The following graph shows current versus voltage values of some unknown conductor. What is the resistance of this conductor?

(a)

2 ohm

(b)

4 ohm

(c)

8 ohm

(d)

1 ohm

A toaster operating at 240 V has a resistance of 120 Ω. The power is ______.

(a)

400 W

(b)

2 W

(c)

480 W

(d)

240 W

What is the value of resistance of the following resistor?

(a)

100 k Ω

(b)

10 k Ω

(c)

1 k Ω

(d)

1000 k Ω

A wire connected to a power supply of 230 V has power dissipation P₁. Suppose the wire is cut into two equal pieces and connected parallel to the same power supply. In this case power dissipation is P₂. The ratio \(\frac{P_2}{P_1}\) is ______.

(a)

1

(b)

2

(c)

3

(d)

4

In a large building, there are 15 bulbs of 40 W, 5 bulbs of 100 W, 5 fans of 80 W and 1 heater of 1 kW are connected. The voltage of electric mains is 220 V. The maximum capacity of the main fuse of the building will be ______.

(a)

14 A

(b)

8 A

(c)

10 A

(d)

12 A

The internal resistance of a 2.1 V cell which gives a current of 0.2 A through a resistance of 10 Ω is ______.

(a)

0.2 Ω

(b)

0.5 Ω

(c)

0.8 Ω

(d)

1.0 Ω

The colour code on a carbon resistor is red - red - black. The resistance of the resistor is ___________.

(a)

\(2.2\Omega \)

(b)

\(22\Omega \)

(c)

\(220\quad 2.2\Omega \)

(d)

\(2.2k\Omega \)

When 'n' resistors of equal resistance (R) are connected in series and in parallel respectively, then the ratio of their effective resistance is ______________

(a)

1: n²

(b)

n²: 1

(c)

n: 1

(d)

1: n

The resistance of the wire varies inversely as _________________.

(a)

area of cross section

(b)

resistivity

(c)

length

(d)

temperature

Calculate the mobility of a free electron in an electric field of 10⁺²N/C.

(a)

10^-4m²V^-1s^-1

(b)

10^-5m²V^-1s^-1

(c)

10^-3m²V^-1s^-1

(d)

10⁵m²V^-1s^-1

Carbon are furnaces produce temperature upto________

(a)

1500^oC

(b)

2000^o C

(c)

2500^oC

(d)

3000^oC

The unit of current density is________

(a)

Am^-2

(b)

Am²

(c)

A²m-²

(d)

A^-2m^-2

The reciprocal of conductivity is________

(a)

specific conductance

(b)

specific resistance

(c)

resistance

(d)

conductance

The transition temperature of mercury is________

(a)

4.2°C

(b)

4.2 K

(c)

2.4°C

(d)

2.4K

In a carbon resistor, the third ring represents___________

(a)

powers of zeros

(b)

powers of ten

(c)

ten

(d)

infinity

The temperature coefficient of resistance is negative for_________

(a)

for metals

(b)

ebonite

(c)

(a) and (b)

(d)

none

Ohm's law is applicable only for_______________

(a)

complicated circuits

(b)

primary circuits

(c)

simple circuits

(d)

secondary circuits

In Kirchhoff's II law the current in clockwise direction is taken as________

(a)

positive

(b)

negative

(c)

neutral

(d)

no direction

In the case of meter bridge manganin wire is used because it has_________

(a)

low temperature coefficient of resistance

(b)

high temperature coefficient of resistance

(c)

temperature coefficient of resistance is zero

(d)

temperature coefficient of resistance is maximum

Potentiometer is an instrument used for the measurement of____________

(a)

current

(b)

resistance

(c)

capacitance

(d)

potential difference