Q 5 – A student carries out an experiment and plots the V-I graph of three samples of Nichrome wire with resistances R1 R2 and R3 respectively. Which of the following is correct?
Q 12 – Ohm’s law states that: (a) Resistance increases as current increases (b) Resistance decreases as current increases (c) Resistance increases as voltage increases (d) Current increases as voltage increases
Q 32 – Few resistors are connected in series to a battery and formed a closed electric circuit, then the current through each resistor in the closed electric circuit is the same.True/ False
Q 39 – Which of the following is the purpose of connecting a battery in an electric circuit?
a. To maintain resistance across the conductor. b. To vary resistance across the conductors. c. To maintain constant potential difference across the conductor. d. To maintain varying potential difference across the conductor.
Q 45 – Two bulbs A and B are connected in series with a cell. Resistance of bulb A is Ra and resistance of bulb B is Rb. The ratio of the currents in bulb A tobulb B is ______________.
Q 52 Two devices are connected between two points say A and B in parallel. The physical quantity that will remain the same between the two points is a. current b. voltage c. resistance d. None of these
Q 54. A fuse wire repeatedly gets burnt when used with a good heater. It is advised to use a fuse wire of a. more length b. less radius c. less length d. more radius
Q 57. The resistivity does not change if a. the material is changed b. the temperature is changed c. the shape of the resistor is changed d. both material and temperature are changed
Q 63. Two resistors of resistance 2 and 4 when connected to a battery will have
(a) same current flowing through them when connected in parallel (b) same current flowing through them when connected in series (c) same potential difference across them when connected in series (d) different potential difference across them when connected in parallel
(b) same current flowing through them when connected in series
Q 64. By using only two resistors, R1 and R2, a student is able to obtain resistances of 3, 4, 12, and 16. The values of R1 and R2 (in ohms) are: (a) 3, 4
Q 65. Three equal resistances, when combined in series, are equivalent to 90 Ω. Their equivalent resistance when combined in parallel will be _________________. (a) 270 Ω
Q 67. A wire of resistance R is cut into n equal parts. These parts are then connected in parallel. The equivalent resistance of the combination will be (a) n R
Q 68. The resistance of resistor 1 is twice the resistance of resistor 2. Then two are connected in parallel and a potential difference is maintained across the combination. Then:
(a) the current in resistor1 is twice that in resistor2 (b) the current in resistor1 is half that in resistor 2 (c) the potential difference across resistor1 is twice that across resistor2 (d) the potential difference across resistor1 is half that across.