Standard 10 - Physics Answer Key

First Terminal Evaluation 2015 Physics Answer Key Std 10

1. Red

2. 200W
3. Brush
4. Copper
5. a. AC Generator
   b. graph of AC
6. a. Heating Effect
   b. Chemical Effect
7. a. Incandescent lamp
   b. Fluorescent lamp
8. a. Inductor
   b. It works only in AC
9. Armature.
   Heavy, To avoid ring and brush, to avoid electric spark
10. a. Heat is not developed in R2. The Heat in R1 increases
    b. the current passes through the switch, no current flows through R2. So the effective resistance decreases and current in the circuit increases and R1 is heated more.
11. a. Greater
    b. Greater Thickness
    c. To decrease heat
12. a. 3 phase AC generator
    b. No. There is Zero potential
13. a. R= V2/P = 400 x 400 / 800 = 200 ohm
    b. P = V2/R = 200 x 200 / 200 = 200 W
14. a. Moving coil Loudspeaker
    b. A=diaphragm
    B=Voice Coil
    c. Motor Principle
    d. Electric Motor
15. a. Q
    b. P
    c. resistivity is same
    d. Q
16. a. A & C
    b. D
    c. In A&C there is no self Induction as it is dc. So there is no decrease in the voltage
    In D there is soft iron core and ac. So rate of self induction is more and voltage decreases.
17. a. outwards
    b. Fleming's Left hand rule
    c. change the direction of the magnetic field too.