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प्रश्न
The voltage applied to a given rheostat is made four times its initial value. By what factor will be resistance of the rheostat change?
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उत्तर
The resistance of the rheostat will not change at all as it does not depend on the voltage applied across it.
संबंधित प्रश्न
Complete the following :-
(a)
A piece of wire of resistance R is cut into five equal parts. These parts are then connected in parallel. If the equivalent resistance of this combination is R’, then the ratio `"R"/"R'"` is ______.
Two resistors of 4Ω and 6 Ω are connected in parallel to a cell to draw 0.5 A current from the cell.
(i) Draw a labelled circuit diagram showing the above arrangement.
(ii) Calculate the current in each resistor. What is an Ohmic resistor?
An electrical appliance has a resistance of 25 Ω. When this electrical appliance is connected to a 230 V supply line, the current passing through it will be:
(a) 0.92 A
(b) 2.9 A
(c) 9.2 A
(d) 92 A
If the length of a wire is doubled by taking more of wire, what happens to its resistance?
How does the resistance of a wire change when:
its length is tripled?
A p.d. of 4 V is applied to two resistors of 6 Ω and 2 Ω connected in series. Calculate:
(a) the combined resistance
(b) the current flowing
(c) the p.d. across the 6 Ω resistor
A given metallic wire of resistance R is doubled on itself. What will be its new resistance?
State the effect of rise in temperature on the resistance of semi-conductors.
