Advertisements
Advertisements
प्रश्न
Calculate the number of electrons constituting one coulomb of charge.
Advertisements
उत्तर
One electron possesses a charge of 1.6 × 10-19C, i.e., 1.6 × 10-19C of charge is contained in 1 electron.
∴ 1 C of charge is contained in `1/(1.6 xx 10^(-19))`
= 6.25 × 1018
= 6 × 1018
Therefore, 6 × 1018 electrons constitute one coulomb of charge.
APPEARS IN
संबंधित प्रश्न
Draw the electrical symbols of the following components and state its use:
Rheostat (variable resistance)
Why should the resistance of:
a voltmeter be very large?
An electric bulb of resistance 20 Ω and a resistance wire of 4 Ω are connected in series with a 6 V battery.
Draw the circuit diagram, and calculate:
(a) total resistance of the circuit.
(b) current through the circuit.
(c) potential difference across the electric bulb.
(d) potential difference across the resistance wire.
Consider the circuit given below:
(a) In which circuit are the lamps dimmest?
(b) In which circuit or circuits are the lamps of equal brightness to the lamps in circuit (i)?
(c) Which circuit gives out the maximum light?
The lamps in a house hold circuit are connected in parallel because:
(a) this way they required less current
(b) if one lamp fails the others remain lit
(c) this way they require less power
(d) if one lamp fails the other also fail
Calculate the equivalent resistance between A and B in the adjacent diagram.
Complete the following table. The first answer has been given as an example
| Quantity | Unit |
|
(a) Electrical potential Volt ( b) Resistance ( c) Power ( d) Energy ( e) Resistivity |
Volt ........ .......... ............ .............. |
An electric kettle has a heating element which is rated at 2 kW when connected to a 250 V electric supply. Calculate the
(a) Current which flows in the element when it is connected to a 250 V supply,
(b) Resistance of the filament,
(c) Heat produced in 1 minute by the element,
(d) Cost of running the kettle for 10 minutes a day for 30 days of the month, at the rate of Rs. 3.00 per unit.
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 |
An electric iron is rated 750 W, 230 V. Calculate the electrical energy consumed by the press in 16 hours.
What should I choose ___________________
b. for getting protection from electric current.
c. to measure the current in the circuit?
MCB is used to protect household electrical appliances.
Match the following:
| 1. | 1 mA | a. | series |
| 2. | 1 pA | b. | ohmmeter |
| 3. | Ammeter | c. | 10-6 ampere |
| 4. | Electrical resistivity | d. | 10-3 ampere |
Problems for practice:
If 5A current flows through a circuit, then convert the current in terms of microampere?
What are the effects of electric current?
