11. The current in a metallic conductor is plotted against voltage at two different temperatures T and T2. Which is correct :- Current 2 (1) T Voltage (2) T 12. Copper and silicon are cooled from 300 K to 60 K; the specific resistance :- (1) decreases in copper but increases in silicon (2) increases in copper but decreases in silicon (3) increases in both (4) decreases in both (sin120) 13. d dx (1) cos120 (2) 120cos120 (3) 0 (4) None of these 14. dv If v (t+2) (t+3) then acceleration at dt t = 1 sec :- (1) 5 m/s (2) 7 m/s (3) 2 m/s (4) 4 m/s