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34) V = IR ie voltage/p.d is directly proportional to resistance, n current is inversely proportional to resistance.
So, when R increases, terminal pd will also increase.
(remember cell emf = terminal pd + lost volts due to internal resistance)
also, when R increases, current in the circuit will decrease.
Plus, emf of the cell is unchanged.
So, the ans is D, max output will be whn R = r, ----> http://www.s-cool.co.uk/a-level/phy...tential-dividers/revise-it/potential-dividers
37) B
when light falls on the LDR, its resistance decreases.
And, as we know pd is proportional to resistance, so when LDR's resistance falls, the pd across it will decrease.
And, since this is a potential divider circuit, (see abv), the pd across the resistor will increase ( voltage across R = [R/(R + LDR)] * V )
P.S. m nt sure abt 17 n 32. will gt back 2 u on tht, IA.
Hope u gt it!! All the best!!
So, when R increases, terminal pd will also increase.
(remember cell emf = terminal pd + lost volts due to internal resistance)
also, when R increases, current in the circuit will decrease.
Plus, emf of the cell is unchanged.
So, the ans is D, max output will be whn R = r, ----> http://www.s-cool.co.uk/a-level/phy...tential-dividers/revise-it/potential-dividers
37) B
when light falls on the LDR, its resistance decreases.
And, as we know pd is proportional to resistance, so when LDR's resistance falls, the pd across it will decrease.
And, since this is a potential divider circuit, (see abv), the pd across the resistor will increase ( voltage across R = [R/(R + LDR)] * V )
P.S. m nt sure abt 17 n 32. will gt back 2 u on tht, IA.
Hope u gt it!! All the best!!