English Medium कक्षा १० - CBSE Question Bank Solutions

Calculate the total resistance of the circuit and find the total current in the circuit.

These consist of two statements – Assertion (A) and Reason (R). Answer these questions selecting the appropriate option given below:

Assertion: Silver bromide decomposition is used in black and white photography.

Reason: Light provides energy for this exothermic reaction.

How is the mode of action in beating of the heart different from reflex actions? Give four examples.

1. Identify the gasses evolved at the anode and cathode in the above experimental set up.
2. Name the process that occurs. Why is it called so?
3. Illustrate the reaction of the process with the help of a chemical equation.

State Ohm's Law. Represent it mathematically.

What is the resistance of a conductor through which a current of 0.5 A flows when a potential difference of 2V is applied across its ends?

You are provided with a resistor, a key, an ammeter, a voltmeter, four cells of 1.5 V each and few connecting wires. Using circuit components, draw a labelled circuit diagram to show the setup to study Ohm's law.

State the relationship between potential difference (V) across the resistor and the current (I) flowing through it. Also draw V-I graph, taking V on the X-axis.

Let the resistance of an electrical device remain constant, while the potential difference across its two ends decreases to one fourth of its initial value. What change will occur in the current through it? State the law which helps us in solving the above stated question. 

What is meant by resistance of a conductor ? Define its SI unit.

A metal nitrate 'A' on heating gives a metal oxide along with evolution of a brown coloured gas 'B' and a colourless gas, which helps in burning. Aqueous solution of 'A' when reacted with potassium iodide forms a yellow precipitate.

1. Identify 'A' and 'B'
2. Name the types of the reactions involved in the above statement.

The resistance of a resistor is reduced to half of its initial value. If other parameters of the electrical circuit remain unaltered, the amount of heat produced in the resistor will become ______.

What is observed when silver chloride is exposed to sunlight? Give the type of reaction involved.

How is electric current related to the potential difference across the terminals of a conductor?

Draw a labelled circuit diagram to verify this relationship.

Why should an ammeter have low resistance?

Vinita and Ahmed demonstrated a circuit that operates the two headlights and the two sidelights of a car, in their school exhibition. Based on their demonstrated circuit, answer the following questions.

1. State what happens when switch A is connected to:
   a) Position 2
   b) Position 3
2. Find the potential difference across each lamp when lit.
3. Calculate the current.
   a) in each 12 Ω lamp when lit.
   b) In each 4 Ω lamp when lit.
   OR
4. Show, with calculations, which type of lamp, 4.0 Ω or 12 Ω, has the higher power.

When lead nitrate is heated strongly in a boiling tube, two gases are liberated and a solid residue is left behind in the test tube.

1. Name the type of chemical reaction and define it.
2. Write the name and formula of the coloured gas liberated.
3. Write the balanced chemical equation for the reaction.
4. Name the residue left in the test tube and state the method of testing its nature (acidic/basic).

Why have reflex arcs evolved in animals? 

Write one equation for decomposition reactions where energy is supplied in the form of light.

Write one equation for decomposition reactions where energy is supplied in the form of electricity.

A solution of a substance ‘X’ is used for whitewashing.

1. Name the substance ‘X’ and write its formula.
2. Write the reaction of the substance ‘X’ named in the above formula with water.