An electric toaster uses nichrome for its heating element. When a negligibly small current passes through it, its resistance at room temperature (27.0 °C) is found to be 75.3 Ω. When the toaster is connected to a 230 V supply, the current settles, after a few seconds, to a steady value of 2.68 A. What is the steady temperature of the nichrome element? The temperature coefficient of resistance of nichrome averaged over the temperature range involved is 1.70 × 10–4 °C–1
The resistance of the platinum wire of a platinum resistance thermometer at the ice point is 5 Ω and at the steam point is 5.23 Ω. When the thermometer is inserted into a hot bath, the resistance of the platinum wire is 5.795 Ω. The temperature of the bath is:
A network of resistors is connected to a 16 V battery with an internal resistance of , as shown in the figure. The equivalent resistance of the network is:
A network of resistors is connected to a 16 V battery with an internal resistance of , as shown in the figure. The current in resistor between B and C will be:
A network of resistors is connected to a 16 V battery with an internal resistance of , as shown in the figure. The voltage drop across AB is:
1. 2 V
2. 25 V
3. 4 V
4. 6 V
A battery of 10 V and negligible internal resistance is connected across the diagonally opposite corners of a cubical network consisting of 12 resistors each of resistance (as shown in the figure). The total current in the network is:
The current in the branch AB in the given network is:
1. 5/8 A
2. 5/2 A
3. 15/8 A
4. 3/2 A
The four arms of a Wheatstone bridge have the following resistances as shown in the figure. A galvanometer of 15Ω resistance is connected across BD. What is the current through the galvanometer when a potential difference of 10 V is maintained across AC?
1. 4.87 mA
2. 3.72 mA
3. 5.01 mA
4. 2.65 mA
In a meter bridge (shown in the figure), the null point is found at a distance of 33.7 cm from A. If now a resistance of 12 is connected in parallel with S, the null point occurs at 51.9 cm. The values of R and S are respectively:
A resistance of draws current from a potentiometer. The potentiometer has a total resistance (as shown in the figure). A voltage V is supplied to the potentiometer. What is the voltage across R when the sliding contact is in the middle of the potentiometer?