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### Second term Exam Standard 10 -Physics (draft)

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Second Term Exam Standard 10 Physics - Answer key

1. (a) (1)
2. magenta (1)
3. (b). resistor, capacitor, diode, transistor (1)
4. decibel (dB) (1)
5. (b). The number of turns of coils in each armature is same (1)
6. a). P- Radio waves , Q – Gamma rays (1)
b). Gamma rays (1)
7. a). (d) (1)
8. I = P/V = 1500/250 = 6A (1)
H = Pxt = 1500 x 5 x 60 = 450000 J
OR
P x Hr /1000 = 1500 x (5/60 ) /1000 = .13 Unit(kWh) (1)
9. a). Earth pin should be connected to the metallic body part of the electric iron.(1)
b). Earth pin connected to the earth – If the live wires in contact with the metallic body , more current flows as it is connected to earth. This causes the breakage of fuse. (2)
10. a). 256 Hz.
b). The amplitude of the sound increases. It is due to resonance (2)
11. a). Scattering (1)
b). violet, indigo, blue (1)
c). size of the particles (1)
12. a). dark/ black (1)
b). yellow. Yellow light contains red and green.
Cyan. Cyan light contains green and blue - write any one (2)
OR
a). white (1)
b). These secondary colours are the combinations of the primary colours Red, Green and Blue. Due to persistence of vision it appears as white (2)
13. a). The electrical oscillations corresponding to the sound waves (1)
b). amplitude (1)
c). draw the graph of half wave dc (1)
14. a). Cyan (1)
b) X= green, Y= Blue (1)
c). cyan contains green and blue, it splits when the dispersion taken place. (1)
15. a). f= v/l = 340/.01m = 34000 Hz (2)
b). No. We can hear only the sound waves of frequency between 20Hz and 20000Hz.(1)
16. a). Main fuse should be connected in the phase line instead of neutral line.
Switch S2 is in earth line. It must be in the phase line (2)
b). At the place of section fuse (1)
c). It save the circuit from short-circuit, overloading, etc. It is easy to re install. (1)
17. a). The brightness of the bulb increases. When the iron core is removed, the rate of self induction decreases. (2)
b). when S1 and S2 are switched on, The bulb will not glow.
When S1 and S3 switched on, The brightness of the bulb increases.(Malayalam Med) (1)
c). The circuit becomes short-circuit and it causes the breakage of fuse. (1)

We can finalise the key after discussions........