Class - X Physics Holidays H.W
- Draw a schematic diagram of a circuit consisting
of a cell of 1.5 V, 10 Ω resistor and 15 Ω resistors and a plug key, all
connected in series.
- A wire of resistivity ‘r’ is pulled to double
its length. What will be its new resistivity?
- What is meant by saying that the potential difference
between two points is 1V?
- What is electrical resistivity? In a series electrical
circuit comprising a resistor made up of a metallic wire, the ammeter reads 5
A. The reading of the ammeter decreases to half when the length of the wire is
doubled. Why?
- Calculate the resistance of a conductor, if the
current flowing through it is 0.2 A when the applied potential difference is
0.8 volt.
- If 12 J of work is done in moving 2 coulomb of electric
charge through a conductor, what is the potential difference at the ends of the
conductor?
- The resistance of a wire of length 80 cm and of uniform area of
cross-section 0.025 cm2, is found to be 1.50 ohm. Calculate specific
resistance of wire in SI units?
- What should be the length of nichrome wire of resistance 4.5Ω, if the length of similar wire is 60 cm and resistance 2.5 Ω?
- A charge of 5000 C flows through an electric circuit in 2.5
hours. Calculate the magnitude of current flowing through the circuit.
- A battery can supply a
charge of 2.5 × 103C. If the current drawn from the battery is 12.5
A, calculate the time in which battery will get discharged.
- What is the resistance of
(hot) electric arc lamp when it uses a current of 25 A, while working at 440 V?
- A current of 0.2 A flows
through a conductor of resistance 4.5 Ω. Calculate the p.d. at the endsof the conductor.
- A wire is 1.0 m long, 0.2
mm diameter has resistance of 20 Ω. Calculate the resistivity of material.
- Give reason why (a)
tungsten is used for making filament of electric lamps. (b) The elements of heating electrical appliances
are made up of an alloy rather than pure metal.
- Copper wire has
resistance R. If the length of the wire is doubled, find the new resistance in terms
of original resistance?
- A battery of 9 V is
connected in series with resistors of 0.2 Ω, 0.3 Ω, 0.4 Ω, 0.5 Ω and 12 Ω resistors. How much current would flow through the 12 Ω resistor?
- An electric iron draws a
current of 0.5 A, when the voltage is 200 V. Calculate the amount of electric charge flowing through it, in one
hour
- Name an instrument used
for measuring electric potential difference by drawing diagram showing how this
instrument is connected in an electric circuit. Why does not this instrument practically
consume any electric energy from the electric circuit
- (a) Why are conductors of electric heating devices, such as
toasters and electric iron made of an alloy, rather than pure metals (b) Why is an ammeter likely to burn, if connected in parallel?
- A piece of wire is redrawn
by pulling it, until its length is trebled. Compare the new resistance of wire with the original resistance.
