Cbse Term 1 Question Paper
Neeru2012-10-23T12:15:00
CLASS 10 ELECTRICITY
1. How much current will an electric heater coil draw from a 220 volt line, if the resistance of the heater coil is 40?
(1 Mark)
(Ans) Given, R= 40, V=220 V
We have the relation,
I = V/R
= 220/40 = 5.5 A
2. What is electric current?
(1 Mark)
(Ans) The rate of flow of charge per unit time through a conductor is called electric current.
3. What is the SI unit of electric current?
(1 Mark)
(Ans) The SI unit of electric current is ampere. It is denoted by the letter A.
4. What is the SI unit of electric charge?
(1 Mark)
(Ans) Coulomb is the SI unit of electric charge.
5. Which metal is the best conductor of electricity at room temperature?
(1 Mark)
(Ans) Silver is the best conductor of electricity at room temperature.
6. Metals conduct electricity. Why?
(1 Mark)
(Ans) The presence of large amount offree electrons which can move from one atom to another atom in metals makes them possible to conduct electricity.
7. How should the resistances be connected so that the equivalent resistance is increased?
(1 Mark)
(Ans) The resistances should be connected in series so that the equivalent resistance is increased.
8. The length of the wire is doubled, what is the change in its resistivity?
(1 Mark)
(Ans) There is no change in the resistivity since it only depends upon the type of material used.
9. The combination of resistances shown below has equivalent resistance equal to 12 ohm, what is the value of R?
(1 Mark)
(Ans)
Resistances are connected in series.So, the equivalent resistance ,(Req),of the circuit is given by,Req= 8 + R.............(1).Substituting the value of equivalent resistance in the above equation(1),we get, 12 = 8 + R R = 4ohm.
10. Why is tungsten metal used for making the filaments of electric bulbs?
(1 Mark)
(Ans) Tungsten metal is used for making the filaments of electric bulbs because of its high melting point.
11. There is change in the length of
CLASS 10 ELECTRICITY
1. How much current will an electric heater coil draw from a 220 volt line, if the resistance of the heater coil is 40?
(1 Mark)
(Ans) Given, R= 40, V=220 V
We have the relation,
I = V/R
= 220/40 = 5.5 A
2. What is electric current?
(1 Mark)
(Ans) The rate of flow of charge per unit time through a conductor is called electric current.
3. What is the SI unit of electric current?
(1 Mark)
(Ans) The SI unit of electric current is ampere. It is denoted by the letter A.
4. What is the SI unit of electric charge?
(1 Mark)
(Ans) Coulomb is the SI unit of electric charge.
5. Which metal is the best conductor of electricity at room temperature?
(1 Mark)
(Ans) Silver is the best conductor of electricity at room temperature.
6. Metals conduct electricity. Why?
(1 Mark)
(Ans) The presence of large amount offree electrons which can move from one atom to another atom in metals makes them possible to conduct electricity.
7. How should the resistances be connected so that the equivalent resistance is increased?
(1 Mark)
(Ans) The resistances should be connected in series so that the equivalent resistance is increased.
8. The length of the wire is doubled, what is the change in its resistivity?
(1 Mark)
(Ans) There is no change in the resistivity since it only depends upon the type of material used.
9. The combination of resistances shown below has equivalent resistance equal to 12 ohm, what is the value of R?
(1 Mark)
(Ans)
Resistances are connected in series.So, the equivalent resistance ,(Req),of the circuit is given by,Req= 8 + R.............(1).Substituting the value of equivalent resistance in the above equation(1),we get, 12 = 8 + R R = 4ohm.
10. Why is tungsten metal used for making the filaments of electric bulbs?
(1 Mark)
(Ans) Tungsten metal is used for making the filaments of electric bulbs because of its high melting point.
11. There is change in the length of