
| ( b) Television | 240 | 160 |
| (c)240 | 240 | 1500 |
| ( d) Hair curler | 250 | 20 |
| ( e) Car head lamp | 12 | 36 |
A 3 pin mains plug is fitted to the lead for a 1 kW electric kettle to be used on a 250 V A.C. supply. Which of the following statements is NOT correct?
(a) A 13 A fuse is the most appropriate value to use.
(b) The brown wire should be connected to the live side of the mains.
