(English Medium) ICSE Class 10 - CISCE Question Bank Solutions for Physics

With reference to the diagram shown below calculate:

(i) The equivalent resistance between P and Q.
(ii) The reading of ammeter.
(iii) The electrical power between P and Q.

State other bigger units of electric power and express them in watt.

State (i) the S. I. unit, (ii) the household unit, of electrical energy. How are these units related?

An electric kettle is rated 3kW, 250V. What should be the current capacity of the fuse with it?

I ampere of current is passed through a resistor of resistance R ohm for time t second. Obtain expression for
(i) the electrical energy, and
(ii) the electrical power spent.

How can electric energy consumed by an electric appliance be calculated in kilowatt hour (kWh)?

What is the resistance of an appliance rated at V volt, P watt?

A family uses a light bulb of 100W, a fan of 100W, and a heater of 1000W, each for 8 hours a day. If the cost of electricity is Rs. 2 per unit, what is the expenditure to the family per day, on electricity?

Establish the relation that heat produced in a metallic conductor due to the flow of current is V²t/R joules, where V is the potential difference across the ends of the conductor, R its resistance and t is the time in second for which current flows.

Find the heat produced in joules when a current of 10 amperes flows through a connecting wire of resistance 2 × 10^-2 ohms and heating element of resistance 250 ohms for 2 seconds.

An electric lamp A of 40 W and another electric lamp B of 100 W are connected to 220 V supply. Calculate the ratio of their filament resistances?

Find the energy released by a current of 0.25 amperes flowing through a heater for 5 minutes. The p.d. is 230 V.

An electric iron is rated at 230 V, 750 W. What is its resistance? What maximum current can be passed through it?

An electric bulb is rated as 100W – 250V. What information does it convey? Calculate the resistance of its filament while glowing.

An electric bulb is rated as 100W – 250V. What information does it convey? Calculate the current through the filament of the bulb.

An Electric bulb is marked 100 W, 230 V. What find the energy consumed by the bulb in one hour.

An Electric bulb is marked 100 W, 230 V. What current does it take?

An Electric bulb is marked 100 W, 230 V. What how long would this lamp take to consume one unit of electricity?

Out of the three fuses with current ratings 5A, 10A, 15A, which one is to be connected in a geyser circuit marked 3 kW, 220V? Give reason for your answer.

The equation I²R seems to suggest that the rate of heating in a resistor is reduced if resistance decreases, whereas equation P = V²/R suggests just the opposite. How do you reconcile this problem?