+2 physics one mark questions - Current Electricity - Set 3

                Tamil Nadu +2 physics important one mark questions

                                   Current electricity - Set 3

15. The unit of conductivity is

(a) ohm-m             (b) ohm                 (c) mho                 (d) mho-m^-1

16. Drift velocity in metals is the order of

(a) 0.1ms^-1             (b) 1cms^-1              (c) 0.1cms^-1            (d) 1ms^-1

17. The emf of leclanche cell is

(a) 1.08 V              (b)  1.5 V                (c)  2 V                  (d)  1.8 V

18. The internal resistance of a secondary cell is

(a) Low                 (b) high                  (c) very low           (d) very high

19. For metals , when the temperature increases their resistance

(a) Decreases                                               (b) increases                  

(c) Remains constant                                    (d)increases & then decreases

20. The resistance of mercury is zero at the temperature

(a)3.2 K                 (b)4.2 K                 (c) 4.2 °c               (d) 0  K

21. The unit of magnetic induction is

(a) Tesla                (b)Wb/m²               (c) Wbm²               (d) Both a and b