English Medium Class 10 - CBSE Question Bank Solutions for Science

State Fleming’s left-hand rule.

Which of the following correctly describes the magnetic field near a long straight wire?

State whether the following statement is true or false

The field at the centre of a long circular coil carrying current will be parallel straight lines.

When is the force experienced by a current-carrying conductor placed in a magnetic field largest?

Imagine that you are sitting in a chamber with your back to one wall. An electron beam, moving horizontally from back wall towards the front wall, is deflected by a strong magnetic field to your right side. What is the direction of magnetic field?

State the rule to determine the direction of a force experienced by a current-carrying straight conductor placed in a magnetic field which is perpendicular to it.

State Fleming’s left hand rule.

An electrical appliance has a resistance of 25 Ω. When this electrical appliance is connected to a 230 V supply line, the current passing through it will be:

(a) 0.92 A
(b) 2.9 A
(c) 9.2 A
(d) 92 A

When a 4 Ω resistor is connected across the terminals of a 12 V battery, the number of coulombs passing through the resistor per second is:

(a) 0.3
(b) 3
(c) 4
(d) 12

The substance having infinitely high electrical resistance is called:

(a) conductor
(b) resistor
(c) superconductor
(d) insulator

If the length of a wire is doubled by taking more of wire, what happens to its resistance?

Name the material which is the best conductor of electricity.

Name the material which is used for making the heating element of an electric iron.

How does the resistance of a pure metal change if its temperature decreases?

How does the presence of impurities in a metal affect its resistance?

Write down an expression for the resistance of a metallic wire in terms of the resistivity.

 Give one example to show how the resistance depends on the nature of material of the conductor.

Calculate the resistance of an aluminium cable of length 10 km and diameter 2.0 mm if the resistivity of aluminium is 27 × 10⁻⁸ Ωm. 

How does the resistance of a wire change when: 

 its length is tripled? 

How does the resistance of a wire change when:

 its diameter is tripled?