# 10th Science Unit 4 Book Back Answer

## Samacheer Kalvi 10th Science Unit 4 Book Back Questions with Answers:

Samacheer Kalvi 10th Std  Science Book Back 1 Mark and 2 Mark Questions with Answers PDF in Science uploaded and available below. 10th Standard New Science Syllabus 2022 – Physics 4 Electricity Science Book Back Answers available for both English and Tamil mediums. Tamil Nadu Samacheer Kalvi 10th Science Book Portion consists of  23 Units. Science Book Contain Physics 01- 06, Chemistry 07 – 11, Biology 12 – 22 and Visual Communications  23 units. Check Unit-wise and Full Class 10th Science Book Back Answers/ Guide 2022 PDF format for Free Download for both English and Tamil Medium. Samacheer Kalvi 10th Science Book back Solutions/Answers below:

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Samacheer Kalvi 10th Science Book Subject One Mark, Two Mark Guide questions and answers are available below. Check Science Book Back Questions with Answers. Take the printout and use it for exam purposes.

### 10th Science Book Back Answers

#### Unit 4 – Electricity

1. Which of the following is correct?
a) Rate of change of charge is electrical power.      b) Rate of change of charge is current.
c) Rate of change of energy is current.                     d) Rate of change of current is charge.
Ans: b) Rate of change of charge is current

2. SI unit of resistance is
a) mho   b) joule   c) ohm   d) ohmmeter
Ans: c) Ohm

3. In a simple circuit, why does the bulb glow when you close the switch?
a) The switch produces electricity.           b) Closing the switch completes the circuit.
c) Closing the switch breaks the circuit.  d) The bulb is getting charged.
Ans: b) closing the switch completes the circuit

4. Kilowatt-hour is the unit of
a) resistivity   b) conductivity   c) electrical energy   d) electrical power
Ans: c) electrical energy

II. Fill in the blanks

1. When a circuit is open, cannot pass through it.   Ans: current
2. The ratio of the potential difference to the current is known as.   Ans: Resistance
3. The wiring in a house consists of circuits.    Ans: parallel
4. The power of an electric device is a product of and.  Ans: voltage and current
5. LED stands for.    Ans: Light Emitting Diode

III. State whether the following statements are true or false:
If false correct the statement.

1. Ohm’s law states the relationship between power and voltage.
Ans: False. Ohm’s law states the relationship between the potential difference and the current.

2. MCB is used to protect household electrical appliances. Ans: True.

3. The SI unit for electric current is the coulomb.
Ans: False. The SI unit for electric current is the Ampere.

4. One unit of electrical energy consumed is equal to 1000 kilowatt-hours.
Ans: False. One unit of electrical energy consumed is equal to 1000watt hour.

5. The effective resistance of three resistors connected in series is lesser than the lowest of the individual resistance.
Ans: False. The effective resistance of three resistors connected in series is greater than the highest of the individual resistance.

IV. Match the items in column-I to the items in column-II:

 1. Electric current (a) Volt 2. Potential difference (b) Ohmmeter 3. Specific resistance (c) Watt 4. Electrical power (d) Joule 5. Electrical energy (e) Ampere

1. (e) Ampere
2. (a) Volt
3. (b) Ohmmeter
4. (c)Watt
5. (d) Joule

V. Assertion and Reason
Mark the correct choice as
a) if both the assertion and the reason are true and the reason is the correct explanation of the assertion.
b) if both the assertion and the reason are true, but the reason is not the correct explanation of the assertion.
c) if the assertion is true, but the reason is false.
d) if the assertion is false, but the reason is true.

1. Assertion: Electric appliances with a metallic body have three wire connections.
Reason: Three-pin connections reduce the heating of the connecting wires.
Ans : (c) The assertion is true, but the reason is false.

2. Assertion: In a simple battery circuit the point of highest potential is the positive terminal of the battery.
Reason: The current flows towards the point of the highest potential.
Ans : (c) The assertion is true, but the reason is false.

3. Assertion: LED bulbs are far better than incandescent bulbs.
Reason: LED bulbs consume less power than incandescent bulbs.
Ans : (a) Both the assertion and the reason are true and the reason is the correct explanation of the assertion.