(English Medium) ICSE Class 10 - CISCE Important Questions for Physics

A cell of Emf 2 V and internal resistance 1.2 Ω is connected with an ammeter of resistance 0.8 Ω and two resistors of 4.5 Ω and 9 Ω as shown in the diagram below:

1) What would be the reading on the Ammeter?

2) What is the potential difference across the terminals of the cell?

What is consumed using different electrical appliances, for which electricity bills are paid?

Find the equivalent resistance between points A and B

Two resistors of 4Ω and 6 Ω are connected in parallel to a cell to draw 0.5 A current from the cell.
(i) Draw a labelled circuit diagram showing the above arrangement.
(ii) Calculate the current in each resistor. What is an Ohmic resistor?

What is an Ohmic resistor?

Two copper wires are of the same length, but one is thicker than the other. Which wire will have more resistance?

(i) Two sets A and B, of three bulbs each, are glowing in two separate rooms. When one of the bulbs in set A is fused, the other two bulbs also cease to glow. But in set B, when one bulb fuses, the other two bulbs continue to glow. Explain why this phenomenon occurs.

(ii) Why do we prefer arrangements of Set B for house circuiting?

You have three resistors of values 2Ω, 3Ω and 5Ω. How will you join them so that the total resistance is more than 7Ω?

1) Draw a diagram for the arrangement

2) Calculate the equivalent resistance.

Name two safety devices which are connected to the live wire of a household electric circuit

Find the equivalent resistance between A and B

State whether the resistivity of a wire changes with the change in the thickness of the wire.

How does an increase in the temperature affect the specific resistance of a : 
(i) Metal and
(ii) Semiconductor ?

Calculate the effective resistance across AB?

The diagram above shows a circuit with the key k open. Calculate :
(i) the resistance of the circuit when the key k is open.
(ii) the current drawn from the cell when the key k is open.
(iii) the resistance of the circuit when the key k is closed.
(iv) the current drawn from the cell when the key k is closed.

The diagram below shows a magnetic kept just below the conductor AB which is kept in North South direction.

(i) In which direction will the needle deflect when the key is closed ?
(ii) Why is the deflection produced ?
(iii) What will be the change in the deflection if the magnetic needle is taken just above the conductor AB ?
(iv) Name one device which works on this principle.

(a) Calculate the total resistance across AB.

(b) If a cell of e.m.f 2.4 V with negligible internal resistance is connected across AB then calculate the current drawn from the cell.

(a) Observe the diagram given below and state whether the bulb will glow or not when we switch on K.

(b) Is it safe to handle the bulb when the switch is OFF?

(c) Give a reason for your answer in (b).

An electric bulb is rated ‘240 V, 100 W’.

1. What information can you get from the above statement?
2. What will happen if this bulb is connected across 220 V?
3. Calculate the resistance of the bulb.
4. Also find the energy consumed by the bulb in 10 minutes.

When a current I flows through a wire of resistance R for time t then the electrical energy produced is given by ______.