Skip to main content

Electricity


 



  1. Why is Tungsten metal selected for making filaments of incandescent lamp bulbs?
  2. Which will offer more resistance a 50W lamp or 25W lamp bulb and how many times?
  3. Why is much less heat generated in long electric than in filaments of electric bulb?
  4. What is superconductivity? Why is the research in superconductivity very important?
  5. What is the effect on resistivity of a pure metal with the increase in temperature?
  6. A torch bulb is rated at 3V and 600mA. Calculate it’s a) Power b) Resistance c) Energy consumed if it is lighted for 4 Hrs.
  7. Find the net power consumed by the two resistors R1 and R2 connected in series to a source of V volts.
  8. In a resistance R1 a current of 1A is passed. What is the amount of electrical energy dissipated in 1second?
  9. Two identical resistors each of resistance 10 ohm are connected 1) in series 2) in parallel, in line to a battery of 6volts. Calculate the ratio of power consumed in the combination of resistors in the two cases.
  10. A bulb is rated at 220V- 100W. What is its resistance? Five such bulbs burn for 4 hrs. What is the energy consumed? Calculate the cost if the rate is 50paise per unit?
  11. Express ohm’s law mathematically. Draw a circuit diagram to verify Ohm’s law. Present the relationship between the voltage applied across a conductor and the current flowing through it graphically.
  12. Two lamps rated 100W, 220V and 25W, 220V are connected in parallel to 220V supply. Calculate the total current through the circuit.
  13. A copper wire has a diameter of 0.5mm and resistivity of . How much of this wire is required to make a 10 ohm coil?How are ammeter and voltmeter connected in circuit? What are the ideal resistances for these components?How does the resistance of wire change when 1) Its length is doubled 2) Area is doubled?An electric kettle rated 1000W, 220V is used to bring water at 20 degrees to its boiling point. If the kettle is switched on for 10 minutes. Calculate:


  1. The resistance of the element of kettle
  2. Current flowing through the element

 


 


-------------------------------------------------------------------------------------------------------
www.cbsekey.com
Other Educational Portals
English | cbse | Science | Mathematics


 


 


 



Labels:

Comments

Post a Comment

Popular posts from this blog

The Missing Mail | Class IX - Interact in English

NCERT / CBSE Literature Reader for English Course (Communicative) Important Exercise Questions Q.3: (a) Why is Ramanujam worried about getting his daughter married? Give four reasons. (b) How does the postman console and guide Ramanujam and his family during each of the instances you have listed in 3 (a)? Ans 3(a): Ramanujam is worried as he could not find a suitable match to marry his daughter off which was getting delayed because of different reasons. The four causes of his worriedness are - (i) Sometimes horoscopes did not match, (ii) Sometimes the girl’s appearance were not approved, (iii) At times there were problems of too much dowry and other financial matters, (iv) The season was closing with only three more auspicious dates left, whereas, he was not able to finalise any alliance by that time. Ans 3(b): First instance - When Ramanujam said that horoscopes did not agree Thanappa consoled and guided him by saying that he should not utter inauspicious words and when the God wills
Post a Comment
Read more

Carbon and it's Compounds

Introduction Carbon is an element which is of immense significance to us in both its elemental form and in the combined form. Bonding in Carbon - The Covalent Bond Although there are more than hundred elements around us we do not find these elements in their native form in nature. This is because most of these elements are highly reactive. Properties of Covalent Compounds A covalent bond can be formed in different ways. When a bond is formed by mutual sharing of one pair of electrons it is known as a 'single covalent bond', or simply 'a single bond'. Types of Covalent Bonds Types of covalent bonds are Single Bond, Double Bond , Triple Bond. Tetravalency in Carbon A carbon atom has a total of six electrons occupying the first two shells, i.e., the K-shell has two electrons and the L-shell has four electrons. Allotropes of Carbon The existence of one element in different forms, having different physical properties, but similar chemical properties is known as allotropy. Am
7 comments
Read more

ENGLISH (Communicative) Sample Question Paper 5

Sample Paper – 2009 Class – XSubject – ENGLISH (Communicative) General instructions: The paper consist of FOUR sections: SECTION A (READING) - 20 Marks SECTION B (WRITING) - 30 Marks SECTION C (GRAMMAR) - 20 Marks SECTION D (LITERATURE) - 30 Marks Attempt all the questions. Do not write anything on the question paper. All the answers must be correctly numbered as in the question paper. And written in the answer sheets provided to you. Attempt all questions in each section before going on to the next section. Read each question carefully and follow the instructions. Strictly adhere to the word limit given with each question. Marks will be deducted for exceeding the word limit. SECTION A (READING) – 20 MARKS A1. Read the following passage and answer the following questions: [12] THE TUITION TRAP 1. Given the general awareness of the woeful condition of our State sch
1 comment
Read more