Advertisements
Advertisements
Question
Who will spend more electrical energy? 500 W TV Set in 30 mins, or 600 W heater in 20 mins?
Advertisements
Solution
For T.V. set: Power = 500 W,
Time = 30 min = 30 × 60 s
∴ Energy = Power × time
E1 = 500 × 30 × 60 = 900 × 103 J
For Heater: Power = 600 W,
Time = 20 min = 20 × 60 s
∴ Energy (E2) = 600 × 20 × 60
= 720 × 103 J
Comparing E1 and E2, E1 > E2
∴ Energy spent by T.V. set (E1) is greater.
The energy consumed by the T.V. set is more than that consumed by the heater.
APPEARS IN
RELATED QUESTIONS
Redraw the circuit of question 1, putting in an ammeter to measure the current through the resistors and a voltmeter to measure the potential difference across the 12 Ω resistors. What would be the readings in the ammeter and the voltmeter?
Draw circuit symbols for variable resistance
Draw circuit symbols for
a battery of three cells
Tell the odd one out. Give a proper explanation.
How does the short circuit form?
Find the odd one out and justify it.
Fuse wire, M.C.B., Rubber Gloves, Generator
Observe the following figure which bulb get fuse?
Distinguish between a closed circuit and an open circuit, with the use of suitable labelled diagrams.
Answer the following question.
With the help of a suitable circuit diagram prove that the reciprocal of the equivalent resistance of a group of resistances joined in parallel is equal to the sum of the reciprocals of the individual resistances.
What is the potential difference?
Nowadays MCBs are used in homes, for stop the current in the circuit which suddenly increases.
Write scientific reason.
It is beneficial to carry electrical energy in AC form as it is carried over long distances.
______ is the device used to close or open an electric circuit.
The switch is used to close or open an electric circuit.
Draw the circuit diagram for the series connection.
Tabulate the different components of an electric circuit and their respective symbols.
Rahul wants to make an electric circuit. He has a bulb, two wires, a safety pin, and a piece of copper. He does not have any electric cell or battery. Suddenly he gets some idea. He uses lemon instead of a battery and makes a circuit. Will the bulb glow?
In the circuit shown, which switches (L,M or N) must be closed to light up the bulb?
Draw the circuit diagram for the following series connection
Which of the following a simple circuit must-have?
_____ has a thin metallic filament that melts and breaks the connection when the circuit is overheated.
What is electric circuit?
When a circuit is open, _____ cannot pass through it.
Explain about domestic electric circuits. (circuit diagram not required)
A device that is used to break an electric circuit is called ______.
In the following circuits (Figure), heat produced in the resistor or combination of resistors connected to a 12 V battery will be
 |
 |
 |
| (i) | (ii) | (iii) |
Choose the statement which is not correct in the case of an electric fuse.
In an electric circuit a fuse is a ______ ______ to prevent possible fire.
The ______ is a species of fish that can give electric shocks of up to six hundred fifty watts of electricity.
Paheli connected two bulbs to a cell as shown in the following figure.
She found that filament of bulb B is broken. Will the bulb A glow in this circuit? Give reason.
Boojho has a cell and a single piece of connecting wire. Without cutting the wire in two, will he be able to make the bulb glow? Explain with the help of a circuit diagram.
Write a short note on the different electrical circuits.
A complete circuit is left on for several minutes, causing the connecting copper wire to become hot. As the temperature of the wire increases, the electrical resistance of the wire
An electric motor rated 1100 W is connected to 220 V mains. Find:
- The current drawn from the mains,
- Electric energy consumed if the motor is used for 5 hours daily for 6 days.
- Total cost of energy consumed if the rate of one unit is 5.
