English Medium कक्षा १० - CBSE Question Bank Solutions for Science

Two wires of the same length and area made of two materials of resistivity ρ₁ and ρ₂ are connected in series to a source of potential V. The equivalent resistivity for the same area is:

If R₁ and R₂ be the resistance of the filament of 40 W and 60 W respectively operating 220 V, then:

The resistance of the hot filament of the bulb is about 10 times the cold resistance. What will be the resistance of 100 W-220 V lamps, when not in use?

What is the maximum resistance which can be made using five resistors each of `1/5` W?

If the current I through a resistor is increased by 100% (assume that temperature remains unchanged), the increase in power dissipated will be:

In an electrical circuit, two resistors of 2 Ω and 4 Ω respectively are connected in series to a 6 V battery. The heat dissipated by the 4 Ω resistor in 5 s will be ______.

The north pole of Earth’s magnet is in the ____________.

A current-carrying conductor is held in an exactly vertical direction. In order to produce a clockwise magnetic field around the conductor, the current should be passed in the conductor:

When a 4 Ω resistor is connected across the terminals of a 2 V battery, the number of coulombs passing through the resistor per second is:

The shape of the magnetic field lines produced by a current-carrying conductor is ____________.

Two electric bulbs have resistances in the ratio 1 : 2. If they are joined in series, the energy consumed in them is in the ratio:

A current flows in a wire running between the S and N poles of a magnet lying horizontally as shown in the figure below:

The force on the wire due to the magnet is directed ____________.

The strength of magnetic field around a current-carrying conductor is ____________.

When current is parallel to a magnetic field, then force experience by the current-carrying conductor placed in a uniform magnetic field is ____________.

Which of the following factors affect the strength of force experience by current-carrying conduct in a uniform magnetic field?

A magnetic field directed in north direction acts on an electron moving in east direction. The magnetic force on the electron will act ____________.

The direction of force on a current carrying conductor in a magnetic field is given by ____________.

Show how you would connect three resistors, each of resistance 6 Ω, so that the combination has a resistance of 4 Ω.

Identify the reducing agent in the following reactions

`4"NH"_3 + 5"O"_2 -> 4"NO" + 6"H"_2"O"`

Identify the reducing agent in the following reactions - 

`"H"_2"O" + "F"_2 -> "HF" + "HOF"`