**BASANT’S SCIENCE ACADEMY**

CLASS-X Date-07/05/10

CHAPTER-ELECTRICITY

ASSIGNMENT-3 Submission date-14/05/10

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- By what name
**(single ward) is**joule/coulomb called? - How much work is done
**when one coulomb of charge moves against a potential difference**of 1 volt? - Define electric current. How can you measure the magnitude of electric current?
- Is electric current a vector quantity?
- Does an ammeter have low or a high resistance?
- What is the direction of conventional current?
- Write symbols for the following: (a) Cell (b) Battery(c) Fixed resistance(d) Wires crossing without contact(e) Variable resistance(f) A wire joint
- Write symbols for the following: (a) Ammeter (b) Voltmeter (c) Galvanometer (d) Open switch (e) Closed switch
- How do we connect a voltmeter in a circuit?
- How do we connect an ammeter in a circuit?
- State the law, which relates the current in a conductor to the potential difference across its ends.
- State the factors on which the resistance of a conductor depends.
- What is the term for the reciprocal of resistance?
- What is the nature of the graph between I and V for a metallic conductor?
- Does Ohm's law hold for a(a) copper wire(b) liquid electrolyte(c) vacuum tube
- Does the resistance of a metal change when we raise the temperature of the metal?
- Name the slope of the graph between V and I at a given temperature.Figure 2
- Name the slope of the graph between I and V at a given temperature.
- What is the law of combination of resistances in series?
- What is the law of combination of resistances in parallel?
- What is the resistance between A and B in thefollowing networks?

- Given five equal resistances; each of the value 5 Ω (a) what is the maximum resistance that can be obtained from them?(b) What is the minimum resistance that can be obtained from them?
- How will you join three resistances; of values 4 Ω,4 Ω and 2 Ω to get an electric resistanceof 4 Ω?
- How can we connect four resistances; of values 4 Ω, 4 Ω, 4 Ω and 12 Ω to get an effective resistance of 6 Ω?
- The unit of resistance is ohm. What is the unit of conductance?
- Define electric power.
- Name the quantity which is the product of potential difference and current.
- Express power P in terms of I and R.
- Write various formulae for electric power.
- What does 220 V, 100 W written on an electrical appliance mean? What do you mean by power rating?
- Write the commercial unit of energy.Define one Kilowatt-hour.
- lKwh =___MJ.
- What do you mean by one unit of electrical energy?
- List some important effects of electric current.
- Write a formula for calculating the amount of heat (H) produced in a resistor of resistance R when a current I is passed through it for time t.

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